Douglasia idahoensis

Douglass M. Henderson

Brittonia 33: 52, fig. 1. 1981 ,.

Common names: Idaho dwarf primrose
Treatment appears in FNA Volume 8. Treatment on page 266. Mentioned on page 264.

Plants loosely cespitose mats with branched caudex. Stems prostrate to ascending, with terminal, green leaf rosettes. Leaves erect, reflexed in age, succulent; blade oblong to oblanceolate, 7–10 × 1–2 mm, margins entire, apex acute or obtuse, surfaces puberulent, glabrescent, hairs simple. Scapes 1–6 mm, elongating little in fruit, hairy, hairs simple and forked. Inflorescences 2–7-flowered, bracteate; bracts 5–9, lanceolate to ovate-lanceolate, 2.5–0.7 × 0.7–1.2 mm, with scattered, simple hairs. Pedicels 3–7 mm. Flowers: calyx 4–7 × 2 mm, with simple hairs; corolla pink to magenta with yellow throat, limb 10–12 mm diam., lobes 3–6 × 4 mm, margins emarginate or entire. 2n = 36.

Phenology: Flowering mid summer.
Habitat: Gravelly soils, subalpine
Elevation: 2000-3000 m


Douglasia idahoensis is known only from a narrow region of northern Idaho. Its fleshy leaves and multiflowered inflorescence are distinctive. Morphologically and geographically, it is closest to D. laevigata; molecular genetic analyses show a closer relationship to D. montana. The single chromosome count of n = 18 for this species is somewhat questionable because it represents an anomaly for the genus, which typically has a base number of 19; this count should be verified.

Selected References


Lower Taxa