Mandevilla macrosiphon (Torr.) Pichon

Macrosiphonia macrosiphon (Torr.) A. Heller,
Muhlenbergia 1:2. 1900.
Echites macrosiphon Torr. Bot. Mex. Bound. Surv. 158. 1859. Macrosiphonia Berlandieri A. Gray, Syn. Fl. N. Am. 2^: 83. 1878.
Erect or somewhat diffuse suffrutescent herb, 1.5-3 dm. tall; leaves ovate-elliptic to suborbicular, 1.5-5 cm. long, 1-4.5 cm. broad, at the apex abruptly obtuse or rounded, or infrequently acute to somewhat retuse and mucronulate, obtuse or rounded at the base, densely tomentulose on both sides, the petioles 2-10 mm, long; inflorescence bearing a solitary, showy, white, vespertine flower, the peduncle obsolete or essentially so; pedicel 2-5 mm. long; calyxlobes lanceolate to ovate, acute to acuminate, 10-20 mm. long, 2-5 mm. broad, conspicuously foliaceous, densely tomentulose; corolla infundibuliform, densely puberulent-papillate externally, the tube proper 35-90 mm. long, about 1.5 mm. in diameter at the base, the throat narrowly conic to subtubular, 10-25 mm. long, 5-7 mm. in diameter at the orifice, the lobes obliquely obovate, 15-30 mm. long, spreading; follicles relatively slender, continuous, 10-15 cm. long, puberulent-papillate to glabrate.
Type IvOCALITy: Texas.
Distribution: Texas, Chihuahua, and Durango.