Bouteloua curtipendula

This native perennial grass is about 2–2½' tall and unbranched. The culms are light green, glabrous, and terete (round in cross-section); later during the fall, they become light tan. The alternate leaves are more common toward the base of each culm. The leaf blades are up to 8" long and ¼" across; they are light green to green, mostly hairless, and rough along their margins. However, toward the base of each leaf blade, there is often a few white hairs that are somewhat deciduous. The larger leaf blades often have prominent central veins. The leaf sheaths are light green, finely ribbed, and hairless. Each ligule has a ring of short fine hairs. The nodes are slightly swollen, rough, and often reddish or brownish green; the portion of the culm near each node may be tinted similarly as well. The culm terminates in a narrow raceme up to 10" long that consists of 30-50 pendulous spikes. Each spike is about ½" long and consists of about 5 spikelets. Each spikelet consists of a pair of linear-lanceolate glumes and a pair of linear-lanceolate lemmas; only one of the lemmas is fertile. The spikelets are up to 1/3" long and greenish red while the flowers are blooming, but they later become tan. Each glume tapers into an acute tip, while the tip of each lemma is often notched on either side. The anthers of the fertile lemmas are bright red to brownish red, while their stigmas are white and feathery. The blooming period occurs from mid-summer to early fall. The spikes of the inflorescence persist into the fall, after which they fall to the ground in their entirety (the glumes are non-persistent). Each fertile lemma bears a single grain. The root system has fibrous roots and short rhizomes. Side Oats Grama often forms tight bunches of culms from its rhizomes, although it also occurs as scattered plants. In moist areas where there is little competition, it may form a dense sod.

Side Oats Grama is the only Bouteloua sp. (Grama Grass) that is fairly common in Illinois. Two other species, Bouteloua gracilis (Blue Grama) and Bouteloua hirsuta (Hairy Grama), are shorter grasses that are more common in states of the Great Plains. These latter two species have curious racemes of spikes that are shaped like eye-lashes; they tend to be held horizontally in relation to the ground. Among the grasses of Illinois, the inflorescence of Side Oats Grama is really quite unique as the spaced out spikes tend to droop on one side of the raceme's central axis. As a result, this interesting grass is easy to identify. Side Oats Grama is a warm-season grass with a C4 metabolism (a trait it shares with other Grama Grasses). This enables it to tolerate the hot dry summers of the Midwest and other areas further to the west.

General: Side-oats grama is a deep rooted, perennial grass. The plants crown will spread very slowly by means of extremely short, stout rhizomes. A mid-grass in height, it has rather wide leaves and a very distinct inflorescence consisting of a zigzag stalk with small compressed spikes dangling from it at even intervals. The short spikes dangle from one side of the stalk, thus providing the plant with its common name. In the vegetative state the grass is easily recognized by the long, evenly spaced hairs attached to the margins of the leaf near its base. Side-oats grama possesses the C-4 photosynthetic pathway common to warm-season grasses (Waller and Lewis, 1979).

Distribution: For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site. One of the most widely distributed of the grama grasses. It has a widespread distribution eastward from the Rocky Mountains to near the east coast except in the southeast.

Habitat: Side-oats grama grows effectively in the dryer mid-grass prairie section of the Great Plains that has an annual rainfall of 12-20 inches. This species occurs naturally in mixed stands with blue grama (Bouteloua gracilis) and little bluestem (Schizachyrium scoparium). This grass is better adapted to calcareous and moderately alkaline soils than to neutral or acidic soils (Leithead etal., 1971)

Sideoats grama's North American distribution stretches from southern Canada to Mexico. In Canada it occurs in Saskatchewan [42], Manitoba, and Ontario [78]. In the northern United States it is distributed from Oregon to Maine [206]; in the eastern states south to Florida [230], excluding Vermont, New Hampshire, Delaware, Massachusetts, Rhode Island, and North Carolina [206]; and in the western United States to California and Texas. Its distribution continues south through Mexico to Central and South America [42,78,105]. Bouteloua curtipendula var. caespitosa is found primarily in the southern part of the species' range, from the southwestern United States to South America. Bouteloua curtipendula  var. curtipendula is found in the northern part of the species' range, from the southwestern United States to Canada [49,73,104]. Plants Database provides maps of sideoats grama's distribution and distributions of the 2 varieties.

Side Oats Grama is locally common in sunny upland areas along the Mississippi and Illinois River; it is absent in SE Illinois and parts of central Illinois, and uncommon to occasional elsewhere (see Distribution Map). Habitats include various kinds of hill prairies, dry upland prairies (including gravel prairies & dolomite prairies), thinly wooded bluffs and barrens, limestone glades, and areas along railroads. This grass is often used in prairie restorations, from which it occasionally escapes into adjacent areas. As a result, Side Oats Grama is becoming more common in some areas of the state.

More info on this topic.

This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

BLM PHYSIOGRAPHIC REGIONS [16]:

3 Southern Pacific Border

5 Columbia Plateau

6 Upper Basin and Range

7 Lower Basin and Range

8 Northern Rocky Mountains

9 Middle Rocky Mountains

10 Wyoming Basin

11 Southern Rocky Mountains

12 Colorado Plateau

13 Rocky Mountain Piedmont

14 Great Plains

15 Black Hills Uplift

16 Upper Missouri Basin and Broken Lands

ALAZARCACOCTFLGAHIIDIL IAKSKYLAMEMDMIMNMSMOMTNENVNJNMNYNDOHOKORPASCSDTNTXUTVAWAWVWIWYDC

MBONSK

MEXICO

Erucaria glabra Cerv.:
Mexico (Mesoamerica)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Bouteloua pendula hort. ex Lag.:
Mexico (Mesoamerica)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Bouteloua acuminata (E. Fourn.) Griffiths:
Mexico (Mesoamerica)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Bouteloua racemosa Lag.:
Mexico (Mesoamerica)
Bolivia (South America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Atheropogon medius E. Fourn.:
Mexico (Mesoamerica)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Aristida secunda Larrañaga:
Uruguay (South America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Widespread from Maine and Ontario west to Saskatchewan and Washington, south to Florida, and west to California (Kartesz 1999).

Side-oats is adapted to a broad range of sandy to clayey textured soils; it is least tolerant of loose sands and dense clays. The best stands of side-oats are found on medium to fine texture upland soils. This species has shown varying tolerance to soil salinity from weak to moderate. Side-oats is moderately drought tolerant, but less than blue grama. It is moderately tolerant of semi-shaded conditions and can be found in open woodlands. It will sustain damage from wildfires when actively growing and under drought stress conditions, but is fairly tolerant of fire in a dormant state. It is also fairly tolerant of spring flooding. It probably has the widest range of adaptation of any of the warm-season perennial grass plants. It grows in combination with tall warm-season grasses such as big bluestem (Andropogon gerardii) and switchgrass (Panicum virgatum) all the way to the short grass plants such as buffalo grass (Bouteloua dactyloides) and blue grama (Boutelouagracilis). Thus, it can successfully grow in a variety of climates and habitats in the continental U.S.

More info for the terms: caryopsis, resistance, root crown, warm-season

Sideoats grama is a native, warm-season perennial grass that grows 3 to 39 in (8-100 cm) tall [78,196]. Bouteloua curtipendula var. curtipendula culms occur singly or in small clusters from creeping rhizomes, while B. curtipendula var. caespitosa culms are in large clumps arising from a common root crown [42]. Sideoats grama leaves are 0.11 to 0.15 inch (3-4 mm) wide and flat at maturity [78,93]. Inflorescences are elongate and may bear over 20 and up to 80 deciduous spikes [49,78,105], each of which bears 3 to 8 spikelets hanging to one side [78,93,128]. The fruit is an awnless caryopsis [49].

