Hoary Phacelia - Phacelia incana
State Rank Reason (see State Rank above)
Phacelia incana occurs in Idaho, Nevada, Utah, Colorado and Montana. In Montana, it is known from approximately ten occurrences in Beaverhead County. It is difficult to estimate the size of populations because the plant is an annual, and seed germination varies greatly with climate. Habitat is probably not threatened by anthropogenic sources.
- Details on Status Ranking and Review
Score2 - Small: Generally 2,000-10,000 individuals.
Score1 - Peripheral, Disjunct or Sporadic Distribution in MT: Widespread species that is peripheral, disjunct or sporadically distributed within MT such that it occurs in <5% of the state (<7,500 sq. miles or the combined area of Beaverhead and Ravalli Counties) or is restricted to 4-5 sub-basins.
Area of Occupancy
Score2 - Low: Generally occurring in 4-10 Subwatersheds (6th Code HUC’s).
Score1 - Moderate: Species is restricted to a specific habitat that is more widely distributed or to several restricted habitats and is typically dependent upon relatively unaltered, good-quality habitat (C Values of 5-7).
Score0-1 - Stable to Minor Declines:
CommentTrends unknown, though populations are likely stable or experiencing only minor declines.
Score0-1 - Low to Medium.
Score1 - Moderate Vulnerability: Specific biological attributes, unusual life history characteristics or limited reproductive potential makes the species susceptible to extirpation from stochastic events or other adverse impacts to its habitat and slow to recover.
Raw Conservation Status Score
7 to 9 total points scored out of a possible 19.
Hoary Phacelia is an annual with erect, branched stems that are up to 10 cm high. The alternate leaves have well-developed petioles and broadly elliptic, entire-margined blades that are 3-15 mm long. The foliage is covered with spreading, often gland-tipped hairs. Short-stalked flowers are borne in sparse, narrow, 1-sided, curved spikes that unwind as they mature. The white to bluish flowers have 5 strap-shaped sepals that are 3-4 mm long and a 5-lobed tubular corolla that is scarcely longer than the calyx. Stamens are held within the tube. The fruit is a many-seeded capsule.
Flowering occurs in June-July and fruiting in July.
Other members of the genus Phacelia have lobed or divided leaves. Species of Cryptantha have bristly, hairy foliage and the foliage of Myosotis spp. lacks the gland-tipped hairs.
Occurs from eastern NV and central ID to southwestern MT, southern WY, northwestern CO, and western UT.
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
Hoary phacelia is found in stony, limestone-derived soil on steep talus slopes in the foothills. Associated vegetation is mountain mahogany (Cercocarpus ledifolius) with a sparse ground layer dominated by annuals such as Descurainia richardsonii, Collinsia parviflora and Cryptantha watsonii. Oryzopsis hymenoides and Agropyron spicatum are uncommon perennial grasses.
Ecological Systems Associated with this Species
Hoary phacelia is a small annual that completes its life cycle quickly. It occurs in sparsely vegetated, unstable habitats and probably benefits from disturbance. In dry years populations are composed primarily of seeds in the seed bank and are difficult to detect.POLLINATORS
The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus appositus
, Bombus bifarius
, Bombus centralis
, Bombus fervidus
, Bombus flavifrons
, Bombus frigidus
, Bombus huntii
, Bombus melanopygus
, Bombus mixtus
, Bombus nevadensis
, Bombus rufocinctus
, Bombus sylvicola
, Bombus sitkensis
, Bombus occidentalis
, Bombus griseocollis
, Bombus insularis
, and Bombus kirbiellus
(Macior 1974, Thorp et al. 1983, Shaw and Taylor 1986, Mayer et al. 2000, Wilson et al. 2010, Pyke et al. 2012, Koch et al. 2012, Williams et al. 2014).
Mule deer usually graze its habitat, and although livestock also have access, the steep slopes and dense, low canopy deter most cattle. Hoary phacelia is an annual, so grazing or moderate disturbance of any kind probably has a positive effect on population growth. Annual exotic weeds (Bromus tectorum and more recently Malcolmia africana) are increasing in its habitat.
Threats or Limiting Factors
STATE THREAT SCORE REASON
Threat impact not assigned because threats are not known (MTNHP Threat Assessment 2021).
- Literature Cited AboveLegend: View Online Publication
- Koch, J., J. Strange, and P. Williams. 2012. Bumble bees of the western United States. Washington, DC: USDA Forest Service, Pollinator Partnership. 143 p.
- Macior, L.M. 1974. Pollination ecology of the Front Range of the Colorado Rocky Mountains. Melanderia 15: 1-59.
- Mayer, D.F., E.R. Miliczky, B.F. Finnigan, and C.A. Johnson. 2000. The bee fauna (Hymenoptera: Apoidea) of southeastern Washington. Journal of the Entomological Society of British Columbia 97: 25-31.
- Pyke, G.H., D.W. Inouye, and J.D. Thomson. 2012. Local geographic distributions of bumble bees near Crested Butte, Colorado: competition and community structure revisited. Environmental Entomology 41(6): 1332-1349.
- Shaw, D.C. and R.J. Taylor.1986. Pollination ecology of an alpine fell-field community in the North Cascades. Northwest Science 60:21-31.
- Thorp, R.W., D.S. Horning, and L.L. Dunning. 1983. Bumble bees and cuckoo bumble bees of California (Hymenoptera: Apidae). Bulletin of the California Insect Survey 23:1-79.
- Williams, P., R. Thorp, L. Richardson, and S. Colla. 2014. Bumble Bees of North America. Princeton, NJ: Princeton University Press. 208 p.
- Wilson, J.S., L.E. Wilson, L.D. Loftis, and T. Griswold. 2010. The montane bee fauna of north central Washington, USA, with floral associations. Western North American Naturalist 70(2): 198-207.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Heidel, B.L. and J. Vanderhorst. 1996. Sensitive plant species surveys in the Butte District, Beaverhead and Madison Counties. Unpublished report to the Bureau of Land Management. Montana Natural Heritage Program, Helena, Montana.
- Lesica, P., K. Lackschewitz, J. Pierce, S. Gregory and M. O'Brien. 1986. Noteworthy collections: Montana. Madrono 33:310-312.
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Vanderhorst, J.P. and P. Lesica. 1995a. Sensitive plant survey of the Tendoy Mountains in the Beaverhead National Forest, Beaverhead County, Montana. Unpublished report to the Bureau of Land Management, Butte District. Montana Natural Heritage Program, Helena, MT. 59 pp. plus appendices.