I 



ASCLEPIADACE^. (mILKWEKD FAMILY.) 341 



of the peduncles (2-3° liigli), very leafy ; leaves oblong-lanceolate, acute or 

 pointed, obtuse or oltscurely heart-shaped at base; Howers rose-jjurple ; hoods 

 scarcely equalling tiie slender needle-pointed horn.— S\\ainj)8, common. — 

 Var. PULCHKA, Pers. ; leaves broader and shorter-petioled, nnjre or less hairy- 

 pubescent, as well as the stem. Milky juice scanty. — With the smooth form. 

 * * * Flowers greenish, i/e/lowish^ white, or mereli/ purji/ish-tiiifjed : leaves oppo- 

 site or ichorled, or the upjnr nircl ij scattered. 

 -t- Follicles echinaie with soft spinous processes, densely tomentose {smooth, and 

 onlij minutely echinate at the apex in u. S), large (3 -5' long), ovate and acu- 

 minate, erect on dejiexed pedicels; leaves large and broad, short-petioled ; 

 umbels terminal and lateral. 



6. A. speciosa, Torr. Finely cauescent-tomentose or glabrate, f Ae many- 

 Jlowercd umbel and calyx densely tomentose; leaves subcordate-oval to oblong; 

 corolla-lobes purplish, ovate-oblong, 4 - 5" long ; hoods 5 - 6" long, with a short 

 inflexed horn, the truncate summit abruptly produced into a very long lanceolate- 

 ligulate appendage. — Along streams, Minn, to Ark., and westward. 



7. A. Cornuti, Decaisne. (Common Milkwekd or Silkwekd.) Stem 

 tall and stout, finely soft-pubescent; leaves oval-oldong (4-8' long), pale, mi- 

 nutely downy beneath, as well as the peduncles, etc. ; corolla-lobes dull purple 

 to white, 3-4" long; hoods rather longer than the anthers, ovate, obtuse, ivitli 

 a tooth each side of the short stout claw-like horn. — l\ich ground, everywhere. 



8. A, Sulliv^ntii, Engelm. Very sjnooth throughout, tall ; leaves ovate- 

 oblong with a somewhat heart-shaped base, nearly sessile ; hoods obovate, en- 

 tire, obtusely 2-eared at the base outside ; flowers larger (9" long) and more 

 purple than in the last ; anther-wings 2-toothed at base ; pod nearly glabrous, 

 obscurely spiny chiefly on the beak. — Low grounds, Ohio to Kan. and Minu. 



-»- -*- Follicles wholly unarmed, either glabrous or tomentulose-pubescent, 

 ++ Erect or ascending on the deflexed or decurved fruiting pedicels. 

 — Umbel solitary, on a naked terminal peduncle; leaves sessile, broad, trans- 

 versely veined, wavy ; glabrous and pale or glaucous. 



9. A. obtusifolia, Michx. Stem 2-3° high; leaves oblong with a heart- 

 shaped claspin;/ base, very obtuse or retuse (2^ - 5' long) ; peduncle 3-12' long ; 

 corolla pale greenish purple , hoods truncate, somewhat tootlied at the sum- 

 mit, shorter than the slender awl-j)ointed horn. — Sandy woods and fields, not 

 rare, especially southward. A second umbel at the base of tlie peduncle occa- 

 sionally occurs. 



10. A. Meadii, Torr. Stem sleiuler (1 -2° high) ; leaves ovate or oblong- 

 ovate, obtuse or acutish (1^-2^' long) , peduncle only twice the length of the 

 upper leaves, pedicels rather short , corolla greenish-white, hoods rounded- 

 truncate at summit, and with a sharp tooth at each margin, somewhat exceed- 

 ing the stouter horn. — Dry ground. 111. and Iowa. June. 



= = Umbels mostly more than one ; peduncle not overtopping the leaves. 

 a. Leaves large, orbicular to oblong-lanceolate : hoods broad, little if at all exceed- 

 ing the anthers ; glabrous or some minute pubescence on young parts. 



11. A. Jam^Sii, Torr. Stem stout (1° high or more); leaves about 5 

 pairs, approximate, remarkably thick, rounded or bioadly oval, rften emarginafe, 



