11. Physalis pubescens L. (downy ground cherry, annual ground cherry)

P. pubescens var. glabra (Michx.) Waterf.

P. pubescens var. integrifolia (Dunal) Waterf.

P. barbadensis Jacq.

P. barbadensis var. glabra (Michx.) Fernald

Pl. 565 j–n; Map 2633

Plants annual, more or less taprooted. Stems (5–)10–80 cm long, erect or ascending, unbranched or with relatively few, loosely ascending to spreading branches, glabrous or sparsely to moderately pubescent (at least toward the tip) with short, spreading, multicellular, mostly gland-tipped hairs 0.1–0.5 mm long, often also with moderate to dense, longer (1–3 mm), spreading, nonglandular hairs. Leaves short- to long-petiolate. Leaf blades 2–8 cm long, ovate to broadly ovate or nearly circular, angled or short-tapered to a sharply pointed tip, broadly rounded to more or less truncate at the base, the margins entire or relatively sparsely toothed (with 1–3[–7] main teeth along each side), minutely hairy, the teeth bluntly or sharply pointed, shallow and broad, the surfaces green when fresh, drying uniformly green (lacking orangish tinging or patches), sparsely to moderately pubescent (more densely on the undersurface) with short, mostly gland-tipped, multicellular hairs. Flower stalks 3.5–9.0 mm long, becoming elongated to 6–15 mm at fruiting. Calyces 3–6 mm long at flowering, the lobes 1.0–3.5 mm long, the outer surface with sparse to dense, short, multicellular, nonglandular hairs at flowering, persistently hairy at fruiting, at fruiting becoming elongated to 20–30 mm long, sharply 5-angled, concave at the base, green or pale brown to tan. Corollas 6–11 mm long, pale yellow to lemon yellow, the inner surface with 5 large, prominent dark purplish brown to dark reddish brown spots toward the base (these sometimes merged into a ring or appearing smudged). Stamens with broad filaments about as wide as the anthers, the anthers 1–2 mm long, blue or bluish-tinged, arched but not coiled after dehiscence. Fruits 1.0–1.2 cm long, green or yellow, occasionally purplish-tinged. 2n=24. May–November.

Scattered nearly throughout the state, but uncommon in or absent from many counties in the northwestern quarter (nearly throughout the U.S. [except for some of the northern Plains and Rocky Mountains states]; Canada, Mexico, Central America, South America, Caribbean Islands, Pacific Islands).

Steyermark (1963) followed Waterfall (1958) in dividing this species into a number of varieties. Subsequent taxonomic studies have resulted in the segregation of P. cordata and P. grisea as distinct species, and the recognition of the remaining plants as a morphologically variable P. pubescens without the separation of further infraspecific taxa (Martínez, 1998; J. R. Sullivan, 1984, 2004).