Chrysothamnus viscidiflorus

More info for the term: shrubs

Green rabbitbrush is one of the most widely distributed shrubs on rangelands throughout western North America. It occurs from British Columbia south to southeastern California and east to North Dakota, Arizona, New Mexico and Texas.

Distribution by subspecies is as follows [10]:

Chrysothamnus viscidiflorus subsp. lanceolatus - southern British Columbia to northern New Mexico
Chrysothamnus viscidiflorus subsp. puberulus - Great Basin
Chrysothamnus viscidiflorus subsp. viscidiflorus - southern California and northern Arizona to northern Washington and western Montana eastward to northwestern Nebraska

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):

5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
12 Colorado Plateau

AZ CA CO ID MT NE NV NM ND OR
SD TX UT WA WY

BC SK

Chrysothamnus viscidiflorus (Hook.) Nutt.:
Canada (North America)
United States (North 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: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

More info for the term: shrub

Green rabbitbrush is a low native shrub growing from 1 to 3.6 feet (0.3-1.1 m) with many brittle, erect stems branching from a compact base [57]. The species has a large geographic range and wide ecological amplitude. Leaves are deciduous [89]. Disc flowers are borne in terminal cymes [16]. The main taproot is at least 1.9 feet deep (0.6 m), and many major secondary roots extend laterally [61]. Plants are relatively short lived (approximately 12-13 years). Their senescence and attrition from some densely populated stands on early successional sites is related to infestation by larvae of the beetle Acamaeodera pulchella. Where green rabbitbrush is scattered within late-seral big sagebrush stands, there is a lower level of infestation [98].

Shrubs, 10–120 cm; with woody, branched caudices, bark whitish tan, becoming gray, flaky and fibrous with age. Stems ascending, green, soon becoming tan, glabrous or puberulent, sometimes resin-dotted, often resinous. Leaves ascending, spreading, or deflexed; sessile; blades with evident midnerves plus sometimes 1–2 pairs of smaller, collateral nerves, linear to lanceolate, 10–75 × 0.5–10 mm, flat or sulcate, often twisted, margins often undulate, sometimes ciliate, apices acute to apiculate, faces glabrous or puberulent. Heads in dense, rounded cymiform arrays (to 7 cm wide), not overtopped by distal leaves. Involucres cylindric to obconic or campanulate, 4–7 × 1.5–2.5 mm. Phyllaries 12–24 in 3–5 series, in spirals or weak vertical ranks, mostly tan, green to brown subapical patch often present, midnerves usually evident (at least distally), linear-oblong, lanceolate to elliptic or obovate to spatulate, 1–5 × 0.5–1.2 mm, unequal, chartaceous, margins scarious, eciliate or ciliolate to erose-ciliolate, flat or convex, sometimes weakly keeled, apices acute to obtuse or rounded, sometimes apiculate, flat, faces glabrous or puberulent. Disc florets (3–)4–5(–14); corollas 3.5–6.5 mm, lobes 0.7–1.7 mm; style branches 2.2–3.2 mm (exserted beyond spreading corolla lobes), appendages 0.8–1.5 mm (length shorter than stigmatic portion). Cypselae tan to reddish brown, turbinate, 2.5–4.2 mm, ± 5-angled, moderately to densely hairy; pappi tan, 3.5–6 mm.

Crinitaria viscidiflora Hooker, Fl. Bor.-Amer. 2: 24. 1834

Chrysothamnus viscidiflorus subsp. lanceolatus grows with big sagebrush (Artemisia tridentata), snakeweed (Gutierrezia spp.), and other rabbitbrush (Chrysothamnus spp.). Chrysothamnus viscidiflorus
subsp. puberulus is most commonly found in big sagebrush communities with other subspecies of low rabbitbrush, as well as with salt-tolerant species such as halogeton (Halogeton glomeratus), shadscale (Atriplex confertifolia), and winterfat (Krascheninnikovia lanata). It is occasionally found with pinyon (Pinus spp.) and juniper (Juniperus spp.). Chrysothamnus viscidiflorus
subsp. viscidiflorus is most common in sagebrush (Artemisia spp.) and pinyon-juniper. It is associated with salt-tolerant shadscale, halogeton, and winterfat at lower elevations. Chrysothamnus viscidiflorus var. stenophyllus is usually found in sagebrush communities on poor soils and disturbed sites. It also grows in more saline areas.

