Asclepias. ASCLEPIADACE^. 95 



c. Leaves extremely narrow, sessile : hoods thrice the length of the anthers, slender, acute, open. 



A. macrotis, Torr. Glabi-ous or nearly so : stems barely a span high, numerous and 

 much branched from a suffrutescent thickened base : leaves narrowly linear with revolute 

 margins, almost filiform, an inch or more long : umbels 3-5-flowered, terminal and lateral, 

 ahort-peduncled or sessile : pedicels little longer than the purplish or greenish flowers : 

 corolla-lobes ovate, 2 lines long : column hardly any : hoods with ovate erect base as long 

 as the anthers, above contracted into a gradually attenuate twice longer subulate spreading 

 portion, the apex incurving; the broad horn short and blunt, with barely exscrted apex: 

 follicles ovate-lanceolate, an inch long. Bot. Mcx. Bound. 164, t. 45. Rocky hills along 

 the Bio Grande, borders of Texas, New Mexico, and Chihuahua, especially near El Paso, 

 Bigelow, Parry, Wrifjht. 



d. Leaves from ovate to oblong, mostly pubescent or puberulent : stems erect, a foot or more high : 

 hoods obtuse, twice or thrice the length of the anthers, not tapering to base, entire at summit, 



1. Involute-concave or more open; the falcate or subulate horn free at or below the middle of the 

 hood, and incurved or inflexed over the stigmatic disk : follicles tomcntose or soft-pubescent. 



A. OValif 61ia, Decaisne. Tomentulose-pubescent : stem rather slender : leaves thin- 

 nish, from ovate or oval to ovate-lanceolate, mostly acute, rounded at base, distinctly 

 petioled (H to 3 inches long), glabrate with age, at least the upper face, the midrib as 

 well as primary veins slender, and veinlets reticulated : umbels few, loosely 10-18-flowered, 

 on peduncles which seldom equal the pedicels, or sometimes sessile : corolla greenish-white 

 with purplish outside ; the lobes oblong-ovate, 2 or 3 lines long : hoods oval or broadly 

 oblong in outline, not auriculate at base, the inner margins below the middle extended into 

 a large acute tooth or lobe ; the horn broad and rather short : anther-wings rounded and 

 entire or minutely and obscurely notched at the prominent base. DC. Prodr. viii. 567 

 (excl. habitat) ; Gray, Man. cd. 5, 396. A. variegatu, var., Hook. Fl. ii. 252, t. 141. .4. Nut- 

 talliuna, Gray, Man. ed. 2, 352, 704. Saskatchewan, Lake Winnipeg, and Dakotah to K 

 Illinois and Wisconsin, in oak-openings and prairies. 



A. Hallii, Gray. Puberulcnt, glabrate : stem stout : leaves thickish, ovate-lanceolate or 

 oblong-lanceolate with rounded base and rather acute apex (3 to 5 inches long), short- 

 petioled, the stout midrib and the slightly ascending straight veins prominent underneath : 

 umbels few and corymbose, many-flowered, on peduncles somewhat longer than the 

 pedicels : corolla greenish-white and purplish ; the lobes oblong, 3 lines long : hoods elon- 

 gated-oblong in outline (3 lines long), entire, hastately 2-gibbous above the narrower base, 

 a little surpassing the sickle-shaped horn : anther-wings even and unappendaged at base. 

 Proc. Am. Acad. viii. 09. A. ovu/ifolia, Gray in Proc. Acad. Philad. March, 1863, 75, 

 coll. E. Hall, n.480. Colorado, near Denver? E. Hall. Head-waters of the Arkansas 

 Brandcfjee, &c. Follicles tomentulose, glabrate. In aspect resembles A. Sullivantii, but with 

 some pubescence, and base of the anther-wings destitute of the corniculation. 



A. obovata, Ell. Cinereous with soft pubescence or tomentum on the lower face of the 

 leaves : stem a foot or two high : leaves oval or oblong, only the lower obovate, somewhat 

 undulate, mucronate-apiculate, rounded or subcordate at base, very short-petioled (li to 3 

 inches long), the midrib stout, the veins transverse and slender : umbels (3 or 4 at the 

 upper axils) almost sessile, densely 10-14-flowered : lobes of the yellowish-green corolla 

 oblong, 3 or 4 lines long, half the length of the pedicels : hoods purplish, oblong, strictly 

 erect (3 or 4 lines long), involute so that the thin inner edges meet for almost their whole 

 length, dorsally hastately bigibbous above a short contracted base, thence narrowly wing- 

 appendaged upward and inward for some length, a pair of broad and short fleshy internal 

 auricles at very base within ; horn narrowly falcate, fleshy ; the exserted upper part of 

 the free portion strongly inflexed, subulate ; upper or dorsal face canaliculate-concave : 

 anther-wings bicorniculate at the basal angle (in the manner of A. obtnsi folia and A. Snf- 

 livantii). Sk i. 321 ; Decaisne, 1. c. 570 (excl. syn. Torr.) ; Chapm. Fl. 363. Dry ground, 

 S. Carolina, near the coast, to Florida and Louisiana. 



2. Hoods laterally much compressed, mainly solid, with a narrow dorsal keel and a broader ventral 

 wine;; the latter bearing two semi-obovate lamelke, its broad upper part enclosing a lamelliform 

 crest of equal width, which bears a short subulate exserted horn at the inner angle. 



A. nyctaginifolia, Gray. Ronghish-puberulent, apparently a foot high and ascending: 

 leaves rhombic-ovate, with ascending and branching veins, 2 or 3 inches long, rather long- 

 petioled : umbels all lateral, very short-peduncled, 4-20-flowered : pedicels equalling the 



