ASCLEPIADACEiE. 403 



7. ACERATES, Ell. An extension of the generic character, as to the 

 hoods, is needed to include the following, which in other respects falls under the 

 second division, p. 99. 



A. bifida, Rusby. Generally resemV)ling A. virkhjlora, a foot or two high, tomentose- 

 pubcrulent: leaves obloiig-laiiccolate, taperiug iuto short petioles : pedicels rather slender: 

 hoods of the crown paler, rather shorter than the authei's, /M-o-pa?-^ef/, the divisions lanceolate. 

 ■ — Gray, Proc. Am. Acad. xx. 29G. — Arizona, probably in Yavapai Co., Rusbij, 1883. 



9. GOMPHOCARPUS, R. Br. 



G. tomentosus, Gray, p. 100. Hoods dark brown-purple, the solid part not much smaller 

 tliau the valves: the structure not to be confounded with that of Scluzonotus,ioT the 2-valved 

 portion is only apparently dorsal, the whole organ being pendulous or rcsupinate. It ia 

 similar in G. lanatus of S. Africa, except that the hood is ascending. 



G. hypoleucus. Gray. Tomentulose : stem robust, 2 feet high, leafy: leaves all opposite, 

 oval or oblong, short-petioled, green and glabrate above, canescently tonientose beneath : 

 umbels long-petioled, many-flowered: corolla greenish with the upper face dull ])urple : 

 hoods brown-purple, erect, much surpassing the anthers, liugulate, Heshy, nearly solid and 

 entire, except a pair of triangular and acute strictly iuflexed lobes at base. — Proc. Am. 

 Acad. xvii. 222. — Mountains of S. Arizona, Pniujle, Lemmon. 



12. METAST:ELMA, R. Br., § Eumetastelma. P. 101, add: — 



M. Palmeri, Watson. Glabrous : leaves lanceolate, acutish or obtuse at base, about an 

 inch long : cymes loosely 2-6-flowered, subsessile or short-peduncled : calyx-lobes ovate, ob- 

 tuse : corolla not over a line and a half long, 5-pai"ted ; its lobes oMong or narrower, merely 

 puberulcnt within: scales of the crown lanceolate and ;icuminate or o\'ate-.'*ubulate, inserted 

 at base of extremely short column, a little surpassing the stigma. — Proc. Am. Acad, xviii. 

 115, as to pi. Palmer only; Gray, Rev. Metastelma in Proc. Am. Acad. xxi. — W. and S. 

 borders of Texas, Palmer, Reverchon. (Adj. Mex.) 



M. Arizonicum, Gray. Puberulcnt, lignescent at base: leaves thicki.sh, narrowly linear 

 or some linear-oblong, veinless : flowers fascicled and short-pedicelled : calyx-lobes subulate : 

 corolla 2 lines long, thickish, deeply S-parted ; loi)es linear-lanceolate, densely villous- 

 pubescent inside ; scales of the crown linear-subulate, inserted at base of very shoi't col- 

 umn, surpassing the stigma. — Proc. Am. Acad. xix. 85. — Hills near Tucson, Arizona, 

 Pringle. 



14. VINCETOXICUM, Moench. (Derivation doubtless from vincere, to 

 overcome, toxicum, poison, as has been well shown.) 



V. palustre, p. 102. Add. syu.: Ci/nanchinn maritimiim, Maxim, in Bull. Acad. Petrop. 



ix. 800. 

 V. SCOparium, p. 102. Leafy plants not rarely bear leaves an inch or two long, a line or 



two wide. 



14^ R0TI-IR6CKIA, Gray. (Professor Joseph Trimble liofhrock, author 

 of the Botanical Part (vol. vi.) of Wheeler's U. S. Geographical Surveys of the 

 region in which the plant was discovered.) — Proc. Am. Acad. xx. 295. — Single 

 species. 



R. COrdifolia, Gray, 1. c. Perennial herb, lignescent at base, spreading and twining, pu- 

 bescent and more or less hirsute : leaves opposite, slender-])ctioled, cordate, acutely acumi- 

 nate : flowers in simple or compound raccmiform loose racemes in tlie axils of the leaves: 