Sideoats grama typically has many coarse, fibrous roots [205], which may grow 2 to 4 feet (0.6-1.2 m) in length and spread laterally 1 to 1.5 feet (0.3-0.5 m) in the top 2 to 4 inches (5-10 cm) of soil [214]. In a Nebraska study sideoats grama plants had a range of 170 to 423 roots per plant [215]. Roots of sideoats grama are well adapted to growth in dry conditions [214]. They extend rapidly into wet subsurface levels, reducing plant dependency on more variable moisture conditions at the surface soil [188]. More information on drought resistance of sideoats grama is included in Management Considerations.

Perennials, Terrestrial, not aquatic, Rhizomes present, Rhizome short and compact, stems close, Rhizome elongate, creeping, stems distant, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems solitary, Stems terete, round in cross section, or polygonal, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly basal, below middle of stem, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or l oose, Leaf sheath smooth, glabrous, Leaf sheath hairy at summit, throat, or collar, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Inflorescence terminal, Inflorescence with 2 or more spikes, fascicles, glomerules, heads, or clusters per culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence branches more than 10 to numerous, Inflorescence branches 1-sided, Flowers bisexual, Spikelets sessile or subsessile, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Inflorescence branches deciduous, falling intact, Spikelets secund, in rows on one side of rachis, Rachilla or pedicel glabrous, Glumes present, empty br acts, Glumes 2 clearly present, Glumes distinctly unequal, Glumes equal to or longer than adjacent lemma, Glume equal to or longer than spikelet, Glumes 1 nerved, Lemma coriaceous, firmer or thicker in texture than the glumes, Lemma 3 nerved, Lemma glabrous, Lemma rugose, with cross wrinkles, or roughened, Lemma apex dentate, 2-fid, Lemma apex dentate, 3-5 fid, Lemma teeth unequal. central tooth longer, Lemma awnless, Lemma mucronate, very shortly beaked or awned, less than 1-2 mm, Lemma with 3 awns, Lemma awn less than 1 cm long, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea shorter than lemma, Palea 2 nerved or 2 keeled, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Perennial with short, slender, scaly rhizomes. Culms tufted, erect, 30–100 cm tall. Leaf sheaths glabrous or nearly so; leaf blades flat or slightly involute, 20–30 cm, 1–5 mm wide, both surfaces and margins scabrous, base pubescent; ligule ca. 1 mm. Inflorescence axis 15–25 cm; racemes 10–50, 1–2 cm, purplish, secund along axis, usually nodding, with 3–6 (–10) appressed or ascending spikelets, falling entire. Spikelets 4.5–10 mm; lower glume linear-lanceolate, 2.5–4 mm; upper glume lanceolate, 4(–7) mm; lemma of fertile floret usually somewhat exceeding glumes, acuminate, lateral veins extended into ca. 1 mm mucros; palea slightly longer than lemma; 2nd floret rudimentary, with long central awn and 2 shorter laterals, or greatly reduced, or lacking. Fl. and fr. summer to autumn. 2n = 28, 35, 40, 42, 56, 70.

Chloris curtipendula Michaux, Fl. Bor.-Amer. 1: 59. 1803; Atheropogon curtipendulus (Michaux) E. Fournier; Cynodon curtipendulus (Michaux) Raspail; Dinebra curtipendula (Michaux) P. Beauvois; Eutriana curtipendula (Michaux) Trinius.

More info for the term: cover

Sideoats grama is widely distributed across the plains, prairies, and lower mountains of much of North America [42,93]. It grows on a wide variety of landforms and habitats, but is most abundant and important in the central and southern mixed-grass prairies [214].

Elevation: Sideoats grama occurs at a wide elevational range that varies with location.  In the southwestern United States, it is found from 3,000 to 8,000 feet (914-2,440 m) elevation [205]. Ranges are similar for both varieties. Bouteloua curtipendula var. curtipendula occurs at elevations of from less than 328 feet (100 m) in southern Texas to over 8,200 feet (2,500 m) in the northwestern United States. Bouteloua curtipendula var. caespitosa occurs from 650 to 8,200 feet (200-2,500 m) [77]. The following table provides a summary of the elevational ranges for sideoats grama:

AZ below 2,500 feet to 7,500 feet (760-2,130 m) [96,197] CA below 6,230 feet (1,900 m) [91] CO 3,500 to 7,500 feet (1,070-2,130 m) [84] NM 5,500 to 7,500 feet (1,680-2,130 m) [128] SD 1,265 to 1,493 feet (386-455 m) [94] UT 3,215 to 8,000 feet (980-2,440 m) [217]

Climate/moisture regime: Sideoats grama grows under a wide variety of climate conditions. A study of establishment of seeded-in grasses in pinyon-juniper woodlands in Arizona and New Mexico found sideoats grama was adapted to warm-moist and hot-dry sites, but not cold, cool, warm-dry, or hot-moist sites [100]. A study of water-use of plains grasses suggests sideoats grama requires a fairly large supply of water for limited periods. Sideoats grama showed inefficient water-use relative to other plains grasses, especially in cold weather [131]. According to Fulbright and others [68], sideoats grama has a low soil moisture requirement, but requires at least 15 inches (380 mm) of annual precipitation. Story [192] reported good stands of sideoats grama developed in areas with 12 to 16 inches (305-406 mm) of annual rainfall in the Southwest. In the central Great Plains, stand development of sideoats grama was greatest on fine-textured upland soils with 17 to 20 inches (432-508 mm) of annual rainfall. On Wisconsin prairie and savannas, sideoats grama occurs on sites characterized by cyclic mild to severe summer drought, less than 45 inches (1140 mm) annual snowfall, and a mean summer temperature of 68 degrees Fahrenheit (20 °C) [27].

Soils/landform: Sideoats grama is adapted to a broad spectrum of soils, from sands to clays [86,212]. It is least adapted to loose sand and dense clay, and has best stand development on medium to fine-textured soils [212]. Sideoats grama grows on shallow to deep soils. It does not grow well on wet soils, although it is moderately tolerant of spring flooding [186]. In the Intermountain West, sideoats grama grows well on sandy loam to clay loam [50]. In North Dakota it is found on shallow soils with textures ranging from loamy sands through loams and silt loams to silty clay loams [224]. Sideoats grama is an important component of grasslands on clay soils in the northern Great Plains [70] and on loess soils in the central Great Plains [204]. In Kansas shortgrass prairie sideoats grama grows on fine-textured, silty clay loams, especially in areas with deep soils [3]. Bush and Van Auken [34] reported sideoats grama aboveground, belowground, and total dry mass increased with increasing soil depth of  up to 71 inches (180 cm).

Sideoats grama has weak to moderate tolerance to saline soils [212] but does well on calcareous or alkaline soils [68,122,140]. It often occurs on shallow limestone or dolomite soils [142] and on soils high in available nitrate. Sideoats grama is associated with moderate levels of soil water stress relative to other grama species [154]. In mixed-grass prairie of northern Wyoming and southern Montana, it occurs on shallow soils with low water-holding capacity and high infiltration rate, and does well with relatively high growing season precipitation and no available groundwater [110].

Studies in Texas provide information about the soil requirements of the different varieties of sideoats grama. Bouteloua curtipendula var. curtipendula grows mostly on loose, limey soils and on relatively good soils in less disturbed areas including native Texas prairies [49], while B. curtipendula var. caespitosa has higher cover on soils with higher clay content, pH, and organic matter [48]. However, according to Gould [77], Bouteloua curtipendula var. curtipendula grows best on loamy, well-drained soils, while B. curtipendula var. caespitosa is usually found on loose, sandy or rocky, well-drained limey soils.

Sideoats grama is well-adapted to steep, rocky slopes [50,122,154,205]. In Illinois sideoats grama is found in coarse soil on limestone outcrops [7,20,193]. It occurs on shale barrens in West Virginia [193]. Sideoats grama is common in washes and on low benches [20]. In the Southwest it grows on south- to west-facing slopes, dry hills, and mesas [105,128,197].

