ASCLEPIADACE^E. (MILKWEED FAMILY.) 397 



-- H~ Stem perfectly simple, producing only a single conspicuously -pedunded termi- 

 nal umbel of dull-colored largish (6" long) flowers : hoods and lobes of the co- 

 rolla broad : pods smooth : whole plant glabrous, or nearly so, and pale or glau- 

 cous : leaves closely sessile, transversely veiny. 



10. A. obtU.sif.61ia, Michx. Stem tall (2 -3 high) ; leaves wavy, oblong 

 with a heart-shaped clasping base, very obtuse or retuse (2^' -5' long) ; peduncle 

 3' -12' long; corolla pale greenish purple; hoods of the crown truncate and 

 somewhat toothed at the summit, shorter than the slender awl-pointed horn. 

 Sandy woods and fields : not rare, especially southward. 



11. A. Meadii, Torr. (in Ed. 2, addend.) Stem slender (l-2 high) ; 

 leaves ovate or oblong-ovate, not wavy, obtuse or acutish (l'-2^' long) ; peduncle 

 only twice the length of the upper leaves ; pedicels rather short ; corolla green- 

 ish-white ; hoods of the crown rounded-truncate at summit, and with a sharp 

 tooth at each margin, somewhat exceeding the stouter horn ; pod unknown. 

 Augusta, Illinois, Dr. S. B. Mead. Clinton, Iowa, Dr. Vasey. June. 



*----- Stem simple or mostly so (2 -4 high), bearing 2-5 panicled umbels on 

 a naked terminal peduncle, and sometimes single axillary ones : flowers pink-red, 

 rather large (over 6" long) : crown conspicuously elevated above the base of the 

 corolla : pods smooth : whole plant glabrous or nearly so. 



12. A. rtlbra, L. Leaves ovate or lanceolate and tapering from a rounded or 

 heart-shaped base to a very acute point, sessile or nearly so (2 f -6' long, ^'-2^' 

 wide), bright green ; umbels many-flowered ; divisions of the corolla and hoods 

 of the crown oblong-lanceolate, purple-red ; the horn long and slender. (A. lauri- 

 folia, Michx. A. acuminata, Pursh.) Wet pine-barrens, &c., New Jersey and 

 Penn. to Virginia and southward. 



13. A. paup6rcula, Michx. Stem slender (2 -4 high); leaves elon- 

 gated lanceolate or linear (5' -10' long), tapering to both ends, slightly petioled; 

 umbels 5 - 12-flowered ; divisions of the red corolla narrowly oblong ; the bright orange 

 hoods broadly oblong, obtuse, much exceeding the incurved horn. Wet pine-bar- 

 rens on the coast, New Jersey, Virginia, and southward. 



* * Leaves scattered, or some opposite : milky juice little or none : flowers orange-red. 



14. A. tuberdsa, L. (BUTTERFLY-WEED. PLEURISY-ROOT.) Rough- 

 ish-hairy ; stems erect or ascending, very leafy, branching at the summit, and 

 bearing the umbels in a terminal corymb ; leaves varying from linear to oblong- 

 lanceolate, sessile or slightly petioled ; divisions of the corolla oblong (greenish- 

 orange) ; hoods of the crown narrowly oblong, bright orange, scarcely longer 

 than the nearly erect and slender awl-shaped horns ; pods hoary. (A. deciim- 

 bens, L.) Dry hills and fields: common, especially southward. Plant 1- 

 2 high, leafy to the summit, usually with numerous and corymbed short- 

 peduncled umbels of showy flowers. 



* * * Leaves nearly all whorled, rarely alternate, crowded: flowers white, small. 



15. A. verticillata, L. (WHORLED M.) Smoothish; stems slender, 

 simple or sparingly branched, very leafy to the summit ; leaves very narrowly 

 linear, with re volute margins (2' -3' long, 1" wide), 3-6 in a whorl; umbels 

 small, lateral and terminal; divisions of the corolla ovate (greenish-white): 



