3G2 asclepiadacejE. (milkweed family.) 



1. ASCLEPIAS, L. Milkweed. Silkweed. 



Calyx 5-partcd. Corolla wheel-shaped, deeply 5-parted, rcflcxcd. Crown 

 composed of 5 hooded leaves, each eontaining an incurved horn-like appendage. 

 Pollen-masses 10, by pairs, each pair occupying the contiguous cells of adjacent 

 anthers, and suspended by a slender stalk from the projecting angles of the stigma, 

 rollicle many-seeded. Seeds obovate, flat, usually eomose. — Perennial herbs, 

 with mostly simple (not twining) stems, and opposite alternate or whorled leaves. 

 Klowers in lateral (between the leaves) and terminal umbels. 



§ I . Stems lierhaceous : seeds eomose. 

 * Follicles spiny : leaver opposite. 



1. A. Cornuti, Decaisnc. Softly pubescent ; stem stout, erect, obscurely 

 4-angled; leaves oviil-oblong, short-petioled, mucronate, soon smooth above, the 

 lowest somewhat cordate ; umbels numerous, many-flowered, long-peduncled ; 

 corolla greenish-purple, one fourth as long as the pedicels ; leaves of the cro^vn 

 pale purple, ovate, obtuse, longer than the incurved horn ; follicle ovate-oblong, 

 woolly,>armed with soft spines. (A. Syriaca, L.) — Fields and road-sides. New 

 Berne, North Carolina, Croom, and northward. June and July. — Stem 3° -4° 

 high, sometimes branched. Leaves 4' - 8' long. Pedicels 1' - 1-^' long, purplish. 

 Corolla J' wide. 



* * Follicles spineless. 

 ■I— Leaves opposite, oval or oblong, narrowed into a pet'.olc. 



2. A. phytolaeeoides, Pursh. Stem tall, smooth; leaves ovate or 

 ovate-lanceolate, tapering at each end, paler and minutely pubescent beneath, 

 membranaceous ; umbels long-peduneled, manj'-flowcred j pedicels filiform, 

 drooping, nearly as long as the peduncle ; corolla pale greenish ; leaves of the 

 crown white, truncated, 2-toothed, shorter than the subulate incurved horn. — 

 Low grounds along the mountains, and northward. June and July. — Stem 3° - 

 5° high. Leaves 6' - 9' long. Pedicels 2' -3' long. 



3. A. purpurascens, L. Stem smooth ; leaves ovate-oblong, acute, 

 short-petioled, paler and pubescent beneath ; umbels 1-2, terminal, peduncled, 

 many-flowered ; pedicels half as long as the peduncle, and twice as long as the 

 dark purple corolla ; leaves of the crown oblong, abruptly contracted above, 

 twice as long as the incurved horn and nearly sessile gynostegium. — Thickets 

 and borders of woods, Tennessee, North Carolina, and northward. June and 

 July. — Stem 2°-3° high. Leaves 4'-"' long. Pedicels 9"-15'' long, pu- 

 bescent. 



4. A. variegata, L. Stem stout, leafless below, pubescent in lines ; leaves 

 oval, oblong, or obovate, cuspidate, smooth on both sides ; umbels 3-5, pubes- 

 cent, closely flowered, the upper ones corymbose ; pedicels erect, as long as the 

 peduncle ; corolla white ; leaves of the crown roundisli, longer than the purplish 

 gynostegium, equalling the thick awl-pointed incurved horn. (A. nivea, Pursh.) 

 — Dry open woods and borders of fields, Florida to Mississippi, and northward. 

 May and .June, — Stem 2° - 3° high, purplish. Leaves rather thick, 2' - 3' long 

 Peduncles 9" - 12" long. 



