204 BOTANY. 



Onosmodium Thubbbbi, Gray, Syn. FL p. 205. (Macromcria viridi/bra, 

 Torr. in Mex. Bound. Surv. p. 139, not of A. DC.) — Stem erect,2 to 3 feet 

 high hisjtid with Bpreading hairs: leaves ovate-lanceolate, 2 to 3i inches 



long-, G to 12 lines wide, covered on botli sides with a close appressed pubes- 

 cence, hispid also on the upper side with stiflish, erect hairs arising from a 

 callous base, and on the under side with softer, somewhat villous hairs, 

 especially on the rib-like nerves, sessile and partly clasping; flowers one 

 inch and a half Long, tubular-funnelform, greenish and Aery hairy on the 

 outside, yellow within ; calyx about one-fourth the length of the corolla, 

 the divisions much elongated in fruit; stamens at first included, but at 

 length exserted; nutlets ovate, more than a line long, smooth and shining. 

 Willow Spring, Arizona, 1874, Rothrock (227). 



CONVOLVULACE.E. 



Ipomcea iiedeeacea, Jacq. Gray, Syn. Fl. part 1, p. 210. {Ipomoea Nil, 

 Roth.) — Southern Arizona (505, 524), where it forms dense masses, often 

 an acre in area. 



Ipomcea Mexicana, Gray, Syn. Fl. part 1, p. 210. {Ipomoea Nil, var. 

 diversifolia, Choisy in DC. Prod, ix, p. 343. Pliarbitis diversifolia, Lindl. 

 Bot. Reg. t. 1988 ) — Probably only a form, distinguished (so far as my 

 specimen shows) by its shorter, broader calyx-lobes, and also, on authority 

 of Choisy, by the lower leaves being cordate-acuminate, and the others 

 3-lobed. — Arizona (150 a, Loew). 



Ipomcea muricata, Cav. — Nearly smooth, with a tuberose root ; stem 

 prostrate; leaves deeply palmately-parted, the 6-8 divisions narrowly 

 linear, but slightly dilated upward, 4-9" long, petiole 1" long; corolla 

 12-14" long, purple, tube slender; sepals ovate or lance-ovate, obtuse or 

 slightly mucronate, evidently muriculate on the back. The Blender stems 

 hardly a foot long ; flowers infundibuliform and somewhat disproportion- 

 ately large. — Sanoita Valley, Arizona (623). 



Ipomcea costellata, Torr. — Herbaceous, smoothish or somewhat hairy, 

 branching, slender ; leaves palmately-parted, 5-7 divisions, which are linear 

 to lanceolate-spatulate, and sometimes sparingly ciliate, 4 7 long: petioles 

 2-5" long; pedicels slightly thickened; flowers purple or whitish, funnel- 



