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Plant Profile

Arrowleaf Thelypody (Thelypodium eucosmum)

A closeup of the unusual inflorescence of this species, shown here at Berry Botanic Gargen. Photo Credit: Ed Guerrant

Global Rank: G2 - Imperiled
Legal Status: N/A
Family: Brassicaceae
State: OR
Nature Serve ID: 154153
Lifeform: Forb/herb
Date Inducted in National Collection: 02/10/1987

Description:

When in full bloom, the beautiful pink-purple flowered inflorescences and arrow-shaped leaves of Thelypodium eucosmum create spectacular show. These tall and spindly members of the mustard family stand out against the otherwise brown and gray sagebrush-covered hillsides of eastern Oregon. This plant is known only from two counties in eastern Oregon, and is found only within the lower canyons of the Blue Mountains and along the tributaries of the John Day River. There are many populations, but population levels are highly influenced by fluctuating stream levels and yearly rainfall amounts.

Where is Arrowleaf Thelypody (Thelypodium eucosmum) located in the wild?

Habitat:

Lower to intermediate elevations in the juniper-sagebrush series of plant communities (Meinke 1982). Steep basalt drainages which are wet for part of the year, streambanks in full sun or shade, vernally moist alkaline areas, hillside seeps, and under isolated western juniper trees away from obvious moisture (BLM 2002). Associated species include western juniper (Juniperus occidentalis), Great Basin wildrye (Elymus cinereus), big sagebrush (Artemisia tridentata), and rattlesnake brome (Bromus brizaeformis) (BLM 2002).

Distribution:

OROR: Lower canyons of the Blue Mountains in Grant Co. and Wheeler Co.

States & Provinces:

Arrowleaf Thelypody can be found in Oregon

Which CPC Partners conserve Arrowleaf Thelypody (Thelypodium eucosmum)?

Rae Selling Berry Seed Bank & Plant Conservation Program

Not Sponsored

Conservation Actions

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

09/30/2020

Germination trials conducted at The Berry Botanic Garden. Plants were subjected to constant 20C temperatures or alternating 20/10C temperatures both with and without an 8 week cold stratification period. Seeds not subjected to the cold stratification did not germinate. Of the seeds subjected to the 8 weeks of cold stratification, those in the constant 20C chamber had 50% germination while those in the alternating 20/10C had 71% germinate (BBG file).

09/30/2020

Nature Serve Biotics

05/02/2017

Restricted to two counties in north-central Oregon. There are approximately 58 populations but many have less than 200 plants. Threats include grazing, flooding, irrigation projects, off-road vehicles, and mining.

Edward Guerrant, Ph.D.

01/01/2010

Threats, as stated by Halvorson (Halvorson, pers. comm. 2001), include the following: Most historical sites were probably extirpated by livestock grazing. Consequently, most of the known populations are in areas not normally grazed by livestock, or gra

Edward Guerrant, Ph.D.

01/01/2010

As of 2001: 55 populations on BLM land, 2 on National Forest land, and approx. 5 on private land. Populations range from 5 individuals to 5000, but vary greatly from year to year (ONHDB 2000).

Edward Guerrant, Ph.D.

01/01/2010

Germination trials conducted at Lewis and Clark College. Seeds were subjected to either a warm stratification 68F (20C) or a cold Stratification 41F (5C) for 6 weeks followed by either 59/41F (15C/5C) alternating temperatures or 68/50F (20C/10C) alternating temperatures. Seeds subjected to the warm stratification had very low germination (about 5%). Seeds subjected to 6 weeks of cold stratification germinated readily after being removed to the warmer germination chambers. Under alternating 59/41F (15C/5C) conditions, ~60% of the seeds germinated. Under alternating 68/50F (20C/10C) conditions, approximately 85% of the seeds germinated (Florance, pers. comm. 2001) Germination trials conducted at The Berry Botanic Garden. Plants were subjected to constant 20C temperatures or alternating 20/10C temperatures both with and without an 8 week cold stratification period. Seeds not subjected to the cold stratification did not germinate. Of the seeds subjected to the 8 weeks of cold stratification, those in the constant 20C chamber had 50% germination while those in the alternating 20/10C had 71% germinate (BBG file).

Edward Guerrant, Ph.D.

01/01/2010

50 of the 55 populations on BLM land are in active grazing allotments (Halvorson, pers. comm. 2001). One population was subjected to burning. Plants were robust the year after the fire, and two years of monitoring indicated that the population had fully recovered (Halvorson, pers. comm. 2001).

Edward Guerrant, Ph.D.

01/01/2010

Study effect of disturbances on Thelypodium eucosmum (Halvorson, pers. comm. 2001). Study soil moisture relationships (Halvorson, pers. comm. 2001).

Edward Guerrant, Ph.D.

01/01/2010

Collect and store seeds from across the range. Determine optimal germination conditions. Determine propagation and reintroduction protocols.