Community classifications in which green rabbitbrush is described as a dominant species are as follows:

An ecological reconnaissance of the Artemisia steppe on the east central Owyhee uplands of Oregon [20]

Flora and major plant communities of the Ruby-East Humboldt Mountains with special emphasis on Lamoille Canyon [50]

Big sagebrush (Artemisia tridentata vaseyana) and longleaf snowberry (Symphoricarpos oreophilus) plant associations in northeastern Nevada [82]

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 term: shrub

104 Antelope bitterbrush-bluebunch wheatgrass
107 Western juniper/big sagebrush/bluebunch wheatgrass
210 Bitterbrush
212 Blackbush
302 Bluebunch wheatgrass-Sandberg bluegrass
303 Bluebunch wheatgrass-western wheatgrass
314 Big sagebrush-bluebunch wheatgrass
315 Big sagebrush-Idaho fescue
317 Bitterbrush-bluebunch wheatgrass
322 Curlleaf mountain-mahogany-bluebunch wheatgrass
324 Threetip sagebrush-Idaho fescue
401 Basin big sagebrush
402 Mountain big sagebrush
403 Wyoming big sagebrush
404 Threetip sagebrush
405 Black sagebrush
406 Low sagebrush
412 Juniper-pinyon woodland
414 Salt desert shrub
415 Curlleaf mountain-mahogany
421 Chokecherry-serviceberry-rose
501 Saltbush-greasewood
611 Blue grama-buffalo grass
612 Sagebrush-grass
615 Wheatgrass-saltgrass-grama
708 Bluestem-dropseed

More info on this topic.

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

K011 Western ponderosa forest
K012 Douglas-fir forest
K015 Western spruce-fir forest
K016 Eastern ponderosa forest
K017 Black Hills pine forest
K018 Pine-Douglas-fir forest
K019 Arizona pine forest
K021 Southwestern spruce-fir forest
K023 Juniper-pinyon woodland
K024 Juniper steppe woodland
K037 Mountain mahogany-oak scrub
K038 Great Basin sagebrush
K039 Blackbrush
K040 Saltbush-greasewood
K041 Creosotebush
K046 Desert; vegetation largely lacking
K051 Wheatgrass-bluegrass
K052 Alpine meadows and barren
K055 Sagebrush steppe
K056 Wheatgrass-needlegrass shrubsteppe
K057 Galleta-three-awn shrubsteppe
K063 Foothills prairie
K064 Grama-needlegrass-wheatgrass
K065 Grama-buffalo grass
K067 Wheatgrass-bluestem-needlegrass
K098 Northern floodplain forest

More info on this topic.

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):

FRES17 Elm-ash-cottonwood
FRES20 Douglas-fir
FRES21 Ponderosa pine
FRES23 Fir-spruce
FRES29 Sagebrush
FRES30 Desert shrub
FRES34 Chaparral-mountain shrub
FRES35 Pinyon-juniper

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):

210 Interior Douglas-fir
219 Limber pine
220 Rocky Mountain juniper
237 Interior ponderosa pine
238 Western juniper
239 Pinyon-juniper

It is well adapted to drought and occurs in desert or semi-desert environments [6,20]. Green rabbitbrush grows on open ridges, on slopes, and along drainageways [38]. It grows on dry, well-drained medium to coarse-textured soils and exhibits fair salt tolerance [46, 55,69]. Green rabbitbrush grows on alkaline soils and exhibits an affinity for calcium [53].

Subspecies overlap in range but have somewhat different ecological requirements [58]. Chrysothamnus viscidiflorus subsp. lanceolatus is fairly common in dry foothills and mountainous habitats. Chrysothamnus viscidiflorus subsp. puberulus generally occurs at lower elevations on dry plains, valleys, and foothills, particularly on poorer soils and in disturbed areas. Chrysothamnus viscidiflorus subsp. viscidiflorus grows on soils with a pH of 6.0 to 8.4 [10].

Green rabbitbrush is most commonly found at elevations between 2,600 and 11,000 feet (790 and 3,350 m) [37,90]. Elevational ranges for several subspecies are as follows [10]:

Chrysothamnus viscidiflorus subsp. lanceolatus 976 to 11,000 feet (297-2,590 m)
Chrysothamnus viscidiflorus subsp. puberulus 4,200 to 10,000 feet (1,280-13,48 m)
Chrysothamnus viscidiflorus subsp. viscidiflorus 850 to 12,800 feet (259-3,901 m)

More info for the terms: competition, cover, density, forbs, fuel

Green rabbitbrush produces small stems and seed stalks annually which die but remain on the plant for a year or more. During drought periods, this dry, dead material may increase fuel accumulation and contribute to the spread of fire [64].

The recovery of green rabbitbrush after fire depends on both its ability to resprout after fire and its production of large numbers of achenes when released from competition. To prevent massive reestablishment of green rabbitbrush, potential treatment sites should be chosen carefully. An adequate cover of perennial grasses and forbs reduces green rabbitbrush reproduction. In northern Nevada, a density of not less than 2.5 perennial grass plants/m2 is recommended [98].

