Identity
Unique IDELEMENT_GLOBAL.2.821121
Element CodePDBRA0X0B0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderCapparales
FamilyBrassicaceae
GenusDescurainia
Concept ReferenceAl-Shehbaz, I.A. 2007. Descurainia kenheilii (Brassicaceae), A new species from the San Juan Mountains, Colorado. Harvard Papers in Botany 12(2): 395-396.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2022-09-22
Change Date2022-09-22
Edition Date2022-07-25
Edition AuthorsPanjabi, Susan Spackman (2011), rev. Treher (2021, 2022)
Threat ImpactUnknown
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences6 - 20
Rank ReasonsDescurainia kenheilii is endemic to southwestern Colorado (U.S.A.), where it is restricted to high elevations in San Juan Mountains. This inconspicuous, short-lived, perennial herb has an interesting story. It was described from a single depauperate specimen in 1997 and not relocated until 2021, when its description was revised and additional specimens were identified: moving this single site endemic to a regional endemic with 7-14 occurrences. The primary threat to this species is sheep grazing which browse related species of Descurainia. The species habitat may be impacted by climate change through increased shrubby growth or unfavorable climatic conditions.
Range Extent CommentsDescurainia kenheilii is endemic to southwestern Colorado (U.S.A.), where it occurs in the San Juan Mountains (Al-Shehbaz 2007). Rediscovery of this species in 2021 led to a better understanding of its morphology, as the type specimen was depauperate. In turn, knowledge of the distribution improved and expanded to potentially include Conejos, Hinsdale, Mineral, Rio Grande, and San Juan Counties (O'Kane and Heil 2022). This species is reported in error from Archuleta County (J. Ackerfield, pers. comm., 2021, I. Al-Shehbaz, pers. comm., 2021, Ackerfield 2015, FNA 2010). Descurainia kenheilii is likely endemic to high elevations in the San Juan Mountains, where Descurainia incana is found in the region at lower elevations, comparatively (O'Kane and Heil 2022). Range extent was calculated at 1,618 sq km based on specimens identified as D. kenheilii (O'Kane and Heil 2022).
Occurrences CommentsFor many years, this species was known only from a depauperate type specimen collected in 1997. In 2021, the species was rediscovered and description revised, leading to additional collections being annotated as Descurainia kenheilii (O'Kane and Heil 2022). There are now 14 element occurrences in the Colorado Natural Heritage Program database, however, 7 are based on specimens awaiting final verification of their identity. Five have not been observed in over 20 years (CNHP 2022).
Threat Impact CommentsThere is sheep grazing and recreational activities at the type location. Other species of Descurainia at the site are grazed (J. Ackerfield, pers. comm., 2021) and it is likely that Descurainia kenheilii would also be impacted by grazing. The impact of recreational activities is unknown, but it occurs near a gravel road used by off road vehicles (ORVs) and the Continental Divide National Scenic Trail. Alpine species may be particularly vulnerable to climate change which may result in increased shrubby growth or unfavorable climatic conditions.