More info for the term: hardwood

Sideoats grama generally occurs in dry woods in the eastern United States and in
dry prairies and sandhills in the western states [73].
It is a major species in grasslands of the Great Plains, including tallgrass
prairie [113,174], mixed-grass prairie and shortgrass steppe [110,118], and in desert grasslands of the
Southwest [222]. Sideoats grama
is also found in ponderosa pine (Pinus ponderosa) forests, eastern hardwood
savannas [195],  southwestern oak (Quercus
spp.) and pinyon-juniper (Pinus-Juniperus spp.) woodlands and
savannas [112,165], and desert and semidesert
shrublands [102]. Sideoats grama is commonly associated with bluebunch wheatgrass (Pseudoroegneria spicata),
western wheatgrass (Pascopyrum smithii), little bluestem (Schizachyrium
scoparium), big bluestem (Andropogon gerardii var. gerardii),
Idaho fescue (Festuca idahoensis), prairie Junegrass (Koeleria
macrantha), blue grama (Bouteloua gracilis), black greasewood (Sarcobatus
vermiculatus), true mountain-mahogany (Cercocarpus montanus),
southwestern oaks, Colorado pinyon pine (Pinus edulis),
and several juniper species including redberry juniper (Juniperus pinchotii),
eastern redcedar (J. virginiana), oneseed juniper (J.
monosperma), Ashe juniper (J. ashei), alligator juniper (J.
deppeana), and Utah juniper (J.
osteosperma) [112,117,165].

The following list of publications includes selected classifications listing
sideoats grama as an indicator or dominant species in vegetation classifications.
AZ [12,117,197,211]

CO [11,81]

IA [207]

IN [17]

KS [120]

MO [150]

MT [30,80,179]

NB [167]

ND [82,143,223,224]

NM [12,54,56,92,117,137,166,197]

OH [74]

SD [94,200]

TX [89,132,198]

WI [43]

WY [37,94]

More info on this topic.

This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):

More info for the terms: cover, vine

SRM (RANGELAND) COVER TYPES [187]:

415 Curlleaf mountain-mahogany

416 True mountain-mahogany

417 Littleleaf mountain-mahogany

502 Grama-galleta

503 Arizona chaparral

504 Juniper-pinyon pine woodland

505 Grama-tobosa shrub

509 Transition between oak-juniper woodland and mahogany-oak association

601 Bluestem prairie

602 Bluestem-prairie sandreed

604 Bluestem-grama prairie

609 Wheatgrass-grama

611 Blue grama-buffalo grass

702 Black grama-alkali sacaton

703 Black grama-sideoats grama

704 Blue grama-western wheatgrass

705 Blue grama-galleta

706 Blue grama-sideoats grama

707 Blue grama-sideoats grama-black grama

708 Bluestem-dropseed

709 Bluestem-grama

710 Bluestem prairie

711 Bluestem-sacahuista prairie

712 Galleta-alkali sacaton

713 Grama-muhly-threeawn

714 Grama-bluestem

715 Grama-buffalo grass

716 Grama-feathergrass

717 Little bluestem-Indiangrass-Texas wintergrass

718 Mesquite-grama

720 Sand bluestem-little bluestem (dunes)

721 Sand bluestem-little bluestem (plains)

724 Sideoats grama-New Mexico feathergrass-winterfat

725 Vine mesquite-alkali sacaton

727 Mesquite-buffalo grass

728 Mesquite-granjeno-acacia

729 Mesquite

731 Cross timbers-Oklahoma

732 Cross timbers-Texas (little bluestem-post oak)

733 Juniper-oak

734 Mesquite-oak

735 Sideoats grama-sumac-juniper

801 Savanna

802 Missouri prairie

803 Missouri glades

More info on this topic.

This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

More info for the term: cover

SAF COVER TYPES [61]:

42 Bur oak

46 Eastern redcedar

66 Ashe juniper-redberry (Pinchot) juniper

67 Mohrs (shin) oak

68 Mesquite

236 Bur oak

237 Interior ponderosa pine

239 Pinyon-juniper

240 Arizona cypress

242 Mesquite

More info on this topic.

This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

KUCHLER [115] PLANT ASSOCIATIONS:

K016 Eastern ponderosa forest

K017 Black Hills pine forest

K023 Juniper-pinyon woodland

K031 Oak-juniper woodland

K032 Transition between K031 and K037

K037 Mountain-mahogany-oak scrub

K053 Grama-galleta steppe

K054 Grama-tobosa prairie

K058 Grama-tobosa shrubsteppe

K060 Mesquite savanna

K065 Grama-buffalo grass

K067 Wheatgrass-bluestem-needlegrass

K068 Wheatgrass-grama-buffalo grass

K069 Bluestem-grama prairie

K070 Sandsage-bluestem prairie

K071 Shinnery

K074 Bluestem prairie

K075 Nebraska Sandhills

K076 Blackland prairie

K081 Oak savanna

K083 Cedar glades

K084 Cross Timbers

K085 Mesquite-buffalo grass

K086 Juniper-oak savanna

K087 Mesquite-oak savanna

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

ECOSYSTEMS [69]:

FRES15 Oak-hickory

FRES21 Ponderosa pine

FRES30 Desert shrub

FRES31 Shinnery

FRES32 Texas savanna

FRES33 Southwestern shrubsteppe

FRES34 Chaparral-mountain shrub

FRES35 Pinyon-juniper

FRES38 Plains grasslands

FRES39 Prairie

FRES40 Desert grasslands

Side Oats Grama is locally common in sunny upland areas along the Mississippi and Illinois River; it is absent in SE Illinois and parts of central Illinois, and uncommon to occasional elsewhere (see Distribution Map). Habitats include various kinds of hill prairies, dry upland prairies (including gravel prairies & dolomite prairies), thinly wooded bluffs and barrens, limestone glades, and areas along railroads. This grass is often used in prairie restorations, from which it occasionally escapes into adjacent areas. As a result, Side Oats Grama is becoming more common in some areas of the state.

Cultivated in China [native to America].

Seed improved cultivars of this grass no deeper than ¼ inch on fine textured soils and ¾ inch on coarser textured soils. Planting with a grass seed drill on a firm, weed free seedbed at the rate of 2.5 to 5.0 pounds of pure live seed (PLS) is encouraged. Broadcasting at a higher seeding rate (50 to 100 percent increase) can be utilized on a previously prepared seedbed that will be culti-packed after seeding is completed. Increased seeding rate should also be used on bare areas, harsh sites, or on areas that require denser or quicker stand establishment. Seeding is more likely to be successful if moisture conditions are good and if mulch is used to retain moisture on the seeding site. Most seed germinates within 7 days under good field conditions. Seedling vigor is good when compared to other warm season grasses. Field germination, emergence and establishment of this species are better than other grama grasses. Protection from grazing is encouraged while seedlings are in the juvenile stage of growth.

The leafhoppers Flexamia pectinata and Laevicephalus minimus are specialist feeders of Side Oats Grama. Many grasshoppers feed on this prairie grass (see Grasshopper Table), as do the stinkbugs Moromorpha tetra and Mecidea major. Some upland gamebirds and granivorous songbirds are known to feed on the seeds of Bouteloua spp. (Grama Grasses), but information for Side Oats Grama in Illinois is unavailable. In Texas and states of the Great Plains, the McCown Longspur and Wild Turkey eat the seeds of various Grama grasses. Some hoofed mammalian herbivores, including bison, horses, and cattle, graze on Grama grasses readily, including Side Oats Grama. Photographic Location

More info for the terms: fire management, litter, mesic

Spring burning appears to be most beneficial to sideoats grama [4,6,88]. Site characteristics should be part of a fire management plan for sideoats grama. Fire is more beneficial in relatively humid, more productive grasslands than in drier, less productive sites, partially because litter buildup in more productive communities can reduce sideoats grama productivity, while litter improves moisture-holding capacity of soil in drier sites [114,163]. Studies indicate that sideoats grama generally increases after fire on relatively mesic prairie sites [25,53,190,199,228] but shows a short-term decrease following fire on more arid grasslands of the Southwest [1,21,33,220]. Burning every 4 to 5 years appears to benefit sideoats grama more than more frequent burning [38,175].