More info for the terms: prescribed fire, restoration

Green rabbitbrush sprouts vigorously after fire [1,45,78]. Sprouts originate from epicormic buds located just below the soil surface [69]. Typically, a single shoot appears the first year after burning [91,99]. Green rabbitbrush also reestablishes rapidly through seeds which may be carried relatively long distances [1]. Response to fire could vary by subspecies [69].

Green rabbitbrush often increases on burned range sites [46]. Production may be reduced for 1 to 3 years after fire, but then increases rapidly [45,66]. Studies have documented a 4- to 9-fold increase in production within the first 20 years after fire in northeastern Idaho [37]. After fire near Dubois, Idaho, production was reduced by 59% in the first postfire year [95]. Three years after the fire, production had doubled relative to preburn levels. It had tripled at the end of 12 years [95].

Green rabbitbrush is relatively short lived and is eventually overtaken by reinvading sagebrush. In sagebrush-grass communities of Nevada, recovery of green rabbitbrush to preburn levels may occur within 20 to 25 years, with green rabbitbrush much reduced in 40- to 50-year-old stands [45,69].

The Research Project Summary Vegetation response to
restoration treatments in ponderosa pine-Douglas-fir forests of western Montana provides
information on prescribed fire and postfire response of plant community
species, including green rabbitbrush, that was not available when
this species review was written.

More info for the terms: density, forb

Green rabbitbrush sprouts vigorously after fire [1,45,78]. Sprouts originate from epicormic buds located just below the soil surface [69]. Typically, a single shoot appears the first year after burning [91,99]. Green rabbitbrush also reestablishes rapidly through seeds which may be carried relatively long distances [1]. Response to fire could vary by subspecies [69].

Green rabbitbrush often increases on burned range sites [46]. Production may be reduced for 1 to 3 years after fire, but then increases rapidly [45,66]. Studies have documented a 4- to 9-fold increase in production within the first 20 years after fire in northeastern Idaho [37]. After fire near Dubois, Idaho, production was reduced by 59% in the first postfire year [95]. Three years after the fire, production had doubled relative to prefire levels. It had tripled at the end of 12 years [95].

Fire may not always lead to increases in green rabbitbrush. Fall and spring prescribed fires in a basin big sagebrush community in east-central Oregon had no significant effect on green rabbitbrush density in postfire year 1 or 2 compared to density on control plots [102]. See the Research Project Summary of this study for more information on fire effects on green rabbitbrush and 60 additional woody plant, grass, and forb species.

Green rabbitbrush is relatively short lived and is eventually overtaken by reinvading sagebrush. In sagebrush-grass communities of Nevada, recovery of green rabbitbrush to prefire levels may occur within 20 to 25 years, with green rabbitbrush much reduced in 40- to 50-year-old stands [45,69].

More info for the terms: fire intensity, fuel, shrubs

The potential damage done to the plant is affected by the proximity of other shrubs, which provide additional fuel and higher fire intensity. With higher intensity or a longer burnout time, there is a greater chance of lethal heating of basal buds [101].

In sagebrush-grass communities of the Great Basin, burning during flowering when carbohydrate levels are at their lowest can be most deleterious to rabbitbrush species. If plants are defoliated by insects or browsing ungulates prior to burning they may lack sufficient reserves to resprout [69].

More info for the terms: fuel, fuel loading

Green rabbitbrush is usually top-killed by fire [45,54]. It has high resin content, and both foliage and stems may be consumed, even with relatively high moisture content. Fuel distribution as well as overall fuel loading affects the potential survival of green rabbitbrush [101].

More info for the terms: adventitious, initial off-site colonizer, shrub

Small shrub, adventitious bud/root crown
Initial off-site colonizer (off-site, initial community)

More info for the term: competition

Green rabbitbrush regenerates after fire by sprouting and by establishing from off-site seed.

Green rabbitbrush is commonly observed on burned sites in west-central Utah [12]. Burning temporarily eliminates big sagebrush and other plants that compete for resources such as water or space. Release from competition stimulates green rabbitbrush to produce large numbers of viable achenes that are widely dispersed by wind. Seedlings that emerge from these achenes establish successfully because of their rapid root elongation [59,60].

The range of fire intervals reported for some species that dominate communities where green rabbitbrush occurs are listed below. To learn more about the FIRE REGIMES in those communities refer to the FEIS summary for that species, under "Fire Ecology or Adaptations."

ponderosa pine (Pinus ponderosa): 2 to 42 years
Mexican pinyon (P. cembroides): 20 to 70 years

More info on this topic.

