Claytonia rosea

Claytonia rosea grow a small round tuber 20–100 mm in size with a corky or woody skin that is 5-10 mm thick to protect it. The stems can be 2–15 cm long, but are absent when the plant is not large enough to flower. When the plant is young it will have leaves that rise directly from the soil on individual leaf stems (basal leaves). These basal leaves are blade linear to narrowly spatulate, 1–7 cm long and 0.4–2 cm wide. This difference helps to distinguish them from Claytonia lanceolata with its wider leaves. When large enough to flower the basal leaves may be absent and instead there will be several cauline leaves, ones attached to the flowering stem, the same blade linear shape and 2–5 cm long. All of its leaves have a pointed end that may be slightly acute or obtuse.[5]

Claytonia rosea was scientifically described and named as a species by Per Axel Rydberg in 1904.[1] Though published by a highly respected botanist it was not well accepted as a species and was usually synonymized with Claytonia lanceolata.[8] In 1966 the botanist Ray J. Davis with Idaho State University published an article classifying it as Claytonia lanceolata var. rosea in the journal Brittonia.[9][10] However, in the same year Dianne K. Halleck and Delbert Wiens published an article setting forth an argument in favor of its status as a species. Their extensive field work showing distinctive chromosomal differences and reproductive isolation by ecological and seasonal differences was convincing.[8][11]

As of 2023 most authorities, including World Flora Online (WFO),[12] Plants of the World Online (POWO),[1] Flora of North America,[5], and the USDA Natural Resources Conservation Service PLANTS database (PLANTS)[3] recognize it as a valid species.

The chromosome number for Claytonia rosea is 16 in diploid individuals[5], and the species only rarely varies from this.[8]

Claytonia rosea is the earliest flower of spring in the foothills and montane forests. It It grows in small meadows, open hillsides, and mesas of montane ponderosa pine, Chihuahuan pine, and oak belts.[8][5]

The exact range of Claytonia rosea is uncertain with different authorities recording different areas. POWO records it in the four corner states of Colorado, Utah, New Mexico, and Arizona and the Mexican state of Coahuila.[1] PLANTS additionally records it as growing in Wyoming and Montana, but does not have information about distribution in Mexico.[3] FNA largely agrees with POWO, but also does not have specific information about what states in Mexico C. rosea grows in.[5]

NatureServe has assessed the global status of Claytonia rosea as "G4 - Apparently Secure", an uncommon but not rare species.[13]