More info for the terms: cover, frequency, mesic

Site grazing and fire history is likely to affect the response of grasses
to fire. In an unfinished manuscript, Hulbert (as presented in Gibson [72])
specified 6 to 10 years of mowing and burning treatments are not sufficient
to remove all effects of prior burning and grazing, which may influence fire
behavior and effects on sideoats grama.

The response of sideoats grama to fire varies with time of burning. Several
studies report favorable response of sideoats grama to spring burning. Sideoats grama increased under
annual early spring burning of grassland pasture [6]. In Kansas bluestem prairie, Aldous
[4] studied response to several annual burning treatments conducted after rains, when
wet ground protected the root crowns of dominant grasses.
The number of sideoats grama plants doubled in 6 years under early spring
burning; increased under mid-spring burning; increased by more than a 3rd of
the original number of plants in the late spring-burned plot; but showed little
change on the fall-burned and unburned plots [4]. In Wisconsin late-spring fire enhanced flowering of sideoats
grama more than did an early spring fire, and resulted in a  greater
postfire increase in flowering on
the mesic site compared to the drier site. In the first 2 years of the
study, sideoats grama averaged a 250% increase in flowering after early spring burning and 600%
after late spring burning on dry-mesic plots. Increases in flowering on the dry
site were 60% and 150% for early and late spring burns, respectively [88]. McMurphy [134] compared percent basal cover

of sideoats grama on plots burned annually in March with those
burned in April or May, and with unburned plots, over 12 years. On
the "ordinary upland" site with medium- or loam-textured soil, the unburned pasture consistently had a lower
percent of sideoats grama than the burned plots, although the differences were only significant
(p<0.05) between unburned and early (March) burn sites, and not significant in all
years. There was no apparent trend between burned and unburned plots on the
limestone breaks site. On the claypan site, late spring (May) burned and early
(March) burned pastures supported significantly more (p<0.05) sideoats grama than the mid-spring
(April) and unburned plots. In contrast, Henderson [87] compared an unburned plot with
3 plots with 3 different fire treatments (late fall, early spring, and late spring burn),
and found no significant difference in frequency of occurrence of sideoats grama
among plots. The author specifies that due to the abundance of sideoats grama,
only dramatic declines would have been detected by the frequency of occurrence
data.
Sideoats grama increased following early spring burns in eastern Kansas [190]
and in southern Nebraska. The table below compares the herbage yield of sideoats
grama harvested in June and September from burned and mowed plots [199]:
Herbage yield (kg/ha) by
treatmentHarvest dateBurned (April 25, 1980)Mowed (September 1979 and 1980)ControlJune 19801528249September 1980155244160June 198119112316September 198170559274

More info for the terms: competition, cover, density, fire frequency, fire severity, fire suppression, frequency, graminoid, litter, mesic, natural, severity, wildfire

Sideoats grama recovers from burning by tillering and/or rhizomatous spread (in Bouteloua curtipendula var. curtipendula), and by establishing from seed [196]. Awnless seeds may be carried by wind [219] into burned areas for natural reestablishment, and the nutrient-rich postfire environment may encourage mass flowering in postfire year 2 or 3 [88].

The response of sideoats grama to fire varies with growth form, fire frequency and severity, season of burn, climatic conditions, and composition of associated plant community. Fire generally favors the bunchgrass variety, Bouteloua curtipendula var. caespitosa. The rhizomatous variety of sideoats grama (Bouteloua curtipendula var. curtipendula) generally decreases after fire, particularly in dry years. It may require 3 or more years for full recovery [228].  In wet years the rhizomatous variety tolerates fire "reasonably well" [227]. Several studies have documented the response of sideoats grama to fire. Results vary by study and are summarized below.

Sideoats grama appears to respond most favorably to fire at approximate 5-year intervals. In southeastern Arizona, Robinett and Barker [175] studied the response of several grass species in areas subjected to different fire frequencies during the hot season (May through July). Species composition on plots subjected to 1 fire, 2 or 3 fires, or 5 or 6 fires over 15 years was compared on sites with different soil textures and other site characteristics. On the Loamy Hills and Granitic Hills sites, sideoats grama had greatest percent cover relative to other species on plots that were burned 3 times over the 15-year period, compared to sites burned only once or those burned 5 or 6 times during that time. On the Sandy Loam Upland site, frequency of sideoats grama was approximately 40% on the 1-burn site and declined to less than 5% on sites subjected to 3 or 5 burns in the 15-year period. Decadence of sideoats grama was observed on sites burned only once. A similar trend in response of sideoats grama to different fire frequencies was reported by Collins and others [38] on the Konza Prairie in northeastern Kansas. Average cover of sideoats grama was highest (4.9%) in plots burned every 4 years, compared to 3.1% on plots burned annually and 1.6% on unburned ploys. However, sample sizes were small (n = 2 or n = 3) and significance of differences in cover of sideoats grama was not reported. Becker [13] found sideoats grama increased over 5 years on plots burned annually at low to moderate severity on a blue grama-little bluestem prairie in southwestern Minnesota.

Several studies indicate that site characteristics influence the response of sideoats grama to fire. In the Molino Basin of southern Arizona, Caprio [35] compared vegetation on unburned sites with sites burned in June 1983. He found cover of sideoats grama increased following burning on south and east slopes, but declined on the north slope. Fire severity was not specified. Pemble and others [164] reported flowering of sideoats grama was stimulated by fire on a dry, hilly, undisturbed prairie site, inhibited on a mesic, level, undisturbed site, and showed no significant increase or decrease (p > 0.05) on a mesic, gently sloping to level  site. Litter was almost completely consumed on dry hilly site, but considerable litter remained in depressions on the wetter sites. Fire severity was not specified. In 1937, Leopold [123] compared vegetation of Mexico and the United States. He concluded that the Sierra Madre of Chihuahua, Mexico, supported comparatively lush stands of sideoats grama because of frequent fires and light grazing. Across the border, fire suppression and overgrazing had already reduced sideoats grama cover in the United States by that time.

Fire response of sideoats grama is partially dependent on the response of competing species. Cover of sideoats grama decreased after burning treatments on a big bluestem-porcupine grass (Hesperostipa spartea) tallgrass prairie in Iowa. The site had been mowed prior to the experiment, allowing sideoats grama to maintain an artificially high cover. After burning without follow-up mowing, the tall grasses provided more competition. In contrast, sideoats grama increased or remained essentially the same on a loess hills prairie site [25]. On a tallgrass prairie site in Kansas, stem density of sideoats grama was reduced after 3 years without burning on both deep- shallow-soil plots [53].

Burning prior to seeding can help establishment of sideoats grama. When used for revegetating stands dominated by exotic Lehmann lovegrass (Eragrostis lehmanniana), sideoats grama had higher seedling density after seeding on a burned plot than on plots sprayed with herbicide prior to seeding, although the difference among plots was only significant (p<0.05) for the late-season (August) planting in 1 year [18]. Reseeding of prescribed burned areas resulted in "especially good establishment" of sideoats grama in Great Basin shrubsteppe area of northwestern Arizona [19].

Several studies, most from the southwestern United States, have found a short-term decrease in sideoats grama after burning. Cover of sideoats grama "decreased dramatically" after a wildfire in a desert mountain scrub community in Texas, determined by comparing vegetation on burned and unburned plots at postfire year 2 [33]. Frequency of sideoats grama was less on 3-year-old burns than on unburned sites in the Guadalupe Mountains of New Mexico. Fire severity was not specified, but fuels were estimated at < 0.5 ton/acre for litter and cured grasses and 7 tons/acre for living vegetation [1]. On Arizona range sites sideoats grama often declines in the season or year immediately following burning but recovers in subsequent years [21,220]. This fire response was documented in an extensive of body of research on fire effects in semidesert grassland, oak savanna, and Madrean oak woodlands of southeastern Arizona. See the Research Project Summary of Bock and Bock's [21] work for more information on burning conditions, fires, and fire effects on more than 100 species of herbaceous and woody plants, birds, small mammals, and grasshoppers.

