Ranunculus glaberrimus

Map courtesy of USDA, NRCS. 2013. The PLANTS Database. National Plant Data Team, Greensboro, NC. (2013, August 1).

Sagebrush buttercup is native to the United States and Canada. It occurs in portions of all the western United States east to Nebraska, the Dakotas [8,14,19,26,50], and from British Columbia [14,20] to southern Saskatchewan [42]. Elliptical buttercup is more widespread in the eastern areas of this distribution and may be the only variety that occurs in Colorado [23,48,49] and North Dakota [23,36]. Kartesz [23] considers the typical variety absent from Arizona, New Mexico, Colorado, Nebraska, Wyoming, North Dakota, Saskatchewan and Alberta. However, other floras do not describe such a restricted range for the typical variety. For instance, Munz and Keck [36] list the typical variety in New Mexico and Nebraska.

States and provinces [45]:
United States: AZ, CA, CO, ID, MT, ND, NE, NM, NV, OR, SD, UT, WA, WY
Canada: AB, BC, SK

Ranunculus glaberrimus Hook.:
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 terms: achene, forb, perfect

This description covers characteristics that may be relevant to fire ecology and is not meant for identification. Keys for identification are available (e.g., [14,18,19,20,23,33]).

Sagebrush buttercup is a perennial forb [4,18,26,50]. It typically grows 2 to 6 inches (5-15 cm) tall [19,44,46], but may grow to 10 inches (26 cm) tall [18]. The stems are erect to prostrate, 2 to 8 inches (5-20 cm) long [14,19], and do not root at the nodes [19,26,50]. Sagebrush buttercup has a cluster of fleshy [4,14,18,19,26], fibrous [4] roots 2 to 3 mm thick [14,19]. The mostly basal leaves are broad and rounded or ovate, with margins entire to lobed [14,19,20]. When present, the cauline leaves are generally dissected into 2 or 3 lobes [14,18,50]. The 5 sepals are commonly purplish-tinged [4,19,26]. The flowers occur singly, are 10 to 20 mm in diameter, and have 5 yellow petals [4]. Flowers in the Ranunculus genus are perfect [14,50]. Each sagebrush buttercup achene contains one seed [4]. From 30 to 180 achenes [4,14,19,50] occur in a semiglobose cluster at the top of the flower stalk. Achenes are slightly winged ventrally [14].

The main differences in appearance between the varieties are related to leaf shape [19,42]. Elliptical buttercup has entire, elliptic to oblanceolate basal leaves, while the typical variety has ovate to obovate, shallowly lobed basal leaves [14,17,19,26,33,48,50]. Variability between the 2 varieties makes distinguishing them difficult, especially in areas such as west-central Montana, where numerous transition forms occur [26].

Stems prostrate or ascending, 4-15 cm, glabrous, each with 1-4 flowers. Roots cylindric, 1-3 mm thick. Basal leaves persistent, blades reniform or obovate to very narrowly elliptic, 0.7-5.2 × 1-2 cm, base truncate, obtuse or attenuate, margins entire or with 3 broad, apical crenae, apex rounded to acute. Flowers: pedicels glabrous or nearly so; receptacle glabrous; sepals 5-8 × 3-7 mm, abaxially glabrous or sparsely pilose, hairs colorless; petals 5-10, 8-13 × 5-12 mm; nectary scale glabrous or ciliate. Heads of achenes globose, 7-12(-20) × 6-11(-20) mm; achenes 1.4-2.2 × 1.1-1.8 mm, usually finely pubescent; beak subulate or lance-subulate, straight or curved, 0.4-1 mm.

More info for the terms: fire regime, mesic

Sagebrush buttercup is fairly widespread throughout its range and occurs in a number of plant communities from low-elevation sagebrush  (Artemisia spp.)-grasslands to alpine meadows. Its elevation ranges from less than 900 feet (270 m) in California to over 10,000 feet (3,050 m) in Colorado and Wyoming [9]. See Table 1 for information on occurrence at varying elevations across its range.

Site characteristics: The 2 varieties seldom occur on the same site [19]. The typical variety grows on drier sites and at lower elevations [8]. In west-central Montana, the typical variety is most common in dry, open valleys and foothills [26]. Elliptical buttercup occurs in more montane areas [19,26].

