Novon 12: 328. 2002.
Perennials; caudex simple or branched, (woody); densely (silvery) pubescent, trichomes (short-stalked), 4–8-rayed, rays furcate or bifurcate, (finely tuberculate throughout). Stems simple or few from base, decumbent, (straggling and flexuous, usually branched distally), 4–8 dm. Basal leaves: blade narrowly elliptic to oblanceolate, 4–12 cm, margins entire, sinuate, or shallowly dentate, (apex acute). Cauline leaves (sessile or proximal shortly petiolate); blade linear to narrowly elliptic, 3–4 cm, margins entire, sinuate, or remotely dentate, (apex acute). Racemes loose, (sometimes greatly elongated). Fruiting pedicels (recurved), 15–20(–25) mm. Flowers: sepals elliptic, 3.5–4 mm, (lateral pair subsaccate, median pair thickened apically, cucullate); petals broadly obovate, 4–5 mm, (sometimes with short, broad claw). Fruits (pendent), subglobose or broadly ovoid, slightly compressed, 5–7 mm; valves (not retaining seeds after dehiscence), glabrous throughout; ovules per ovary unknown; style 1.5–2 mm. Seeds flattened. 2n = 16.
Phenology: Flowering Apr.
Habitat: Sandy soils, entangled in shrubs, cactus clumps
Elevation: 1700-1800 m
Of conservation concern.
Physaria thamnophila is found in sandy areas with shrubs and cactus in sparse shrubland communities of Starr and Zapata counties. It sometimes flowers through September with sufficient moisture.