Asclepias. ASCLEPIADACE^. 95 



c. Leaves extremely nan-ow, 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 



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

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

 short-peduncled or sessile: pedicels little longer than the pui-plish 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 exserted apex • 

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

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

 Bigelow, Parry, Wright. ' 



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 b.^low the middle of 'the 

 hood, and incurved or mflexed over the stigmatic disk : follicles tomentose or soft-pubescent. 



A. OValif olia, Decaisne. Tomentulose-pubescent : 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 10-18-flowered, 

 on peduncles wliicli 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. ed. 5, 396. A. variegata, var.. Hook. Fl. ii. 252 t. 14L A Nut- 

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

 Illinois and Wisconsin, in oak-openings and prairies. 



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

 oblong-lanceolate with rounded base and rather acute apex (3 to 6 inches long), short- 

 petioled, the stout midrib and the slightly ascending straight veins promment 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 outHne (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. G9. A. ovalifoUa, Gray in Proc. Acad. Philad. March, 1863 75 

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

 Brandegee, &c. PoUicles 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 (U to 3 

 inches long), the midrib stout, the veins transverse and slender : umbels (3 or 4 a't 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 Aving- 

 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, its upper or dorsal face caniculate-concave : 

 anther-wings bicomiculate at the basal angle (in the manner of A. obtnsifoUa and A. Svl- 

 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 



wing ; the latter bearing two semi-obovate lamella», its broad upper part enclosing a lamelliform 



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



A. nyctaginif olia, Gray. Roughish-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-petioled, 4-8-flowered : pedicels equalling the 



