WYOMING’S
 

Threatened and Endangered 

Plant Species
 

Desert Yellowhead
 

Bureau of Land Management 

BLM
 

low slopes or 

erosional 

fans below 

sandstone 

mesas. 

Associated 

species include 

Indian ricegrass 

(Achnatherum 

hymenoides) 

and a suite of 

matted cushion 

plants and lowgrowing forbs, 

including several 

(Payson’s 

beardtongue, 

Devil’s Gate 

twinpod, 

cryptantha) that are also 

Conservation 

conservation strategy in 

and other federal agencies to 

Desert yellowhead grows one 

or more new shoots each year 

from an overwintering 

moisture is available. 

Studies suggest that insect 

pollination is necessary 

for development of ripe 

fruits and seed. Desert 

knows how long Desert 

yellowhead plants can 

live. Long term monitoring studies have shown 

that population numbers 

fluctuate from year to year, possibly due to variation in survival 

to adulthood or effects of proDesert YellowheaD Despite extensive tubular, tiny, and also bright yellow. 10,000 individual plants or clussearching of suitable habitat Desert yellowhead does not produce ters of stems (the exact size of Desert yellowhead (Yermo throughout the state for several showy, petal-like ray flowers along underground rootstalks is poorly xanthocephalus) is the rarest years, Desert yellowhead the outer rim of the flower head. known) have been counted in of Wyoming’s four listed remains known only from After being pollinated, the five disk peak years. threatened or endangered Dorn’s original population, florets comprising each flower head 

saw the plants in the spring surrounding the 

Species Act. An 

population. Dorn first area of 360 acres 

Rim area of Fremont sporting a tuft of white bristles to Desert yellowhead is restricted central Wyoming and 

located in the Beaver ripen into single-seeded fruits, each habitat 

a single location in 

plants, being known from 

County, Wyo. In aid in dispersal by the wind. Some to aridic sandstone and limestone nowhere else. 2002, the Desert botanists believe the bright yellow soils with high concentrations

What in the yellowhead floral bracts help attract bees for of volcanic ash derived from 

world is a Desert was listed as pollination in the absence of showier the Split Rock Formation.

yellowhead? threatened by ray florets. Populations occur mostly in

Nobody knew the U.S. Fish wind-carved deflation hollows

until 1990, when life historY and Wildlife and on barren 

Wyoming plant Service under 

expert Robert Dorn the Endangered 

discovered the first 

taproot. It begins 

flowering in late while conducting a survey population was designated June and contin- Rim phlox, and Caespitose the conservation needs of this of another rare plant species and as critical habitat in 2004. 

ues to flower over plant. The goal is to foster long suspected the plant might be a the entire growing restricted to barren habitats in term viability of the Desert new species of milkweed based DesCription 

season if adequate central and southern Wyoming. yellowhead and avert potential on its leathery leaves and waxy, Desert yellowhead is a taprooted threats that include oil, gas, and yellow buds. When he returned perennial with one to five leafy water development, powerline to collect a flowering specimen in stems up to 12 inches tall. The construction, off-road vehicle June, Dorn was surprised to learn alternate leaves are somewhat The Endangered Species Act defines 

that the mystery plant was actually succulent and leathery and either a threatened species as one that is use, livestock grazing, and plant 

a member of the sunflower family smooth or slightly toothed along likely to become in danger of collection. 

yellowhead seeds (Asteraceae or Compositae) and not the margins. Leaf blades are extinction within the foresee- The BLM recognizes that can germinate the a milkweed at all! Although the oval to lance-shaped, 11⁄2 to 10 same year that able future throughout all or plant conservation and protection flowers resembled those of Indian inches long, and often folded at a significant portion of its they form, is essential to sustain ecological, plantain (a genus of swampland the midvein. range. Federal law prohibits but some economic, and aesthetic values plants from the eastern U.S.), the the removal or destruction Typical plants have 25 to overwinter of our public lands. The BLM, floral bracts were quite unusual of threatened plants on any federal 200 flower heads crowded at the top to germinate in partnership with local, state, in being bright yellow rather land or as a result of federal actions. of the stem. Like other members the following and federal agencies, works to than green and leafy as in 99% Desert yellowhead also receives of the sunflower family, Desert year. No one achieve its multiple-use mandate of all other composites. Dorn protection under the BLM’s special yellowhead flowers are located on of public land management. For recognized that he had not only a status species management policy. a small disk that is surrounded by new species, but also a new and two decades, the BLM has worked 

undescribed genus. The plant was a series of modified leaves called The Wyoming BLM is with the Wyoming Natural Diversity 

floral bracts or phyllaries. Desert preparing a Desert yellowhead given the scientific name Yermo Database and the Rocky Mountain yellowhead is unique among xanthocephalus by Dorn in 1991; Herbarium at the University of Wyoming composites in having coordination with local, state, yermo meaning “desert” in Spanish, Wyoming to survey, monitor, and bright yellow floral bracts that and xanthocephalus translating as research native plant species in order resemble a series of fleshy bananas. apply federal statutes and agency “yellow head” for the prominent Beaver to maintain Wyoming’s native plants The actual flowers (or florets) are longed dormancy. More than policy in a way that addresses yellow bracts. and their habitats. 
 

 

 

 

 

 

 

 

 

Suggested Reading 

Dorn, R.D. 1991. Yermo xanthocephalus (Asteraceae: 

Senecioneae): a new genus and species from 

Wyoming. Madroño 38(3): 198-201. 

Fertig, W. 1995. Status report on Yermo 

xanthocephalus in central Wyoming. Prepared for 

the Bureau of Land Management. Wyoming 

Natural Diversity Database, Laramie, Wyo. 

Heidel, B. 2002. Status report on desert yellowhead 

(Yermo xanthocephalus) in Wyoming. Prepared for 

the Bureau of Land Management. Wyoming 

Natural Diversity Database, Laramie, Wyo. 

Milius, S. 1999. Unknown plants under our noses. 

Science News 155(1): 8-10. 

Scott, R.W. 2000. Field studies on Yermo 

xanthocephalus Dorn. Final report to Bureau of 

Land Management. Central Wyoming College, 

Riverton, Wyo. 

For more information contact: 

Bureau of Land Management 

(307) 775-6256 

U.S. Fish and Wildlife Service 

(307) 772-2374 

Wyoming Natural Diversity Database 

(307) 766-3020 

Citation: 

B. Heidel, W. Fertig, F. Blomquist, and 

T. Abbott. 2008. Wyoming’s Threatened and 

Endangered Species: Desert Yellowhead. 

Wyoming Bureau of Land Management, 

Cheyenne, Wyo. In collaboration with 

Wyoming Natural Diversity Database. 

Note: New data on the biology and status of 

this species are being collected constantly, and 

parts of the information in this publication may 

become outdated. The fact sheet provides a 

general overview of the status of this species 

and is not intended as the sole source of 

species information for planning and research 

purposes. For additional information on this or 

other threatened and endangered species, or for 

additional copies of this publication, refer to the 

suggested readings or contact the botany contacts 

of the Bureau of Land Management in Wyoming, 

U.S. Fish and Wildlife Service in Wyoming, and 

the Wyoming Natural Diversity Database. 

This Desert Yellowhead fact sheet is one in a series 

on Wyoming’s Threatened and Endangered Plant 

Species published by Bureau of Land Management 

and the Wyoming Natural Diversity Database. 

Front and back cover photo by Charmaine Delmatier 

Inset photo by B. Heidel 

Desert yellowhead illustration by Jane Dorn 

Reprinted with permission of Madroño 

BLM/WY/AE-09/008+1150