In some cases burning may have little or no effect on sideoats grama. In a study in Wind Cave National Park, South Dakota, Bock and Bock [22] measured plant height of several graminoid species before and after burning with "relatively cool" surface fires. Height of sideoats grama did not differ significantly (p < 0.05) in any year between burned and unburned control plots. Sideoats grama showed no difference in flowering response between burned and unburned stands in Wisconsin [51]. Fire severity was not specified, but the 2.3-inch (5.8-cm) mulch layer was completely removed by the fire.

Fire can increase nutritional value of sideoats grama. Iron, phosphorus, and zinc concentration in sideoats grama increased with increasing fire frequency, although trends in nutrient increase were not all statistically analyzed. The effects of fire frequency on nutrient concentrations in sideoats grama are summarized in the table below [158]:

Nutrient Concentrations Consecutive years burned 0 1 2 3 4 K (%) 0.58 0.56 0.57 0.58 0.59 Ca (%) 0.36 0.29 0.34 0.3 0.34 Mg (%) 0.13 0.13 0.14 0.14 0.15 P (%) 0.05 0.10 0.10 0.08 0.08 Total N (%) 0.50 0.54 0.52 0.50 0.55 Zn (ppm) 17.9 23.0 25.0 26.1 25.0 Cu (ppm) 1.3 1.3 1.2 1.1 1.3 Fe (ppm) 22.9 25.5 29.4 33.7 38.9 Mn (ppm) 18.6 19.2 21.0 19.5 19.2

For more information about the nutritional value of sideoats grama, see Management Considerations.

More info for the term: culm

The immediate effect of fire on sideoats grama varies seasonally with differences in air temperature and plant desiccation. A study in Arizona indicated that lethal temperatures at culm bases of sensitive perennial grasses such as sideoats grama closely approximate existing air temperatures at or near ground level during hot dry months of summer. During cooler, moister periods, when plant material is less desiccated, lethal temperatures at culm bases are much higher. Over the 2-year study, the lethal temperatures for sideoats grama ranged from 138 to 154 degrees Fahrenheit (58.8-73.7 °C) [98].

Fire generally top-kills sideoats grama [227]. Further information concerning the immediate effects of fire on sideoats grama is sparse.

More info for the terms: graminoid, initial off-site colonizer, rhizome, secondary colonizer, tussock

POSTFIRE REGENERATION STRATEGY [191]:
Rhizomatous herb, rhizome in soil
Tussock graminoid
Initial off-site colonizer (off-site, initial community)
Secondary colonizer (on-site or off-site seed sources)

More info for the terms: frequency, stand-replacement fire, wildfire

Fire adaptations: Sideoats grama establishes after fire through seed and/or lateral spread by rhizomes and tillers. Recovery often takes 2 to 3 years [227,228] and varies with site conditions, burning frequency, and plant growth form (see Fire Effects). Sideoats grama fruits lack an awn; therefore, initial seed dispersal onto burned sites is effected primarily by wind. Postfire seed production may increase after burning. In Wisconsin, flowering of sideoats grama increased after spring burns [88] (see Fire Effects). However, another Wisconsin study found no increase in flowering of sideoats grama after an April wildfire [51] .

FIRE REGIMES: Grassland and shrubland ecosystems where sideoats grama is important historically experienced frequent, stand-replacement fire. FIRE REGIMES are highly variable across sideoats grama's wide distributional range, however. In plains grassland communities where sideoats grama is important, historic fire return intervals ranged from less than 10 years up to 35 years. Return fire intervals for desert grassland communities with sideoats grama ranged from 1 to 100 years, and some shrub-dominated communities with sideoats grama had historic fire return intervals of 100+ years [163]. FIRE REGIMES for plant communities and ecosystems in which sideoats grama occurs are summarized in the table below. For further information regarding FIRE REGIMES and fire ecology of communities where sideoats grama is found, refer to the 'Fire Ecology and Adaptations' section of the FEIS species summaries for the community and ecosystem dominants listed below.

Community or Ecosystem Dominant Species Fire Return Interval Range (years) bluestem prairie Andropogon gerardii var. gerardii-Schizachyrium scoparium < 10 [114,163] Nebraska sandhills prairie A. gerardii var. paucipilus-S. scoparium < 10 bluestem-Sacahuista prairie A. littoralis-Spartina spartinae < 10 desert grasslands Bouteloua eriopoda and/or Pleuraphis mutica 5-100 plains grasslands Bouteloua spp. < 35 [163] blue grama-needle-and-thread grass-western wheatgrass B. gracilis-Hesperostipa comata-Pascopyrum smithii 163,180,229] blue grama-buffalo grass B. gracilis-Buchloe dactyloides < 35 grama-galleta steppe Bouteloua gracilis-Pleuraphis jamesii < 35 to < 100 blue grama-tobosa prairie B. gracilis-P. mutica < 35 to < 100 mountain-mahogany-Gambel oak scrub Cercocarpus ledifolius-Quercus gambelii < 35 to < 100 juniper-oak savanna Juniperus ashei-Q. virginiana < 35 Ashe juniper J. ashei < 35 cedar glades J. virginiana 3-7 pinyon-juniper Pinus-Juniperus spp. 163] Colorado pinyon P. edulis 10-400+ [64,75,106,163] interior ponderosa pine* P. ponderosa var. scopulorum 2-30 [9,10,121] mesquite Prosopis glandulosa 135,163] mesquite-buffalo grass P. glandulosa-Buchloe dactyloides < 35 Texas savanna P. glandulosa var. glandulosa 163] oak-hickory Quercus-Carya spp. 210] oak-juniper woodland (Southwest) Quercus-Juniperus spp. 163] bur oak Q. macrocarpa 210] oak savanna Q. macrocarpa/Andropogon gerardii-Schizachyrium scoparium 2-14 [163,210] shinnery Q. mohriana < 35 little bluestem-grama prairie S. scoparium-Bouteloua spp. < 35 [163] *fire return interval varies widely; trends in variation are noted in the species summary

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More info for the terms: climax, codominant, cover, rhizome, secondary colonizer, succession

Sideoats grama occurs in all stages of succession. It is moderately shade tolerant [186], growing in partial shade to full sun [36,136,183,212]. In ponderosa pine woodlands of northwestern Nebraska, the importance of sideoats grama relative to other grass species increases with increasing canopy cover, indicating that sideoats grama is relatively shade tolerant [202]. Bolander [24] found sideoats grama in Arizona chaparral was moderately dense where the canopy was open and grazing was not been heavy. 

Sideoats grama can be a primary or secondary colonizer on burned areas. Seeds are carried into burned sites by wind or produced by plants surviving fire [88]. Sideoats grama occurs in early seral postfire communities [163] and increases on disturbed sites through asexual regeneration or self-seeding [210,213]. Sideoats grama seeds more successfully on burned than unburned sites [18,19], indicating it colonizes after disturbance by fire. It may increase in cover immediately following fire [134,190], indicating it can also spread by tillering or rhizome expansion. Leopold [123] described sideoats grama communities maintained by frequent fires in areas relatively undisturbed by grazing.

Sideoats grama is a climax indicator in arid grasslands throughout the Southwest [163], and is a dominant or codominant species in late-seral vegetation across much of the Great Plains [78]. Dodd and Holtz [52] list sideoats grama as a dominant component in late-seral grassland vegetation on a loam range site in southern Texas.

More info for the terms: apomixis, caespitose, cover, density, forb, perfect, warm-season

Sideoats grama regenerates from seed, rhizomes, and tillering [196].

Breeding system: Sideoats grama reproduces apomictically or sexually [49]. Apomixis occurs in the southern range of sideoats grama, most commonly within the range of Bouteloua curtipendula var. caespitosa. Sideoats grama has perfect flowers [78] that cross pollinate [76].

Pollination: In plants reproducing sexually, cross pollination is effected by wind [219].

Seed production: Sideoats grama produces a "fair amount of seed of rather low viability" [205] but seeds readily when adequate moisture is available [214]. There are several cultivars of sideoats grama (see Management Considerations) with varying seed productivity.

