Soft twinevine

Philibertia torreyi A. Gray, Proc. Amer. Acad. Arts 12: 64. 1876; Sarcostemma torreyi (A. Gray) Woodson

Stems hirsute (pilose). Leaves persistent, stipular colleter 1 on each side of petiole; petiole 1–2.5 cm, hirsute throughout; blade deltate, lanceolate, or ovate, 2–5.5 × 1.5–2.5 cm, chartaceous, base sagittate or cordate, margins plane, apex acute or attenuate, mucronate, venation pinnipalmate, main veins often conspicuously pale, surfaces hirsute, margins ciliate, laminar colleters 4–10. Inflorescences solitary at nodes, 8–15-flowered; peduncle 2–7 cm, hirsute; bracts cadu­cous, 1, at base of each pedicel. Pedicels 10–17 mm, hirsute. Flowers: calyx lobes narrowly lanceolate to narrowly elliptic, 4–6 mm, apex acute to acuminate, erect, hirsute, ciliate, colleter 1, in sinuses; corolla cream to pink or purplish with red or purplish blotches or stripes at bases and near tips of lobes, rotate-campanulate, tube 2–2.5 mm, lobes ascending, lanceolate to ovate, 6–9 mm, apex acute to obtuse, apiculate, hirsutulous abaxially, minutely hirtellous adaxially, margins conspicuously ciliate with flattened trichomes; corona ring cream, inflated corona segments proximally green, distally glossy white, ovoid, 2–3 mm; style apex shallowly con­vex. Follicles usually solitary, lance-ovoid, 8–9 × 1–1.5 cm, apex long-attenuate, puberulent. Seeds 20–50, light brown, thickly winged, biconvex, lanceolate, 6–7 × 3–4 mm, both faces papillate; coma white, 3 cm.

Flowering May–Oct; fruiting Sep–Oct. Canyons, arroyos, dry slopes, ridges, plains, igneous substrates, juniper and oak woods, thorn scrub, desert scrub; 1200–2100 m; Tex.; Mexico (Coahuila, Nuevo León, Tamaulipas).

Funastrum torreyi barely enters the flora area in the Big Bend region of Texas. It is apparently not common and re-evaluation of its conservation status is warranted. It has the largest and showiest flowers of the Funastrum species in the flora region.