Search / Plant Profile / Descurainia torulosa

Plant Profile

Wyoming Tansy-mustard (Descurainia torulosa)

Global Rank: G2 - Imperiled
Legal Status: N/A
Family: Brassicaceae
State: WY
Nature Serve ID: 156766
Lifeform: Forb/herb
Date Inducted in National Collection: 02/09/1992

Description:

Descurainia torulosa is a small multi-stemmed biennial or short lived perennial in the mustard family. Tiny yellow flowers grow from the stems' tips and bloom in June. In late July the plant produces linear, hairy fruits, 8-15 mm long. (Atwood 1994). The tansy mustard does not seem to tolerate competition or excessive exposure to the sun or wind and grows under slight overhangs or in small cavities in volcanic rock. However, it has been found on fully exposed habitats such as small ledges (Marriott 1991). The remaining known populations are scattered and extremely small making this species quite vulnerable (Dorn, 1989). There is much confusion about the status of this species. Prior to 1990 there were only four sites reported for this species in the world, all in Wyoming. When visited in 1989, one population was not relocated and another was determined to be a separate taxon.

Where is Wyoming Tansy-mustard (Descurainia torulosa) located in the wild?

Habitat:

This species is found growing on volcanic breccia, sandstone, and sparsely vegetated sandy slopes at base of N and NW facing cliffs at about 8,300-10,000 feet. This species has also been found in S to SW, E and N facing slopes, some growing under slight overhands, or in small cavities in the volcanic rock, others were in fully exposed habitat such as small ledges. (Marriott 1991)This species is associated with: Achillea millefolium (western yarrow), Erigeron compositus (cut-leaved daisy), and Oxyria digyna (mountain sorrel). (Dorn 1998)

Distribution:

Endemic to the Absaroka Mountains and Rock Springs Uplift in Wyoming (Fremont, Park, Sweetwater, and Teton Cos.). (Marriott 1991, 1992)

States & Provinces:

Wyoming Tansy-mustard can be found in Wyoming

Which CPC Partners conserve Wyoming Tansy-mustard (Descurainia torulosa)?

Denver Botanic Gardens

Not Sponsored

Assigned 06/09/17

CPC's Plant Sponsorship Program provides long term stewardship of rare plants in our National Collection. We are so grateful for all our donors who have made the Plant Sponsorship Program so successful. We are in the process of acknowledging all our wonderful plant sponsorship donors on our website. This is a work in progress and will be updated regularly.

Conservation Actions

09/08/2020

Additional seed collection needed.

09/08/2020

A limited taxonomic study has been done on this plant and members of the Descurainia genus, but further work is necessary (Marriott 1991).

Nature Serve Biotics

05/02/2017

Known only from the high volcanic mountains of the Absaroka Range (northwest Wyoming) and isolated buttes in the Great Divide Basin (Pine Butte; Lions Bluff in southwest Wyoming). Thirteen small occurrences have been documented and much suitable habitat has not yet been searched. Populations tend to be very small in area and number of individuals and may fluctuate greatly from year to year. The species is largely protected from human disturbance by its rugged habitat, but is vulnerable to extinction due to intrinsic habitat instability and natural population fluctuations.

Thomas Grant

01/01/2010

Threats include road building, drilling for oil and gas and natural disturbance such as rock fall and erosion (Marriott 1991).

Thomas Grant

01/01/2010

Six populations known, but one is presumed to be a separate taxon. (Marriott 1992)

Thomas Grant

01/01/2010

A limited taxonomic study has been done on this plant and members of the Descurainia genus, but further work is necessary (Marriott 1991).

Thomas Grant

01/01/2010

Found on Forest Service and Bureau of Land Management lands that are managed. (Fertig 2000)

Thomas Grant

01/01/2010

Taxonomic studies (lacking because of impoverished number of collections). Population monitoring is necessary.

Thomas Grant

01/01/2010

Additional seed collection needed.