Davis Mountain Rocktrumpet

Macrosiphonia hypoleuca (Benth.) Muell.-Arg
Linnaea30:452. 1860.
Echites hypoleuca Benth. PI. Hartw. 23. 1839. a t^^ -, «. .
Echites suaveolens Mart. & Gal. Bull. Acad. Brux. lli; 356. 1844. Not E. suaveolens A. DC. 1844.
Macrosiphonia Wrightii A. Gray, Syn. Fl. N. Am. 2^: 83. 1878. Rhodocalyx suaveolens Miers, Apoc. S. Am. 139. 1878. Rhodocalyx hypoleucus Miers, Apoc. S. Am. 140. 1878.
Erect or diffuse suffrutescent herb, 1-3 dm. tall; leaves narrowly oblong to linear, 20-90 mm. long, 4-22 mm. broad, acute, or rarely acuminate or narrowly obtuse, abruptly rounded, obtuse, or truncate at the base, dark-green and hirtellous to glabrate above, much paler and densely tomentulose beneath, the petioles 1-2 mm. long; inflorescence bearing 1-3 white vespertine flowers, the peduncle conspicuous, somewhat shorter than the leaves; pedicels 5-10 mm. long; calyx-lobes narrowly oblong-lanceolate, acuminate, 5-10 mm. long, somewhat petaloid, minutely puberulent-tomentulose ; corolla infundibuliform, finely floccose-tomentulose externally, the tube proper 10-25 mm, long, about 1.25 mm. in diameter at the base, the throat narrowly conic or subtubular, 15-25 mm. long, 5-7.5 mm. in diameter at the orifice, the lobes obliquely obovate, 15-25 mm. long, spreading; follicles stout, continuous or slightiy articulate, 9-13 cm. long, finely puberulent-papillate.
Type locality: Aguascalientes, Aguascalientes. Distribution: Chihuahua to Guanajuato and Michoacan.