ASCLEPIADACEJE. (MILKWEED FAMILY.) 239 



cially at the broader aud strongly aiigulatc ui.jter portion: poUinia pear- 

 shaped, short-caudicled. — Pruc. Am. Acad xii. G6. Anratea decumUns, 

 Decaisue. From Utah through S. Colorado aud Mew Mexico to Texas aud 

 Arkansas. 



2. ASCLEPIAS, L. Milkweed. Silkweed. 



Herbs, from deep and thickish j)C'rciiiiial roots: (h.wcrs nnibcllate ; the 

 peduncles terminal and lateral, usually between the petioles: follicles hoft- 

 echinate, warty or uaked. 



§ 1. Hoods sessile, not attenuate at base; the horn or crest ronspiruoits : anther- 

 wings broadest and usuaUy angulate-trunmte and salient at base. 



* Corolla and hoods orange-color: follicles naked, erect on a de flexed pedicel: 



leaves viosfl// irregularlij alternate, seldom opposite: juice of stem not milkif. 



1. A. tuberosa, L. Hirsute or roughish-pubescent, 1 or 2 feet high, 

 very leafy to the top : leaves from lanceolate-oblong to linear-lanceolate, ses- 

 sile or slightly petioled : umbels several and mostly cymose at the summit of 

 the stem : hoods narrowly oblong, erect, deep bright orange, much surpassing 

 the anthers, almost as long as the purplish- or slightly greenish-orange oblong 

 corolla lobes, nearly equalled by the filiform-subulate horn : follicles cinereous- 

 pubescent. — From S. Colorado and Arizona to Texas, thence eastward to 

 Florida aud Canada. Known commonly as "Butterfly-weed" or "Pleurisy- 

 root." 



* * Corolla and crown greenish, ijellowish, white, or merehj purplish-tinged : leaves 



opposite or sometimes whorled, or the upper rarebj alternate or scattered. 

 -»- Follicles echinate with soft spinous processes and denselij fomentose, large (3 to 

 5 inches long) and ventricose, erect on de flexed pedicels: leaves large and broad, 

 short-petioled, fransverselij veined : stems stout and simple, 2 to b feet high. 



2. A. speciosa, Torr. Finely canescent-tomento.se: leaves from sub- 

 cordate-oval to oblong, thickish: pedicels of the many-flowered dense umbel 

 and the calyx densely tomentose : flowers purplish, large : corolla-lobes 

 ovate-oblong: hoods spreading, the dilated body and its short inflexed horn 

 not surpassing the anthers, but the centre of its truncate summit abruptly 

 produced into a lanceolate-ligulate thrice longer termination : column hanlly 

 any: wings of the anthers notched and obscurely corniculate at base. — 

 Ann. Lye. N. Y. ii. 218. From Nebraska and Arkansas westward acro.ss the 

 continent. 



■«- •*- Follicles wholly unarmed and smooth throughout, either glabrous or 



tomentulose-pubescent. 



•M. Erect or ascending on defexed or decurved pedicels. 



= Umbel solitary on the perfccdg simple strict stem, elevated on a naked terminal 



peduncle : leaves all closely sessile, broad, transversely veined. 



3. A. Obtusifolia, Michx. Glabrous and pale or glauc« »us. 2 or 3 feet 

 high: leaves undulate, oblong or elliptical, 3 to 5 inches long, with rounded 

 or retuse apex and cordate-clasping base : peduncle 2 to 12 inches long; 



