Howell's stitchwort

Arenaria howellii S. Watson, Proc. Amer. Acad. Arts 20: 354. 1885; Alsinopsis howellii (S. Watson) A. Heller

Plants annual. Taproots moder-ately stout. Stems erect to spread-ing, green, becoming purple, 12-30 cm, mostly glabrous, inter-nodes of all stems 2-7 times as long as leaves. Leaves sometimes overlapping prox-imally, often connate proximally, with loose, scarious to herbaceous sheath 0.2-0.5 mm; blade straight to recurved, green, becoming purple, concave, prominently 1(-3)-veined abaxially, linear-lanceolate, 5-15 × 1-2.5 mm, rigid, margins not thickened, slightly scarious, smooth, apex green to purple, obtuse to acute, often apiculate, flat to navicular, dull, densely stipitate-glandular; axillary leaves absent. Inflorescences 5-25+-flowered, open cymes; bracts lanceolate to ovate, herbaceous. Pedicels 0.3-4+ cm, stipitate-glandular. Flowers: hypanthium disc-shaped; sepals weakly veined proximally, ovate (herbaceous portion ovate to narrowly so), 1.9-3 mm, not enlarging in fruit, apex often purple, ± acute to acuminate, not hooded, stipitate-glandular proximally; petals oblanceolate, 1.8-2.3 times as long as sepals, apex rounded, entire. Capsules on stipe ca. 0.2 mm, broadly ovoid, 2.7-3.5 mm, usually longer than sepals. Seeds blackish brown, suborbiculate with radicle prolonged to rounded beak, somewhat compressed, 1.4-1.7 mm, tuberculate; tubercles low, rounded, often elongate.

Flowering spring-summer. Chaparral, Jeffrey pine-oak woodlands, serpentine; 500-1000 m; Calif., Oreg.