ASCLEPIADACEJE. (MILKWEED FAMILY.) 341 



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

 pointed, obtuse or obscurely heart-shaped at base ; flowers rose-purple ; hoods 

 scarcely equalling the slender needle-pointed horn. Swamps, common. 

 Var. PULCHRA, Pers. ; leaves broader and shorter-petioled, more or less hairy- 

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

 * * * Flowers greenish, yellowish, white, or merely purplish-tinged ; leaves oppo- 

 site or whorled, or the upper rarely scattered. 



- Follicles echinate with soft spinous processes, densely tomentose (smooth, and 

 only minutely echinate at the apex in n. 8), large (3 - 5' long), ovate and acu- 

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

 umbels terminal and lateral. 



6. A. speciosa, Torr. Finely canescent-tomentose or glabrate, the many- 

 flowered umbel and calyx densely tomentose ; leaves subcor -date-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. Corntlti, Decaisne. (COMMON MILKWEED or SILKWEED.) Stem 

 tall and stout, finely soft-pubescent; leaves oval-oblong (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, with 

 a tooth each side of the short stout claw-like horn. Rich ground, everywhere. 



8. A. Sullivantii, Engelm. Very smooth 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 chiejly on the beak. Low grounds, Ohio to Kan. and Minn. 



- H- Follicles wholly unarmed, either glabrous or tomentulose-pubescent, 



w. 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. obtusifblia, Michx. Stem 2-3 high; leaves oblong with a heart- 

 shaped clasping base, very obtuse or retuse (2j - 5' long) ; peduncle 3 - 12' long ; 

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

 mit, shorter than the slender awl-pointed horn. Sandy woods and fields, not 

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

 sionally occurs. 



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

 ovate, obtuse or acutish (l--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. Jamesii, Torr. Stem stout (1 high or more); leaves about 5 

 pairs, approximate, remarkably thick, rounded or broad!// oval, often emarginate. 



