204 BOTANY. 



Onosmodium Thurberi, 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^ 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). 



CONVOLVULACEtE. 



Ipomcea hederacea, Jacq. Gray, Syn. Fl. part 1, p. 210. (Ipomcea 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. {Ipomcea Nil, var. 

 diversifolia, Choisy 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). 



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 slender stems 

 hardly a foot long ; flowers infundibuliform and somewhat disproportion- 

 ately large. — Sanoita Valley, Arizona (G23). 



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- 