Table 1: Elevational ranges of the 2 sagebrush buttercup varieties by state. Dashes mean no information is available for that location and/or variety. State General elevation Typical variety Elliptical buttercup California about 5,000 feet
(1,520 m) [36] 900 to 3,300 feet
(270-1,000 m) 900 to 3,500 feet
(270-1,070 m) [18] Colorado --- --- 5,000 to 10,000 feet
(1,520-3,050 m) [9,17] Montana --- 3,200 to 5,000 feet
(980-1,520 m) 3,200 to 9,000 feet
(980-2,740 m) [9] Nevada --- up to 5,500 feet
(1,680 m) 5,000 to 9,000 feet
(1,520-2,740 m) [24] New Mexico --- --- 7,000 to 8,500 feet
(2,130-2,590 m) [33] Utah 4,800 to 10,000 feet
(1,460-3,050 m) [50] 5,000 to 6,800 feet
(1,520-2,100 m) 5,500 to 9,000 feet
(1,680-2,750 m) Wyoming --- --- 6,600 to 11,600 feet
(2,010-3,540 m) [9]

Sagebrush buttercup grows on sandy [4,24,36] or loamy soils [8].Growth on clay is described as fair to good, and growth on gravel as fair to poor. Optimum soil depth is 20 inches (51 cm) or more [9]. In southern Alberta, sites with sagebrush buttercup had well-drained soils [4].

In New Mexico sagebrush buttercup was described as occurring on wet ground [33], and in southeastern Washington and adjacent Idaho it might be abundant in moist places in the early spring [47]. In southern Alberta, sites with sagebrush buttercup were mesic [4].

Plant communities: Sagebrush buttercup is common throughout many plant communities including open woodlands [41], shrublands [5,34], grasslands [4,5,6,34], and subalpine [41] and alpine [42] meadows. It is most often associated with ponderosa pine (Pinus ponderosa)[7,11,14,19,50] and sagebrush communities [5,18,19,20,24,31,36,48,50], including those dominated by Wyoming big sagebrush (Artemisia tridentata subsp. wyomingensis) [53] and mountain big sagebrush (Artemisia tridentata subsp. vaseyana) [13]. It is also present in woodland and forested communities comprised of fir and spruce (Abies-Picea spp.) [8], Douglas-fir (Pseudotsuga menziesia) [7,50], lodgepole pine (Pinus contorta) [39,50], juniper (Juniperus spp.) [19], or quaking aspen (Populus tremuloides) [31,48,50].

The typical variety most commonly grows in lowland valleys in sagebrush and grassland communities or in parklands or open woodlands, while elliptical buttercup generally occurs in higher-elevation communities [18,19,24,36] such as upland sagebrush [19,24,36], mountain meadows [24,36], and montane coniferous forests [36]. These forests may be dominated by ponderosa pine [19,24], juniper [19], Jeffrey pine (P. jeffreyi), fir, and/or spruce [8].

See the Fire Regime Table for a list of plant communities in which sagebrush buttercup may occur and information on the FIRE REGIMES associated with those communities.

Follow this link to the U.S. Forest Service Fire Effects Information Service to see a table with fire regime information that may be relevant to habitats in which this species occurs

Since data are lacking to date (2012), it would be ill-advised to make generalized conclusions regarding sagebrush buttercup's response to fire. Given that sagebrush buttercup typically begins growth before the beginning of the fire season throughout much of its range and that it may sprout following damage, negative impacts of fire on sagebrush buttercup are probably unlikely. Fires occurring in late winter or early spring, when sagebrush buttercup begins growth, could potentially have larger impacts than those that occur later in the year. Even if most or all sagebrush buttercups on a site are able to survive early spring fires, seed production may be impacted for at least the first postfire year.

More info for the terms: fire regime, wildfire

Sagebrush buttercup contributes little to fuels and is a component of communities with varied FIRE REGIMES.

FIRE REGIMES: Because sagebrush buttercup occurs in a variety of communities, it is subject to many different FIRE REGIMES ranging from surface fires every 8 to 10 years in some ponderosa pine woodlands to stand-replacement fires every few hundred years in certain lodgepole pine stands (see the Fire Regime Table). The fire seasons in these communities vary as well. Generally, the start of the fire season in the western United States occurs earlier than it did historically, primarily because of increased spring temperatures and earlier snow melts [3,51]. In 1970 the start of the first large wildfire (>1,000 acres (400 ha)) on Forest Service lands in the western states was in May. Since then, the first large fire has tended to occur earlier, with the first large wildfire in 2010 starting in March [3]. For information on FIRE REGIMES of communities were sagebrush buttercup occurs, see the Fire Regime Table and FEIS reviews of dominant species such as Pacific and interior ponderosa pines, Rocky Mountain lodgepole pine, Wyoming big sagebrush, and mountain big sagebrush.

