Twobristle Rockdaisy

Perennials or subshrubs, 2–12 cm; glabrate, glabrous, minutely hairy, or scabrous-hispidulous. Leaves: petioles (0–)1–7 mm; blades lanceolate, lance-ovate, ovate, or suborbiculate, 4–8 × 2–8 mm, margins entire, serrate, or shallow-lobed. Heads usually borne singly (often obscured by the dense leaves), 7–8(–10) × 3.5–7 mm. Peduncles 0–3 mm. Involucres narrowly campanulate. Phyllaries 8–10(–12), linear to broadly or narrowly lanceolate, 4.5–6 × 1–2 mm. Ray florets 0. Disc florets 11–17; corollas white, tubes 0.8–1 mm, throats tubular to subfunnelform, 1.5–3 mm, lobes 0.8–1 mm. Cypselae oblong to oblanceolate, 1.8–2.2(–2.5) mm, margins notably calloused, glabrous; pap-pi of 2–3(–5) ± flattened bristles 1.5–2.3 mm.

Laphamia bisetosa Torrey ex A. Gray, Smithsonian Contr. Knowl. 5(6): 106. 1853

Laphamia bisetosa Torr.; A. Gray, PI. Wright. 2: 106. 1853
A dwarf perennial with a thick woody caudex; stems many, about 3 cm. high, scabroushispidulous; leaves opposite and alternate, short-petioled ; blades about 5 mm. long, ovate or obovate, thick, entire or with 1 or 2 teeth, glandular-punctate; heads subsessile; involucre campanulate, 5 mm. high, 3 mm. broad; bracts 6-8, oblanceolate, ciliate at the apex; rays none; disk-flowers 6-8; corolla 4 mm. long; tube half as long as the cylindric throat; achenes oblong, puberulent ; pappus of 2 awns, shorter than the achene.
Type locality: Canon of the Rio Grande, below Presidio del Norte [on the label given as below Mt. Carmel, Rio Grande]. Distribution: Western Texas.