Chaenactis carphoclinia var. carphoclinia
Plants (5–) 10–30 (–40) cm. Leaves basal (± withering) and cauline, longest 1–6 (–7) cm; petioles scarcely dilated proximally, ± herbaceous. 2n = 16.
Phenology: Flowering Jan–Jun.
Habitat: Open, rocky or gravelly (sometimes sandy) desert slopes and flats, shrublands
Elevation: -90–1900 m
Ariz., Calif., Nev., N.Mex., Utah, Mexico (Baja California), Mexico (Sonora)
Variety carphoclinia is one of the most abundant spring wildflowers in the Sonoran Desert; it extends to the southern Great Basin and northwestern Chihuahuan Desert. It is reported to be eaten by desert tortoises (Gopherus agassizii Cooper). Some stunted forms have been named var. attenuata; such forms recur in the most arid (or otherwise severe) habitats throughout the range of the species.
"longest" is not a number.