More info for the terms: cover, forb, forbs, prescribed fire

Fire adaptations: Little is known about the adaptations of sagebrush buttercup to fire. It is known to sprout in response to disturbance [9,53]. Wrobleski [53] categorized sagebrush buttercup as a species that can "endure" fire.

Plant response to fire: Relatively little is known about the manner in which sagebrush buttercup responds to fire, but it likely sprouts from the roots after fire. Postfire establishment from seed is also possible, although to date (2012), no information on sagebrush buttercup's ability to establish from seed was available (see Regeneration Processes).

In a western Montana study, sagebrush buttercup was present on first-year burn plots in grassland communities, while absent from adjacent unburned plots [35]. It was listed as occurring in vegetation that develops after fire or clearcutting in lodgepole pine in southern Wyoming [31]. In a Wyoming big sagebrush site in central Oregon, cover of perennial forbs, including sagebrush buttercup, recovered to prefire levels by the 2nd year after a fall prescribed fire. Differences in perennial forb cover between burned and unburned control plots were not significant. Crude protein levels of perennial forbs on this site were significantly higher on the burned site than on the control in the 2nd postfire year (P=0.011) but not in later years [40].

More info for the terms: caudex, geophyte, initial off-site colonizer, root crown, secondary colonizer

POSTFIRE REGENERATION STRATEGY [43]:
Caudex or an herbaceous root crown, growing points in soil
Geophyte, growing points deep in soil
Possible:
Initial off-site colonizer (off site, initial community)
Secondary colonizer (on- or off-site seed sources)

Fire likely top-kills sagebrush buttercup. Because it flowers early in the year and disappears before midsummer [44], sagebrush buttercup is dormant when most fires occur in the plant communities it inhabits.

More info on this topic.

The communities sagebrush buttercup occurs in suggest that it prefers areas that are at least partially open (see Plant communities). In southeastern Washington and adjacent Idaho, sagebrush buttercup was more abundant in open areas than in dense mountain shrublands [47].

Sagebrush buttercup regenerates sexually through seeds and vegetatively through root sprouting [9] and division of mature plants [4]. Some species in the Ranunculus genus have seeds that are dispersed by ants [2], although whether this applies to sagebrush buttercup is unknown. Information on its ability to establish a seed bank was unknown as of 2012.

More info on this topic.

More info for the terms: chamaephyte, geophyte

Raunkiaer [38] life form:
Chamaephyte
Geophyte

More info for the term: forb

Forb

More info on this topic.

More info for the term: cool-season

  Lynne Robinson, www.rickandlynne.com

Sagebrush buttercup is a cool-season species that flowers in early spring [44,46,47,48,49]. It is the first flower of spring throughout most of its range. Flowering generally begins in March [29] or April, but the length of flowering is variable [9]. It has flowered as early as January near Reno, Nevada [8], and in west-central Montana [26]. Growth is generally completed by midsummer [44].

Timing of flowering may be influenced by weather conditions including temperature and snow fall the previous winter. Sagebrush buttercup was 1 of 8 species that exhibited earlier (P<0.017) flowering over the course of a study that ran from 1995 to 2008 [29], a period of increasing average temperatures (IPCC 2007b cited in [29]). The amount of snowfall in the previous January and December was negatively associated (P=0.007) with average first-flowering date of the 8 species. March temperatures were also significantly (P=0.021) associated with mean first-flowering date of the 8 species, with first-flowering increasing by 1.5 days with every 1 °C increase in temperature [29]. In a big sagebrush/bluebunch wheatgrass (Pseudoroegneria spicata) community in southern British Columbia, growth of sagebrush buttercup and 4 other spring ephemerals was completed 1 month earlier in a year with a dry April compared to the previous year, in which April precipitation was above average [37].

Information on state- and province-level protection status of plants in the United States and Canada is available at NatureServe.

Canada

Rounded National Status Rank: NNR - Unranked

United States

Rounded National Status Rank: NNR - Unranked

Rounded Global Status Rank: G5 - Secure

In a bluebunch wheatgrass mountain grassland of southeastern Washington, sagebrush buttercup occurred on 2 sites at intermediate levels of grazing, while it did not occur on the site that had been grazed most heavily or the site that was ungrazed for at least 27 years [6].