204 BOTANY. 



Onosmodium Thubbeei, Gray, Syn. Fl. p. 205. (Macromeria viridiflora, 

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

 high hispid with spreading hairs; leaves ovate-lanceolate, 2 to 3 J inches 

 long, 6 to 12 lines wide, covered on both sides with a close appressed pubes- 

 cence, hispid also on the upper side with stiffish, 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 very 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^. 



Ipomoea hedeeacea, Jacq. Cray, Syn. Fl. part 1, p. 210. (Ipomoea Nil, 

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

 an acre in area. 



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

 diversifolia, Ohoisy in DC. Prod, ix, p. 343. Pharbitis 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). 



Ipomgsa mueicata, Cav. — Nearly smooth, with a tuberose root ; stem 

 prostrate ; leaves deeply palniately-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 slender 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- 