More info for the terms: climax, shrub

Green rabbitbrush quickly and aggressively invades disturbed open sites including burns and overgrazed rangelands [7,12,86,90]. It is a seral species in sagebrush communities and occupies disturbed areas such as burns after competing vegetation has been removed [28,29]. This shrub persists in small numbers in naturally disturbed areas such as washes, sand dunes, and talus slopes [100]. However, it attains dominance only on highly disturbed early seral sites [84]. Green rabbitbrush often remains dominant for the first 15 years after disturbance, but then declines and is replaced by species such as big sagebrush [90]. In a Nevada study, individual plants become senescent in about 12 years [101]. Longevity may vary with subspecies, however. Tueller and Payne [81] report that Chrysothamnus viscidiflorus var. latifolius persists for approximately 10 years. In pinyon-juniper communities, green rabbitbrush is considered an early to mid-seral species [43].

Green rabbitbrush may continue as a minor component in stands near or at climax condition [29]. Green rabbitbrush is much reduced in 40- to 50-year-old stands [45]. One reason for the limited longevity of some green rabbitbrush stands may be infestation by the larvae of Aemaeodera. Elimination of green rabbitbrush plants or reduction of vigor makes the site more susceptible to invasion by sagebrush or other late successional species.

More info for the term: litter

Green rabbitbrush produces an abundance of small, viable, plumed seeds [69,86]. Seeds are easily dispersed even long distances by wind [69]. A stratification period does not appear to be necessary but may speed germination. In eastern Oregon, seedlings established in grass and litter on the northeast sides of older rabbitbrush and sagebrush plants. They also established on north-facing slopes of small mounds or indentations made by animals. Seedling mortality in these sites was greater than 50% by June 12. Established seedlings do not persist unless late spring rains replenish soil moisture. Green rabbitbrush establishment during dry years is unlikely because seedling roots do not elongate deeply enough before surface moisture is depleted [59]. Seedlings do not appear to originate from seed banked in soil [98,99].

Green rabbitbrush resprouts vigorously [95].

More info on this topic.

More info for the term: phanerophyte

Phanerophyte

More info for the term: shrub

shrub

More info on this topic.

The phenological development of green rabbitbrush varies by elevation, climate, and infrataxa. Restricted vegetative growth begins in early spring, with a period of accelerated growth occurring in late spring. Vegetative growth levels off just before flowering [81].

Flowering usually begins in mid- to late summer [89]. Green rabbitbrush flowers during summer in all but the most extreme drought years [86]. Seed ripens from late fall to early winter [89]. Seeds generally begin sprouting in March and continue sprouting into June. The following table gives a generalized comparison of flowering development of various subspecies [24]:
Chrysothamnus viscidiflorus subsp. lanceolatus Begin Full End State Flowering Flowering Flowering --------------------------------------------------------- UT May Aug. Aug. CO June Aug. Sept. WY July July Sept. MT July Aug. Aug. Chrysothamnus viscidiflorus subsp. viscidiflorus Begin Full End State Flowering Flowering Flowering --------------------------------------------------------- WY July Aug. Aug. MT May Aug. Aug. Phenological development for Chrysothamnus viscidiflorus subsp. puberulus in Idaho was [15]: Leaf growth starts 4/13 Twig growth starts 5/24 Fl. buds visible 6/30 First bloom 7/27 Full bloom 8/18 Bloom over 9/8 Seed ripe 9/2 Dissemination over 10/10 Young and Evans [97] report that green rabbitbrush (Chrysothamnus viscidiflorus subsp. viscidiflorus) undergoes 2 phases of branch elongation between bud burst and flowering. A period of restricted growth in early spring is followed by accelerated growth in late spring and early summer.

No legal status

Canada

Rounded National Status Rank: NNR - Unranked

United States

Rounded National Status Rank: NNR - Unranked

Rounded Global Status Rank: G5 - Secure

Reasons: Throughout western North America in sagebrush and pinyon-juniper woodland communities; can be weedy.

More info for the terms: achene, competition, shrub

Green rabbitbrush is killed by various herbicides, but control is difficult. For best control, the soil should be moist within 4 inches (10 cm) of the surface [63]. Detailed information on response to herbicides is available [26,49,81,90,92].

After a disturbance, there is a delay before green rabbitbrush reaches peak achene production in response to reduced competition. This is the appropriate time to conduct site rehabilitation if reduction of green rabbitbrush is a management objective. Seed and seedling production do not cease after the initial reproductive surge, but massive establishment will not occur if other species (especially perennial grasses) have already taken advantage of the site potential [98].

Green rabbitbrush is tolerant of grazing and may be "rejuvenated" by foliage removal [81]. In parts of the Great Basin, plants regrew rapidly after they were nearly completely consumed by spring-browsing black-tailed jackrabbits. There was no difference in biomass between browsed and unbrowsed plants by July [5]. Shrub control measures such as chaining may stimulate sprouting in green rabbitbrush [90]. Green rabbitbrush commonly increases on degraded rangelands as more palatable species are removed [16].