2. Mandevilla hypoleuca (Bentham) Pichon, Bull. Mus. Natl. Hist. Nat., sér. 2. 20: 106. 1948.
Bottomwhite rocktrumpet
Echites hypoleucus Bentham, Pl. Hartw., 23. 1839 (as hypoleuca); Macrosiphonia hypoleuca (Bentham) Müller Arg.; Telosiphonia hypoleuca (Bentham) Henrickson
Suffrutescent perennials, 1.7–7.5 dm; rhizomes present. Stems densely eglandular-pubescent, especially on younger growth. Leaves opposite, subopposite, or subverticillate; petiole 1–4 mm, pubescent; blade linear to oblong-elliptic or oblong-ovate, 25–50(–70) × (4–)8–17(–21) mm, subcoriaceous, base subcordate or rounded, margins revolute or not, apex acute or rounded, apiculate, surfaces densely white eglandular-pubescent abaxially, eglandular-pubescent adaxially. Cymes 1 or 2(or 3)-flowered. Peduncles (5–)10–22(–36) mm, pubescent. Pedicels 7–15 mm, pubescent. Flowers: sepals reddish, oblong-linear, 7–10(–12) × 1.2–2 mm, pubescent; corolla white, often tinged with pink or red, eglandular-pubescent abaxially and adaxially, tube (8–)15–35 × 2.5–3 mm, throat (13–)17–25(–30) × 7–9 mm, lobes spreading, obliquely ovate, 15–30 × 14–28 mm. Follicles (80–)100–150 × 3–5 mm, pubescent. Seeds 6–8 × 1.5–2 mm.
Flowering summer–fall; fruiting summer–fall. Pine-oak woodlands, desert grassland ecotones, mostly on soils derived from igneous rock; 1000–1800 m; Tex.; Mexico.
Mandevilla hypoleuca has been reported from the Chinati, Chisos, and Davis mountains of western Texas but has not been well collected; most specimens date from the 1940s or earlier. The current status of the species in the flora area is uncertain, although it is widespread in northern and central Mexico.
