1. Rhynchosida physocalyx (A. Gray) Fryxell, Brittonia. 30: 458. 1978.
Beaked sida, buffpetal Beaked sida, buffpetal
Sida physocalyx A. Gray, Boston J. Nat. Hist. 6: 163. 1850
Plants with large taproot. Stems with hairs scattered. Leaves: stipules 3–4 mm; petiole 1/2–3/4 as long as blade; blade 2–5 cm, apex obtuse to acute, surfaces coarsely hairy, hairs stellate abaxially, simple adaxially. Pedicels slender, 1–2 cm. Flowers: calyx green-membranous, lobes apiculate; petals yellow [red basally], 5–8 mm, subequal to calyx; staminal column 3–4 mm, glabrous. Schizocarps 8–9 mm diam.; mericarp blackish. Seeds 2 mm. 2n = 16.
Flowering spring–late fall. Deciduous forests, shrublands, roadsides, fencerows, disturbed habitats, sometimes in pastures and lawns; 0–1500 m; Ariz., N.Mex., Okla., Tex.; Mexico; South America (Argentina, Bolivia, Brazil, Uruguay).
While this distinctive species, with its Physalis-like inflated fruits, is thought to be native over a wide area and disjunct between southern South America and Mexico and the United States, it is most commonly found in disturbed habitats as are so many other herbaceous mallows.