Asteraceae (tribe Heliantheae) subtribe Clappiinae
Phytologia 41: 39. 1978.
Subshrubs or shrubs, 5–40 cm (often succulent or fleshy). Leaves mostly cauline; opposite (proximal) or distally or mostly alternate; sessile; blades mostly linear to filiform (terete or subterete), margins entire, faces glabrous. Heads radiate, borne singly. Calyculi 0. Involucres hemispheric or obconic. Phyllaries persistent, 12–16 in 2–4+ series (distinct, obovate or ovate to lanceolate or linear, unequal, striate with resinous nerves in Clappia). Receptacles convex, usually epaleate (paleae rarely scattered, subulate scales; receptacles sometimes with setiform or subulate enations). Ray-florets 2–11 or 10–15, pistillate, fertile; corollas yellowish or yellow. Disc-florets 20–100+, bisexual, fertile; corollas yellowish or yellow, tubes shorter than to longer than funnelform throats, lobes 5, deltate to narrowly lanceovate; anther thecae pale; stigmatic papillae in 2 lines. Cypselae clavate to columnar (10–12-ribbed, sparsely hairy); pappi persistent, either of 12–25 subulate scales in 1 series, or of ca. 50 bristles or setiform scales in 3–4 series.
sw United States, Mexico
Genera 2, species 3 (2 genera, 3 species in the flora).
Traditionally, Clappia has been included in Helenieae and Pseudoclappia in Senecioneae. H. Robinson (1981) suggested that the two genera are related to Varilla (Varillinae).