94 ASCLEPIADACE^. Asclepias. 



A. erosa, Torr. Canescent with fine and appressed white wool when young, or the stem 

 only puherulent : leaves glabrate and green with age, sessile, ovate to ovate-lanceolate, 

 acuminate, coriaceous, the base rounded or slightly cordate, the margin scarious-cartilagi- 

 nous and rough with minute irregular denticulation or erosion : umbels numerous, on pe- 

 duncles equalling (or the lower exceeding) the lanuginous pedicels : lobes of the greenish- 

 white corolla oval, fully 3 lines long, merely hoary and soon glabrate outside : column 

 distinct: hoods yellowish, with a duplication on each side at the edge below, erect and 

 nearly horizontally truncate, rather surpassing the anthers; the falcate or claw-shaped 

 horn attached below the middle and longer than the hood, incurving over the disk of the 

 stigma : ovaries glabrous : follicles canescent when young, often glabrate at maturity. — 

 Bot. Mex. Bound. 162, glabrate state. A. leucophylla, Engelm. in Am. Naturalist, ix. 349; 

 Gray, Bot. Calif, i. 476, in the canescent-lanuginous state. — Arizona on the Gila (Sckott, 

 Thurher) to S. Utah {Parry) and San Diego Co., California, Cooper, Palmer. 



Var. obtusa, a form with elliptical and very obtuse leaves and scanty wooUiness. — 

 A. leucophylla, var. obtusa, Gray, I.e. — Bartlett's Canon, interior of Santa Barbara Co., 

 California. 



A. eriocarpa, Benth. Densely floccose-woolly, even to the calyx, the loose wool hardly 

 deciduous except from the angled stem below : leaves not rarely ternate and the upper- 

 most alternate, elongated-oblong or the upper lanceolate, obtuse or subcordate at base, 

 short-petioled, 4 to 8 inches long : umbels few or several, all on stout peduncles mostly 

 longer than the pedicels : flowers dull white : corolla at first woolly outside ; the lobes 

 ovate, 3 lines long : column short but distinct : hoods shorter than the anthers, rather 

 spreading, ventricose, oblately semiorbicular in outline and open round to near the middle 

 of the back, the summits produced inwardly into an acute angle or tooth, barely enclosing 

 the falciform acute horn: ovaries glabrous or merely the summit or the styles villous: 

 "follicles densely woolly," according to Benth. PI. Hartw. 323. — California, in dry ground, 

 from near Monterey (Hartiveg) to San Diego Co. 



A. vestita, Hook. & Arn. Densely floccose-woolly, usually even to the, outside of 

 the corolla, the white wool deciduous in age : leaves from ovate to oblong-lanceolate, very 

 acute or acuminate, often subcordate, short-petioled or the upper sessile, 4 to 6 inches 

 long : umbels 1 to 4, the terminal usually peduncled, the lateral all sessile : corolla green- 

 ish-white or purplish ; the lobes ovate, 3 lines long : column very short : hoods nearly 

 erect, ventricose, slightly surpassing the anthers, entire at the back of the somewhat trun- 

 cate summit, auriculate-extended at the inner angle, the auricles or angles involute; the 

 vomer-shaped crest rather than horn attached up to the summit of the hood, blunt, not 

 exserted: an interior crown of 10 tooth-like processes in pairs between the hoods : ovaries 

 glabrous : follicles at first canescent. —Bot. Beech. 363 (not Bot. Mag. t. 4106) ; Gray, Bot. 

 Calif, i. 476. A. eriocarpa, Torr. in Pacif . R. Bep. iv. 128, not Benth. — Dry ground, Cali- 

 fornia, from the Sacramento to San Diego Co. and the Mohave. 



i. Leaves narrow (lanceolate or linear, 1 to 3 inches long), green and nearly glabrous ; the veins 

 oblique: stems branching, ascending, a span or two high: hoods obtuse, shorter or little longer 

 than the anthers: corolla-lobes oblong-ovate, about 2 lines long: column hardly any: follicles 

 ovate, acute or acuminate, when young tomentose-canescent. 



A. brachystephana, Engelm. Stems 6 to 10 inches high, very leafy, cinereous-puber- 

 ulent or tomentose when young, the inflorescence more floccose-tomentose : leaves from 

 lanceolate with a broader rounded base to linear, short-petioled (sometimes 3 inches long), 

 when young often cinereous-toraentulose beneath, very much surpassing the (3 to 8) few- 

 flowered umbels : peduncles as long as the pedicels or much shorter : floM'ers lurid-purplish : 

 hoods only half the length of the anthers, erect, strongly angulate-toothed at the front ; 

 the tip of the erect subulate horn exserted. — Torr. Bot. Mex. Bound. 163. — Dry sandy 

 soil, from Wyoming Terr, and Colorado to W. Texas and Arizona. (Adjacent Mex.) 



A. involucrata, Engelm. Minutely pubescent when young, glabrate, a span or less 

 in height : clustered stems spreading : leaves from lanceolate with roundish or subcordate 

 base to linear with acute base, short-petioled (occasionally alternate), tomentose on the 

 margins ; the uppermost involucrating the mostly solitary sessile or short-peduncled 10-20- 

 flowered umbel and commonly overtopping it : flowers greenish-white or purplish-tinged : 

 hoods ovate, moderate-longer than the anthers; the short incurved horn slightly exserted 

 from about their middle. — Torr. Bot. Mex. Bound. 163. — Sandy soil. New Mexico and 

 Arizona. (Adjacent Mex.) 