Seed dispersal: Awnless fruits suggest that sideoats grama seed is dispersed mainly by wind [49].

Seed banking: Little direct information is available about seed banking of sideoats grama, but several studies indicate that seed banking of sideoats grama is minor, and varies with local conditions. A study of seed banks in postsettlement vegetation communities in the Loess Hills of Iowa found sideoats grama had low seed density (<25 seeds/m2) in the seed bank of a shrubland site dominated by shrubby roughleaf dogwood (Cornus drummondii) and elm (Ulmus spp.), but moderate seed density (25-100 seeds/m2) in a grassland site dominated by Kentucky bluegrass (Poa pratensis) and smooth brome (Bromus inermis) [178]. Seeds of sideoats grama were not encountered in the seed bank of a deciduous woodland site dominated by tree-size roughleaf dogwood and elm. Examination of Texas seed banks in plots managed with long-term (36-year) grazing Texas revealed seeds of sideoats grama appeared to be transient and were not stored in seed banks. Sideoats grama was part of the historic vegetation: savanna dominated by caespitose mid-grasses including sideoats grama, Texas tussockgrass (Nassella leucotricha), Texas cupgrass (Eriochloa sericea), and little bluestem, with associated short grasses including curlymesquite (Hilaria belangeri) and hairy woolygrass (Erioneuron pilosum), and scattered clumps or individuals of oak (Quercus spp.) and Ashe juniper [108]. Sideoats grama's cover was not specified, although the authors did state late-seral mid-grasses had been reduced by grazing. In a study testing seed viability in Kansas prairie communities, soil samples taken from a mid-grass community dominated by sideoats grama yielded only 2 sideoats grama germinants [124].

Seed dormancy can affect timing of germination. Germination rate of sideoats grama seed from 148 sources ranged from 18% for the most dormant seed to 96% for the least dormant [126]. Major and Wright [126] found after the postharvest period, dormancy was completely broken in sideoats grama seed when floral parts were removed from caryopses. Germination was highest for seed with the heaviest caryopses, and fewer caryopses per gram. Dormancy may be controlled by "coumarin-like" inhibitory compounds.

Germination: A number of studies have focused on germination requirements of sideoats grama. These studies reveal that germination rates of sideoats grama vary with place of seed origin, as well as with temperature regimes, moisture, and other conditions. Sideoats grama seed vigor is good compared to seeds of other warm-season grasses [212]. When conditions are favorable, germination is rapid; in 1 case sideoats grama showed 50% germination within 22 hours [188]. Studies have found differing results  for germination success rate. Halinar [79] reported germination rates of 20 to 30% and 18 to 34% in 2 consecutive years. Other sources found 50 to 70% germination [40,68]. Jordan and Haferkamp [103] found high sideoats grama germination success, ranking 3rd out of 19 warm-season grasses tested. Wasser [212] stated most sideoats grama seed germinates within 7 days under ideal field conditions. Light improves germination [40]. 

Heat affects rate and success of sideoats grama germination. Temperatures between 50 and 86 degrees Fahrenheit (10 and 30 °C) are generally best for germination [68,181]. Sabo and others [181] found a constant temperature of 73 degrees Fahrenheit (23 °C), or alternating temperatures of 54 degrees Fahrenheit (12 °C) for 8 hours with 88 degrees Fahrenheit (31 °C) for 16 hours, gave best germination of sideoats grama. Over 1 month, germination of seed collected in southeastern Montana averaged 95% for treatments of 68 to 86 degrees Fahrenheit (20 to 30 °C). Seeds required 1 to 3 days to achieve 50% germination. Germination for the low-temperature treatment of 50 degrees Fahrenheit (10 °C) was only 60%, and seeds required 15 days to attain 50% germination [59]. Jordan and Haferkamp [103] found the minimum germination temperature for the 'NM-28' cultivar was 48 degrees Fahrenheit (8.9 °C).

Planting depth also affects germination rate. Sideoats grama had the highest germination rate (58%) at 1-inch planting depth compared to 37% at 0.5 inch (12.7 mm), 10% at 2 inches, and 0% at 3 inches (76 mm) [28]. Germination of sideoats grama is good under both dry and moist conditions [155]. Germination of sideoats grama is "not greatly affected" by water stress down to 1 mP [181]. Qi and Redmann [168], however, found sideoats grama had a lower tolerance to water stress than was reported in Sabo and others [181], with 1 of the lowest germination rates of the 6 grass species tested  under water stress. 

Seedling establishment/growth: Seedling vigor of sideoats grama is good to excellent [86,212]. In a study comparing seedling growth, sideoats grama seedlings developed more quickly than most of the 44 prairie forb and grass species tested [155]. In the  greenhouse, tillering began 3 weeks after seeds of sideoats grama were planted, and continued at a rapid rate [144]. Nine-week-old plants produced 20 to 40 stems and rhizomes. Temperature affected seedling growth rate. Seedlings grew more rapidly at 80 to 85 degrees Fahrenheit (26.7 to 29.4 °C) than at 60 to 65 degrees Fahrenheit (15.5 to 18.3 °C) [177]. Of 5 grass species tested for growth patterns, 'Coronado' sideoats grama showed the most rapid shoot and root growth [47].

Sideoats grama seedlings are more drought tolerant than many other warm-season grasses, although seedlings that are not well established can be killed by a short drought period [65]. Dahl and others [44] found sideoats grama was 1 of the easiest species to establish in wet or dry years in Texas. Root length and root:shoot ratio are important factors in survival rates of seedlings growing in water-limited areas [188]. In a study by Simanton and Jordan [188], sideoats grama had the highest root length, shoot length, and root:shoot ratio compared to other warm-season grass species. Robocker and others [177] reported sideoats grama has high root growth in relation to leaf development.

Asexual regeneration: Sideoats grama reproduces asexually from rhizomes and tillers. Rhizomes are the main form of reproduction in Bouteloua curtipendula var. curtipendula [205].  The bunchgrass variety of sideoats grama (Bouteloua curtipendula var. caespitosa) reproduces asexually from tillers. Although rhizomatous, vegetative expansion of the 'El Reno' cultivar of sideoats grama studied in Colorado was primarily from tillering. Rhizomes did not contribute significantly to new shoot production. According to Sims and others [189] the 'El Reno' cultivar produced rhizomes mainly from reproductive shoots and tillers mainly from vegetative shoots.

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More info for the terms: geophyte, hemicryptophyte

RAUNKIAER [170] LIFE FORM:
Hemicryptophyte
Geophyte

More info for the term: graminoid

Graminoid

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More info for the terms: formation, natural, phenology, root crown, warm-season

Sideoats grama starts growth in mid-spring, and generally flowers between July and September [212]. In native tallgrass prairie in central Oklahoma, anthesis occurs from July to September, seedlings sprout in November and December and in March and April, and seed formation and dissemination occur from July through November [2]. The growing period for sideoats grama in the southern Great Plains is April through October [182]. In Wisconsin, root crown growth occurred from early April through mid-July, then again from early to mid-August. Production of secondary and tertiary shoots occurred from mid-March through late October, and anthesis occurred from mid-July to mid-August [148]. Production of shoots slowed during flower production but did not cease at any time during the growing season. In general, sideoats grama flowers from April to October [105]. Flowering dates for sideoats grama vary with location, and are summarized in the following table:

Location Beginning of Flowering End of flowering OK June July [173] IL, VA, WV, CO, WY July September [142,193,226] CA April October [145] NM May October [128]
Phenology differs due to variety and place of origin. Olson [160] planted 4 cultivars of sideoats grama, and cultivars of other warm-season grasses, in a common garden in Minnesota to study phenology of grasses collected from locations throughout the Great Plains. Sideoats grams cultivars from North Dakota ('Kildeer') and South Dakota ('Pierre') reached anthesis 21 to 28 days earlier than cultivars from Kansas ('Butte' and 'Trailway'). In clones grown from locations throughout the Great Plains, flowering began earliest in plants from northern and western sites, and occurred progressively later in plants originating in more southward and eastward sites [133]. Flowering for northern clones was in late June, with the earliest flowering in clones from northeastern Montana. A study by Olmsted [159] also provides insight on the phenological variability of sideoats grama from different locations. Olmsted tested the photoperiodic response of sideoats grama from Texas, Oklahoma, and North Dakota. He found the Texas strain grew and flowered vigorously in natural or simulated 13-hour daylight. The Oklahoma strain flowered equally well and rapidly with 13 to 14 hours of daylight, and the North Dakota strain grew and flowered vigorously in 14- and 15-hour photoperiods. The photoperiodic responses of the strains corresponded to flowering earlier in the year and during longer days for more northern species, which may have been an adaptation in response to northward expansion of sideoats grama in the past.

