Asclepias. ASCLEPIADACE^. 95 



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



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

 nmch branched I'roui a suftVutescent thickened base : leaves narrowly linear with revolute 

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

 short-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 cxserted apex : 

 follicles ovate-lanceolate, an inch long. — Bot. Mex. Bound. IG^ t. 45. — Rocky hills along 

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

 Bigelow, Parrij, Wrir/ht. 



d. Leaves from ovate to oblong, mostly jjiibesceiit or pub -rulent : stems erect, a foot or more high : 

 hoods obtuse, twice cr 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 indexed over the stigmatic disk : follicles tomcutose or soft-pubescent. 



A - OValif olia, Decaisne. Tomentulose-iiubescent : stem rather slender : leaves thin- 

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

 petioled (li 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-lS-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. 507 

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

 talUana, Gray, Man. ed. 2, 352, 704. — Saskatchewan, Lake Winnipeg, and Dakotah to X. 

 Illinois and Wisconsin, in oak-openings and prairies. 



A . Hallii, Gray. Pubemlent, 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 inirplish ; 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. ovalifoUa, Gray in Proc. Acad. Philad. March, 1803, 75, 

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

 Branclegee, &c. Follicles tomentulose, glabrate. In aspect resembles A. Sulltvaidii, 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 (1^ 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 tlie 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 exserte<l upper part of 

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

 anther-wings bicorniculate at the basal angle (in tlie maimer of A. obtnsifolia and A. Siil- 

 livantii). — Sk i. 321 ; Decaisne, 1. c. .')70 (excl. syn. Torr.) ; Cliapm. Fl. 363. — Dry ground, 

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



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

 wing; the latter bearing two semi-obovate laniellic, its broad ujiper part enclosing a lamelliforui 

 crest of equal width, wiiich i)ears a short subulate e.xserted horn at tiie inner angle. 



A. nyctaginif61ia, Gray. Roughish-pulierulent, apparently afoot high and ascending.* 

 leaves rhond)ic-ovate, with ascending and branching vein,?, 2 or 3 inches long, rather long- 

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



