96 ASCLEPIADACE^E. Ascleplas. 



petiole : lobes of the greenish corolla oblong (half inch long) : column hardly any below 

 the greenish white hoods, which are little shorter than the petals, almost thrice the length 

 of the anthers, barely retuse at apex ; tlie truncate upjier edge of the crest erose ; the 

 exserted horn fi'om its inner angle thin-subulate, a line long : auricles at base of the hood 

 very small, roundish : anther-wings broadly rounded at base : follicles not seen. — Proc. 

 Am. Acad. xii. 70. — Rock Spring, Providence Mountains, S. E. California, Palmer. 



++ -H- Follicles pendulous on recurving pedicels, at least not erect : leaves subulate-filiform or 

 wanting ou the junciform naked stems: hoods elongated, broader upward. 



A. SUbulata, Decaisne. Cinereous-puberulent or soon glabrous and glaucous : stem 

 3 or 4 feet high, naked and rush-like or bearing a few nearly filiform leaves, usually few- 

 branched above : umbels terminal and lateral, 5-20-flowcred, on peduncles mostly shorter 

 than the x^edicels : flowers yellowish-white : lobes of the corolla oblong, 4 or 5 lines long : 

 column distinct : hoods purplish, narrowly oblong-panduriform, erect, twice the length 

 of the column, entire, a narrow crest adnate up to the apex, above dilated and inwardly 

 pointed by a very short and blunt subulate horn ; 10 short internal appendages forming 

 a pair of fleshy auricles within the base of each hood : follicles fusiform and long-acu- 

 minate, 4 inches long, smooth. — DC. Prodr. viii. 571 ; Torr. in Pacif. R. Rep. v. 3(32, t. 7. 

 — Desert region of S. E. California and W. Arizona. (Lower Calif., W. Mex.?) 



++ -H- ++ Follicles erect on erect fruiting pedicels, fusiform: leaves not rarely verticillate, in one 

 species con)uionly aheniate: hoods moderately if at all exceeding the anthers. 



= Leaves from ovate to broadly lanceolate, glabrous or nearly so, thin, rather slender-petioled : 

 corolla white or pinkish. 



A. quadrif olia, L. A foot or two high, simple, usually leafless below : leaves 3 or 4 

 pairs, or commonly a whorl of four in place of each middle pair, ovate to ovate-lanceolate, 

 acuminate, 2 to 4 inches long : umbels 2 to 4, loosely many-flowered : pcduTicle seldom 

 longer than the slender pedicels : corolla from light pink to almost white ; the lobes 2^ 

 lines long, oblong : column short : hoods white, twice the length of the anthers, ovate- 

 oblong, a salient tooth or lobe on each margin toward the base ; horn short, very broadly 

 falcate-subulate, incurved over the anther-tips. — Jacq. Obs. t. 33; Barton, Fl. Am. Sept. 

 ii. t. 43; Lodd. Bot. Cab. t. 1258. A. vanilla, Raf. in Am. Month. Ma:g. iv. 30 (1818), ex 

 Neob. G2. — Dry soil, Canada and Wisconsin to N. Carolina and Arkansas. 

 A. perennis, W^alt. Stem a foot or two high, commonly branching, leafy throughout, 

 sometimes rather woody at base : leaves all opposite, from ovate to oblong-lanceolate, 

 mostly acuminate at both ends, 2 to 4 inches long : umbels several and rather small, on 

 peduncles of about twice the length of the pedicels : flowers white throughout : lobes of 

 the corolla 1 or 2 lines long, oblong : column narrow, half to three fourths of a line long : 

 hoods oval, entire, erect, not twice tlie length of the column, hardly surpassing the an- 

 thers, one third shorter than ilieir straightish or falcate almost filiform horn : seeds not 

 rarely destitute of coma. — Car. 107 ; Gray, Man. ed. 5, 396; Chapm. Fl. 365. A. dehilis, 

 Michx. Fl. i. 116, in part ; the Obs. relates to A. quadrifolia. A. parviflora, Ait. Kew. i. 307 ; 

 Pursh, Fl. i. 180 ; Decaisne, 1. c. Matalea ? hvvis, Nutt. in Am. Jour. Sci. v. 2!)1. — Muddy 

 shores, &c., from S. Indiana and Illinois, and from Carolina to Florida and Texas. 



Var. parvula, barely a foot high, and leaves an inch or two long. — Torr. Bot. Mex. 

 Bound. 164. — Head of Rock Creek, W. Texas, Bigelow, Wrirjlii. 



A. NivEA, L. (Dill. Elth. t. 29, & Plum. Ic. t. 30), is a W. Indian species (Griseb. Fl. W. 

 Ind., excl. syn. Bot. Mag.), very near A. percvnis, but corolla greenish-white, hoods longer 

 than the anthers, the wings of which become auriculate-undulate next the base, and are 

 not overtopped by the horn. " Louisiana," Grisebach, 1. c. ; but this is probably a mistake. 



A. vikgAta. Lag. Gen. & Spec. 14, Sweet Brit. Fl. Gard. sor. 2, t. 85 {A.niifjnsflfolia, Hort. 

 Bcrol.,-Roem. & Sc^i., & .4. linearis of gardens, A. linifolla, HBK. 1) is a nearly related species, 

 with white or rose-tinged corolla, anther-wings plane, and narrow leaves as of the succeeding 

 section, probably only Mexican. See Proc. Am. Acad. xii. 70. 



= = Leaves from elongated-lanceolate to liliform, sessile or nearly so, glabrous. 



a. Corolla retlexed (as in the genus generally): horn of the hoods subulate and exserted. 



1. Column cons])icuous, at length about half as long as the anthers. 



A, Mexicana, CeJV. Stem 3 to 5 feet high : leaves in whorls of 3 to 6, or uppermost and 



lower opposite, sometimes also in axillary fascicles, linear or narrowly lanceolate (3 to 6 