The following is a representative barcode sequence, the centroid of all available sequences for this species.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 5
Specimens with Barcodes: 6
Species With Barcodes: 1

Sideoats grama has a global rank of G5, indicating it is demonstrably secure globally, but may be quite rare in parts of its range [129]. State and province protection status for sideoats grama is given below.

Location Rank Rank Key Connecticut Endangered Species in danger of extinction throughout all or a significant portion of its range, and with less than 5 occurrences in the state [39]. Kentucky Species of special concern Taxon should be monitored because is exists in a limited geographical area; may become threatened or endangered due to habitat destruction or biological or other factors; or is thought to be rare or declining but insufficient evidence exists to list it as endangered or threatened [107]. Maryland S2 State rare or vulnerable to extirpation. Typically 6 to 20 occurrences or few remaining individuals or acres [129]. Michigan S1/S2 S1: Critically imperiled in the state because of extreme rarity (5 or fewer occurrences or very few remaining individuals or acres). S2: Imperiled in state because of rarity (6 to 20 occurrences or few remaining individuals or acres) or because of some factors making it very vulnerable to extirpation from the state [138]. Mississippi S3/S4 S3: Rare or uncommon in state (21 to 100 occurrences). S4: Apparently secure in state [141]. New Jersey Endangered Species in danger of extinction throughout all or a significant portion of its range [152]. New York S1, Endangered Critically imperiled because of rarity ( 5 or fewer sites or very few remaining individuals) or extremely vulnerable to extirpation from the state due to biological factors [216]. Pennsylvania S2 Imperiled in the state because of rarity or because of some factor(s) making it very vulnerable to extirpation from the state. Typically 6 to 20 occurrences [138]. West Virginia S3 May be somewhat vulnerable to extirpation (20 to 100 documented occurrences) [218] Manitoba S2 Rare and may be vulnerable to extirpation [172].

Sideoats grama is the state grass of Texas [199].

Canada

Rounded National Status Rank: N3 - Vulnerable

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Widespread and common throughout much of North America.

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).

Comments: Some low-level threats from lack of disturbance/succession (glades may be fire-dependent) and from competition with exotics (Southern Appalachian Species Viability Project 2002).

Grasshoppers can be destructive of seedling stands. Some stem and leaf rust occurs in wet years and Mankin (1969) found several leaf spot and root rot fungi occurred on side-oats grama.

More info for the terms: association, competition, cover, forbs, frequency, litter, mesic, shrubs, tree

Herbicides and fertilizer treatments:
Reaction of sideoats grama to
herbicide treatments varies with the herbicide and stage of phenological development. Sideoats grama had good to
excellent tolerance to imazethapyr
applied either pre- or postemergence [14]. Application of 2,4-D favored establishment of sideoats grama
on an upland site seeded with native grasses and treated with 2,4-D, atrazine, and mowing
[26]. In a study of the effects of clopyralid, picloram,
triclopyr, and 2,4,5-T, development of sideoats grama seedlings was reduced as
rate of herbicide application increased [95]. Clopyralid had minimal effect at
application rates of 0.98 lb/ac (1.1kg/ha) and less, but the other 3 herbicides caused
more damage as application rate increased. Triclopyr and 2,4,5-T
had detrimental effects at 0.98 lb/ac (1.1kg/ha) or higher, and picloram caused increasingly
negative effects on growth at 1.96 lb/ac (2.2 kg/ha) and higher.
Application of fertilizer
may increase sideoats grama production. Application of nitrogen and nitrogen+phosphorus fertilizer increased
herbage production of sideoats grama
relative to the control on 3 different soil types in which laboratory
specimens were grown [99]. On a loamy upland site in south-central New Mexico, cover of sideoats grama increased over
4 years with annual June application of nitrogen [57].
Competition:
Light competition from trees may have detrimental effects on
sideoats grama stands. Sideoats grama increased after cabling of Colorado pinyon-oneseed
juniper woodland in south-central New Mexico [183]. After trees, shrubs, and forbs in another pinyon-juniper
woodland were killed, herbage production for sideoats grama increased from 5 kg/ha 1 year after
treatment to 155 kg/ha 3 years after treatment [36]. In eastern Nebraska native
little bluestem prairie, cover
of sideoats grama was lowest in shaded
plots under eastern redcedar, compared to plots
in open sites and at the edge of tree crowns [71]. In contrast, McPherson and
Wright [136] found cover of sideoats grama increased
with increased canopy cover of redberry juniper on
both ungrazed and formerly grazed sites, even though overall grass production
decreased with greater canopy cover. In another study sideoats grama increased on plots where redberry
juniper was controlled with picloram [176].
Sideoats grama can reduce the success of other species. Sideoats grama in dense stands may reduce
honey mesquite (Prosopis glandulosa) seedling
establishment [34]. Sideoats grama reduced dry mass of honey mesquite
when the 2 species were planted at the same time or when sideoats grama was already
established. Similarly, sideoats grama caused a decrease in the dry weight of
smooth hawthorn (Crataegus
laevigata) and sweet acacia (Acacia smallii) when planted with
those species [208].
Extracts from Utah juniper foliage and litter suppress growth of sideoats grama seedlings [100].
In grasslands, sideoats grama may be reduced by competition from taller prairie grasses more
adapted to mesic sites, declining in cover or disappearing from mesic
sites within a few years [46]. Sideoats grama may have lower yield where planted with
tallgrass species, as taller grasses can outcompete sideoats grama [130].
Response to grazing pressure:
Sideoats grama is often considered an
increaser under grazing [6,90,113,162]; however, sideoats
grama often decreases under grazing on arid western ranges [20,24]. Tomanek and Albertson [203]
report sideoats grama both
decreased and increased under grazing, depending on site characteristics and
grazing pressure. Sideoats grama often increases under grazing in tallgrass
prairies [90,162]. When growing in association with little bluestem and blue
grama, sideoats grama often increases with
heavy grazing pressure but may be replaced
by blue grama or forbs [102]. In Nebraska sideoats
grama increases under heavy grazing on favorable, wetter sites, but
does not do well under prolonged heavy grazing [194]. Sideoats grama may increase under grazing due to
reduced competition by other
grasses. Percent species composition of sideoats grama declined from 11.54% to 1.12%
after 17 years of protection from grazing on a mixed-grass prairie in Nebraska
[146]. On native prairie site in Kansas, a decrease in competition due to
drought caused an increase in relative cover and
seed production of sideoats grama until other grasses recovered [41]. Sideoats
grama is most abundant on
steep slopes not easily accessible to cattle, and is increasing on some western
ranges protected from grazing [20,67]. Bolander [24] states sideoats grama
is common in areas of Arizona chaparral that have not been overgrazed, but is
replaced by other grasses in heavily grazed areas. Similarly, cover of sideoats grama in semiarid grasslands
of the Edwards Plateau in Texas has been
reduced by prolonged overgrazing [109].
Fire affects the response of sideoats grama to grazing. Sideoats grama increased in early spring-burned pastures
where fire essentially eliminated Kentucky bluegrass (Poa pratensis), increasing grazing
pressure on sideoats grama [162]. Sideoats grama increased in cover and frequency in response to
bison grazing at stocking rates of 9 ha/AU to 5 ha/AU [85]; the difference between grazed and ungrazed plots was significant (p < 0.1) on
tallgrass prairie sites burned every 4 years but was not significant on plots
burned annually. On season-long grazed sites, moderately stocked (3.3 ac/head)
with cattle, sideoats grama represented a greater proportion of vegetation composition on
spring-burned plots than on unburned plots monitored from
1950 to 1967 [119]. Sideoats grama significantly (p< 0.05) increased in percent
species composition 4 years after fire on sites under season-long
continuous grazing and fertilized with 80 lb/ac (90 kg/ha) nitrogen, but decreased
(though change not significant at p = 0.05) on unburned, grazed plots fertilized at 80 lb/ac nitrogen [119]. For more information about the response of sideoats grama to
fire, see Fire Effects.
Several studies have investigated the effects of grazing and mowing on
sideoats grama [139,161,171]. Clipping reduces aboveground and belowground dry
mass [139], and can increase stands of sideoats grama if clipped herbage is
removed from the ground [161]. Clipping sideoats grama at a high
frequency and a high intensity (to 3 inches (8 cm) every 3 weeks) severely reduced
plant vigor compared to lighter, less frequent clipping (to 6 inches (15 cm) every 6
weeks) [171]. Reardon and others [171] caution against using clipping
as a direct surrogate for studying grazing response, reporting that regrowth
of sideoats grama was greater after grazing by domestic sheep, goats , or cattle than clipping to the
same height as grazed plants.

