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 

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

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

 short-pedunclcd or sessile : pedicels little longer than the purplisli or greenish flowers : 

 corolla-lobcs ovate, 2 lines long : column liardlj' 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. 16J:, t. 45. — Rockj^ hills along 

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

 Bigelow, Parry, Wriijlit. 



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

 hoods obtuse, twice or thrice tlie longtli of tlie antliers, not tapering to base, entire at summit, 



1. Involute-concave or more open; the falcate or subulate liorn free at or b -low the middle of the 

 hood, and incurved or inflexed over tlie 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 

 potioled (1-J- to 3 Inches long), glabratc 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 auriculatc 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- 

 ialliana, 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 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. ovalifolia, Gray in Proc. Acad. Philad. March, 1803, 75, 

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

 Brandegee, &c. Follicles tomentulose, glabrate. In aspect resembles A. Su/livantii, 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-petiolcd (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 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- 

 appendagcd 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 bicorniculate at the basal angle (in tlie manner of A. ohtusifnh'a and-^4. Siil- 

 livnntii). — Sk. i. 321 ; Decaisne, 1. c. 570 (excl. syn. Torr.) ; Chapm. Fl. 303. — Dry groimd, 

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



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

 wing ; tlic latter Ijcarinjj: two semi-ohovate lamelhv, its broad upper part enclosing a lamelliform 

 crest of equal widtli, wliich bears a short subulate exserted horn at the inner angle. 



A. nyctaginifolia, 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 



