Chaenactis nevadensis

Perennials, 2–10(–12) cm (cespitose or ± matted); proximal indument ± thinning with age, whitish, lanuginose. Stems mostly 10–20+, decumbent to ± erect. Leaves ± basal, 2.5–5 cm; largest blades ovate to deltate, ± plane, (1–)2-pinnately lobed; primary lobes mostly 2–4 pairs, ± congested, ultimate lobes ± plane. Heads 1(–2) per stem. Peduncles mostly ascending to erect, (0.5–)3–11 cm. Involucres obconic to ± cylindric. Phyllaries: longest 9–12(–14) mm; outer stipitate-glandular, apices erect, ± rigid. Corollas 5.5–8 mm. Cypselae 5.5–7.5 mm; pappi: longest scales 3–5 mm. 2n = 12.

Phenology: Flowering Jul–mid Sep.
Habitat: Loose sandy or gravelly, mainly volcanic soils or scree (rarely on serpentine), openings in or above subalpine conifer forests
Elevation: 1900–3200 m

Calif., Nev.

Discussion

Chaenactis nevadensis is known mainly from the northern Sierra Nevada and southern Cascade Range (Shasta to Placer counties, California; Washoe County, Nevada). It was recently discovered disjunct on ultramafic rocks of Bully Choop Mountain west of Redding, California, where it approaches small forms of C. suffrutescens in habit (see discussion there). It is sometimes cultivated in rock-gardens and may be found beyond its native range. Chaenactis nevadensis and C. suffrutescens appear to be sister or ancestor-derivative species. I have seen no evidence to support reports that C. nevadensis intergrades with C. alpigena (P. Stockwell 1940, as C. nevadensis var. mainsiana), with C. douglasii var. alpina (M. Graf 1999), or with any other taxon.

Selected References

None.

Lower Taxa