Siskiyou kalmiopsis

Rhododendron leachianum L. F. Henderson, Rhodora 33: 205. 1931; Rhodothamnus leachianus (L. F. Henderson) H. F. Copeland

Shrubs, erect, rarely trailing, usually tufted, 2-4(-8) dm. Twigs pale reddish to purplish, becoming gray to dark gray, puberulent and sparsely stipitate-glandular, becoming glabrate. Leaves aromatic; petiole 0.5-2 mm, sparsely puberulent and sessile-glandular; blade dark green abaxially, light green adaxially, elliptic to elliptic-oblong, 10-25 × 5-12 mm, base cuneate, margins entire, usually plane, apex obtuse, usually apiculate, surfaces glabrous or sparsely sessile dotted-glandular abaxially, densely covered with sessile crystalline-punctate glands adaxially. Inflorescences erect, (5-)7-12(-15)-flowered; bracts leaflike. Pedicels 1-2 cm, hairy, glandular. Flowers: calyx lobes light purple, ovate, 3-5 mm, margins ± glandular-ciliate; corolla rose to deep pink, (12-)14-20 mm diam., petal ridges connected between corolla lobes, lobes connate ca. 1/2 their lengths, abaxial surface ± puberulent and glandular apically (throat puberulent or glabrous); filaments 3-7(-10) mm, rarely ciliate basally; anthers purple, oblong, 0.7-1.8 mm; style dimorphic, 7-10 mm (long form), 3-6 mm (short form); ovary puberulent, dotted-glandular. Seeds 0.3-0.7 mm. 2n = 24.

Flowering late spring-early summer. Open sunny ridges in xeric shrub community or sparse woodland, rooted in shallow or, more often, deeper soils, on a range of substrates, often including ultramafics; of conservation concern; (200-)600-1400 (-2100) m; Oreg.

Kalmiopsis leachiana is known from the Siskiyou Mountains in Curry and Josephine counties.