2. Gamochaeta pensylvanica (Willd.) Cabrera

Gnaphalium pensylvanicum Willd.

Gnaphalium purpureum L. var. spathulatum (Lam.) Ahles

Pl. 295 e; Map 1136

Plants usually with slender taproots, less commonly fibrous-rooted. Stems 10–45 cm long. Basal leaves usually present at flowering. Leaves 1–7 cm long, narrowly obovate to oblanceolate or spatulate, the upper ones sometimes linear, slightly to moderately bicolorous, the upper surface moderately to densely woolly but still appearing somewhat darker or greener than the undersurface, the undersurface densely woolly, the hairs with a slender, unexpanded basal cell (even with magnification). Involucre 3.0–3.5 mm long, the outermost bracts ovate-triangular with sharply pointed tips, the innermost lanceolate-triangular, tapered to a sharply pointed or less commonly bluntly pointed tip. Receptacle flat or slightly concave at flowering, becoming deeply concave (cuplike) at fruiting. 2n=28. April–June.

Possibly introduced, uncommon, widely scattered, mostly south of the Missouri River (southeastern U.S. north to Pennsylvania and west to Oklahoma and Texas, disjunct in California; Mexico, Central America, South America; introduced widely in the Old World). Upland prairies and glades; also pastures, old fields, roadsides, and open, disturbed areas.

This species can be difficult to distinguish from the more widely distributed G. purpurea based on foliage characters. The strongly concave (craterlike), mature receptacles are most easily observed after the fruits have dispersed. Nesom (2004b) has discussed the possibility that this taxon represents an early introduction into North America, possible from tropical America, but the evidence is far from conclusive, and the native range of this widespread, weedy species may never be known with certainty.