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Plant Profile

Howell's Spectacular Thelypody (Thelypodium howellii ssp. spectabilis)

The characteristic purple flowers with delicate white edging of Thelypodium howellii ssp. spectabilis. Photo Credit: Andrew Kratz

Global Rank: T1 - Critically Imperiled
Legal Status: Federally Threatened
Family: Brassicaceae
State: OR
Nature Serve ID: 156632
Lifeform: Forb/herb
Date Inducted in National Collection: 02/10/1987

Description:

Thelypodium howellii ssp. spectabilis is found only in five populations, all in the Baker-Powder River Valley region bordered by the Wallowa and Elkhorn Mountains in northeastern Oregon. This member of the mustard family is listed as Endangered by the State of Oregon and Threatened by the Federal Government. However, all known populations of this rare plant are found on private land. Unless a project or particular land use on private land involves federal funds or violates state law, neither listing does anything to protect this rare plant. At the very center of the population distribution, a yearly tradition continues to threaten this species. To prepare for the annual July 4-5 rodeo, a large field is mowed every year to provide parking. In 1998, observations were made before and after the rodeo (USFWS 1999). Before the rodeo, 10,000 individual plants were observed on the parcel. After the rodeo, only 300 remained, with most of them along the fence line. That year, like many, the mowing occurred at the height of their growing season when the plants still had immature fruit. Nearly the entire reproductive output of that population was destroyed by a single pass of the mower.

Where is Howell's Spectacular Thelypody (Thelypodium howellii ssp. spectabilis) located in the wild?

Habitat:

Thelypodium howellii ssp. spectabilis grows in low elevation (3,000 to 3,300 ft (1,000-1,100 m)) river valleys and moist (often alkaline) plains in the Baker-Powder River valley region of northeastern Oregon. In this area, winters are cold and summers are hot and dry. The annual precipitation averages 10.6 in (27 cm), most of which falls as snow. Associated species include Sarcobatus vermiculatus (greasewood), Elymus cinereus (giant wild rye), Spartina gracilis (alkali cordgrass), Poa juncifolia (alkali bluegrass) and Chenopodium spp.

Distribution:

OR: Baker-Powder River valley region (Baker Co., Union Co.)

States & Provinces:

Howell's Spectacular Thelypody can be found in Oregon

Which CPC Partners conserve Howell's Spectacular Thelypody (Thelypodium howellii ssp. spectabilis)?

Rae Selling Berry Seed Bank & Plant Conservation Program

Conservation Actions

09/30/2020

Research on seed production, inbreeding depression, seed germination, and cultivation requirements of Thelypodium howellii spp. spectabilis (Gisler, pers. comm.).

09/30/2020

Experimental re-introduction project using both seeds and transplants from the greenhouse (Gisler, pers. comm.).

09/30/2020

Germination trials conducted at The Berry Botanic Garden. Seeds were subjected to either 8 weeks of cold stratification or no cold stratification followed by either constant 68F (20C) or alternating 50/68F (10/20C). In one trial no seeds germinated. In another trial, 40% of seeds subjected to cold stratification followed by constant 68F temperatures germinated. No other treatment resulted in any germination. The seed had been stored for at least ten years. Trials are now being conducted with recently collected seed (BBG File).

09/30/2020

Seeds collected and stored in the Seed Bank at The Berry Botanic Garden.

09/30/2020

Seeds collected and stored in the Seed Bank at The Berry Botanic Garde

Nature Serve Biotics

05/02/2017

Thelypodium howellii ssp. spectabilis is a subspecies endemic to a small range in eastern Oregon. The taxon is known from twelve sites. Much of the historical habitat and formerly known populations have been destroyed; all remaining populations occur on private land.

Edward Guerrant, Ph.D.

01/01/2010

Threats, as stated by the U.S. Fish and Wildlife Service (USFWS 1999) and Meinke (1982) include: Habitat loss due to agricultural conversion. Habitat degradation due to grazing, agricultural conversion, and hydrological modifications. Plant destruct

Edward Guerrant, Ph.D.

01/01/2010

As of 1999: Fewer than 11 small sites comprising 5 populations. The total number of individuals varies greatly in response to environmental conditions (temperature, rainfall, etc). Recent surveys have revealed individual populations as small as 10 individuals to as many as 16,000. As of the last surveys, the total population appears to be around 30,000 (USFWS 1999).

Edward Guerrant, Ph.D.

01/01/2010

Research on seed production, inbreeding depression, seed germination, and cultivation requirements of Thelypodium howellii spp. spectabilis (Gisler, pers. comm.). Experimental re-introduction project using both seeds and transplants from the greenhouse (Gisler, pers. comm.). Germination trials conducted at The Berry Botanic Garden. Seeds were subjected to either 8 weeks of cold stratification or no cold stratification followed by either constant 68F (20C) or alternating 50/68F (10/20C). In one trial no seeds germinated. In another trial, 40% of seeds subjected to cold stratification followed by constant 68F temperatures germinated. No other treatment resulted in any germination. The seed had been stored for at least ten years. Trials are now being conducted with recently collected seed (BBG File).

Edward Guerrant, Ph.D.

01/01/2010

Only two populations have ever been actively managed for the protection of Thelypodium howellii ssp. spectabilis. At the largest known site (not the greatest number of individuals) there was a conservation agreement between one landowner and the Oregon Department of Fish and Wildlife (ODFW). At another site, an agreement between the landowner and The Nature Conservancy recently expired (U.S. Fish and Wildlife Service, 1999). Listed Threatened by the Federal Government and listed Endangered by the State of Oregon. Portions of a few small sites occur on Oregon Department of Transportation (ODOT) right-of-ways. The department takes this rare plant into consideration when planning construction or mowing along the roads (USFWS 1999). Voluntary agreements between landowners and the U.S. Fish and Wildlife Service to limit grazing between April and July (USFWS 1999). A draft recovery plan is being developed (as of 2001). Seeds collected and stored in the Seed Bank at The Berry Botanic Garden.

Edward Guerrant, Ph.D.

01/01/2010

Study life history, growth requirements, and general ecology (USFWS 1999). Limit livestock grazing when plants are actively growing. Limit mowing when plants are actively growing.

Edward Guerrant, Ph.D.

01/01/2010

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