Contact your local Natural Resources Conservation Service (formerly Soil Conservation Service) office for more information. Look in the phone book under ”United States Government”. The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”

‘Butte’ was selected at Nebraska AES, Lincoln, USDA-ARS and SCS cooperatively by E.C. Conard and L.C. Newell. It represents native collections from Holt and Platte Counties in Nebraska that were combined and tested as Nebraska 37. Repeated field plantings revealed superior germination and establishment characteristics when compared with other sources.

‘El Reno’ was released cooperatively in 1944 by the SCS, Manhattan, Kansas Plant Materials Center and Kansas AES. The original seed was collected in a field location near El Reno, Oklahoma in 1934. The material was outstanding for leafiness, forage production and vigor. It also ranked well for disease resistance, seed production, and winter hardiness. It is widely used in range seedings and is adapted to Kansas, Oklahoma and northern Texas.

‘Haskell’ was released in 1983 by the James E. “Bud” Smith Plant Materials Center, Texas AES and USDA-ARS. The seed for this release was originally collected in 1960 by J.C. Yeary, Jr. in Haskell, Texas.

It was selected based on rhizome production and adaptation as far south as the Rio Grande Valley in Texas. It is also known for its high forage palatability and prolific seed production.

Killdeer was informally released in the late 1960’s by the Bismarck Plant Materials Center in Bismarck, ND. It is composed of seed collected from native stands in 1956 near Bowman, Bowman County and Killdeer, Dunn County, North Dakota. Killdeer possesses outstanding vigor, leafiness, fair seed production, freedom from disease and persistence in a cold, semi-arid environment.

‘Niner’ was released in 1984 by SCS and the New Mexico and Colorado AES. The original seed for the release was collected by G.C. Niner and J.A. Anderson in 1957 west of Socorro, New Mexico. Niner was a bulk increase of the collection made by Niner and Anderson.

Pierre was informally released in 1961 by the Bismarck Plant Materials Center and the South Dakota AES. The original seed for the release was collected in 1954 in Stanley County west of Pierre, South Dakota. The release is described as outstanding in vigor, leafiness, freedom from disease, seedling vigor and persistence in a semi-arid environment.

‘Premier’ was released in 1960 cooperatively by Texas AES and USDA-ARS and NRCS. The original seed was collected in 1953 from a single plant growing between Cuauhtemoc and Chichuahua, Mexico. The release is described as having good seedling vigor, good seed yield, drought tolerance, upright growth form and leafiness.

‘Trailway’ was cooperatively released in 1958 by Nebraska AES and USDA-ARS. The original seed was collected in 1953 in northern Holt County by L.C. Newell. The release is described as winter hardy, long lived, late maturing with a somewhat indeterminate heading and flowering response. Requires most of the growing season to mature a crop in eastern Nebraska and may fail to produce seed in areas with a shorter growing season.

‘Vaughn’ was released in 1940 by the New Mexico AES and SCS Plant Science Division. The original seed was collected from native stands in 1935 near Vaughn, New Mexico. The release is described as slightly variable, but all have erect leaves, good seedling vigor and easy to establish.

Northern, Central and Southern Iowa Germplasms were released in 1995 as source identified releases, by the Elsberry Plant Materials Center, University of Northern Iowa, Iowa Department of Transportation, Iowa Crop Improvement Association and NRVC. They are all composite lines from collections made in Northern, Central and Southern Iowa.

Seed production experiments conducted in Nebraska in the 1950’s found that side-oats grama response to nitrogen fertilization was dependent on moisture conditions during critical growth periods (Newell et al., 1962). Seed yields measured as whole spikes were substantially increased over unfertilized check plots by all rates of nitrogen applied. Under drought conditions the application of 60 and 90 pounds of nitrogen yielded whole spike yields of approximately equal amounts. Under favorable moisture conditions nitrogen fertilization improved the quality of the caryopsis by increased weight per 1000 caryopsis over unfertilized plots.

Seed of side-oats grama normally found on the open market consists of either whole spikes or individual florets, or mixtures of these, which vary widely in their content of germinable caryopsis. Thus, seeding rates of side-oats must be computed on the basis of purity and viability of the seed lot. Purity analysis of side-oats can be complicated by the inclusion of adhering glumes and spike fragments as part of the seed unit. As long as the seed unit has a germinable caryopsis in the spike it is considered viable and used in the computation of pure live seed by the seed analyst. Thus a spike may contain several germinable caryopses, but is counted only as one for the purpose of germination percentage.

The effect of burning on seed yield was studied by Newell etal. (1962) in fertilized and unfertilized plots. Although the seed yield results were numerically larger from both levels of fertilized plots when burned, the differences could not be proven to be statistically different. This finding is noteworthy since it proves that proper burning, if not conducted too late in the spring, does not reduce seed yield. Burning is a proven method of cleaning the field for the new seed crop year. Burning has also been known to help control cool season weeds and reduce disease inoculums for the new crop.

Thus, side-oats grama may be grown for seed in cultivated rows, and will respond to timely fertilization and irrigation applications.

As a mid-grass, side-oats grama is intermediate in many respects between the tall and short grass species. Side-oats grama is not as resistant to grazing

pressure as is blue grama due to its taller growth habit. Side-oats seedlings are vigorous and stands tend to establish quickly and can often be utilized for forage production the second year after planting. Side-oats grama is usually included in range mixes and should be managed as native rangeland. Management should include proper livestock stocking rates and correct season of use.

The preference is full sun and dry conditions. This grass grows readily in various kinds of soil, including those containing clay-loam, loess, gravel, rocky material, and sand. It is quite drought resistant and adapts well to gentle or moderate slopes.

Forage: Side-oats grama produces high quality, nutritious forage that is relished by all classes of livestock throughout the summer and fall, and it remains moderately palatable into winter. This makes it one of the most important range grass species.

Erosion Control: Weaver and Albertson (1944) described the role of side-oats grama in the recovery of grasslands following the drought of the 1930’s. It was one of the few grasses that covered large areas bared by the loss of other grasses during the drought period. Side-oats grama is recommended in grass mixtures for range and pasture seeding, for earth fill and bank stabilization, for other critical areas and recreational plantings. Successful seeding can be obtained in rocky, stony or shallow soil sites. In fact side-oats is often found in nearly pure stands on caliche outcrops, stony hillsides and breaks (Harlan, 1954).

Wildlife: Side-oats provides some forage for antelope and deer when actively growing. Elk will use this grass as forage throughout the year. Leithead et al. (1971) indicated that the seed of this species was consumed by wild turkeys.