3. Gamochaeta purpurea (L.) Cabrera (purple cudweed, early cudweed)

Gnaphalium purpureum L.

Pl. 295 a–c; Map 1137

Plants usually with slender taproots, less commonly fibrous-rooted. Stems 7–45 cm long. Basal leaves present or sometimes withered by flowering time. Leaves 1–6(–8) cm long, oblanceolate to spatulate, the upper ones sometimes linear, strongly bicolorous, the upper surface sparsely woolly or with patches of cobwebby hairs, sometimes appearing nearly glabrous, the undersurface densely woolly, most or all of the hairs with a minute, swollen or expanded, transparent basal cell (requires 10× magnification to observe). Involucre 4.0–4.5 mm long, the outermost bracts ovate-triangular with sharply pointed tips, the innermost lanceolate-triangular, tapered to a sharply pointed tip. Receptacle flat or slightly convex at flowering, usually becoming shallowly concave at fruiting. 2n=14, 28. April–June.

Scattered, mostly south of the Missouri River (eastern U.S. west to Wisconsin, Kansas, and Texas; disjunct in Arizona; Mexico, Central America, South America, Caribbean Islands; introduced widely in the Old World). Upland prairies, sand prairies, glades, savannas, openings of mesic to dry upland forests, tops of bluffs, and banks of streams and rivers; also pastures, old fields, fallow fields, roadsides, open, disturbed areas, and rarely lawns.

The small, bulbous, basal cells of the hairs on the leaves can only be seen under a hand lens or dissecting microscope and are best observed on the upper surface. They appear similar to minute grains of sand or small glands where they persist even after the elongate portions of the hairs have been shed or abraded away. The stem leaves of G. purpurea tend to be somewhat broader and less oblong (more strongly oblanceolate to spatulate) than those of G. argyrinea.