California rock jasmine

Androsace acuta Greene, Man. Bot. San Francisco, 238. 1894; A. asprella Greene; A. occidentalis Pursh var. acuta (Greene) Jepson; A. septentrionalis Linnaeus var. subulifera A. Gray

Plants annual, slender, not mat-forming. Leaves in single rosette; petiole absent; blade linear-lanceolate, 5-20 × 2-4 mm, base not narrowing to stem, margins ciliate, surfaces minutely hairy, hairs straight. Scapes usually 1, 2-8 cm, hairy to glabrescent. Inflorescences 2-6-flowered; involucral bracts ovate to lanceolate, relatively broad. Pedicels arcuate, slender, unequal, 0.6-6 cm. Flowers: calyx campanulate, without prominent ridges, 3-5 mm, lobes stiffly erect, subulate, apex prominently acute; corolla tube shorter than calyx, limb to 3 mm diam. Capsules slightly shorter than calyx, 2-5 mm. 2n = 40.

Flowering early-mid summer. Open, grassy slopes; 100-1200 m; Calif., Nev., Oreg.; Mexico (Baja California).

Androsace elongata occurs across Eurasia. Subspecies acuta is found only on the very western portion of North America and differs only slightly from European plants, primarily in its narrower calyx lobes. Androsace elongata in the broad sense is very similar to A. septentrionalis, differing primarily in leaf indumentum and higher chromosome number. Molecular analyses may determine if the California taxon represents a disjunct population of the Eurasiatic A. elongata complex or, more likely, is a variant of the North American A. septentrionalis or A. occidentalis showing morphology parallel to that of the Eurasian entity. Pending these analyses, the species is retained here under A. elongata.