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.