38 . ASCLEPIADACEAE. ~ Vor. IIL. 
3. Vincetoxicum hirsitum (Michx.) Britton. 
Hairy Vincetoxicum. Fig. 3418. 
Gonolobus hirsutus Michx. Fl. Bor. Am, 1: 119. 1803. 
V. hirsutum Britton, Mem, Torr, Club 5: 266. 1804. 
Stem downy, slender. Leaves ovate, acuminate at 
the apex, deeply cordate at the base, downy, 2’-4’ 
long, 17-23’ wide, the sinus narrow, or the lobes 
sometimes overlapping; petioles slender, pubescent, 
’-2’ long; peduncles usually about equalling the 
petioles, sometimes longer; umbels few-several- 
flowered; corolla brown-purple to greenish yellow, 
ovoid in the bud, its segments oblong, very obtuse, 
3-4” long, minutely puberulent without, about 4 
times as long as the densely pubescent calyx; crown 
cup-shaped, fleshy, about as high as the anthers, the 
margin Io-crenate; follicles: lanceolate, 3’-5’ long, 
muricate, puberulent; seeds entire. 
In thickets, Maryland to Florida, west to Tennessee. 
Running milkweed. Negro-vine. July—Aug. 
Fig. 3419. 
Cynanchum hirtum L. Sp. Pl. 212. 1753? 
Cynanchum obliquum Jacq, Coll. 1: 148, 1786. 
G. obliquus R. Br.; R. & S. Syst. 6: 64. 1820. 
V. obliquum Britton, Mem. Torr. Club 5: 266. 1804. 
Stem puberulent or hirsute, slender. Leaves 
pubescent, broadly ovate, short-acuminate at the 
apex, deeply cordate at the base with an open or 
closed sinus, 2’-8’ long, 13-6’ wide; petioles 
rather stout, pubescent, 1-4’ long; umbels slen- 
der-peduncled, few-several-flowered; pedicels very 
slender, 1’-2’ iong; corolla narrowly conic in the 
bud, red-purple within, greenish and minutely 
pubescent without, its segments elongated-linear, 
obtuse, 6-7 times as long as the hirsute calyx; 
crown cup-shaped, as high as the anthers, fleshy, 
its margin 1o-crenulate, the intermediate crenu- 
lations sometimes 2-dentate; follicles ovoid-lan- 
ceolate, 2’-3’ long, muricate. 
In thickets, Pennsylvania to Ohio, Missouri, Vir- 
ginia and Kentucky. July—Aug. 
as 
‘ P a) : 
5. Vincetoxicum carolinénse (Jacq.) Britton. 
Carolina Vincetoxicum. Fig. 3420. 
Cynanchum carolinense Jacq. Coll. 2: 228. 1788. 
G. carolinensis R. Br.; R. & S. Syst. 6: 62, 1820, 
V. carolinense Britton, Mem. Torr. Club 5: 265. 1804. 
Stem hirsute. Leaves broadly ovate, acute or 
short-acuminate at the apex, deeply cordate at the 
base with a narrow or closed sinus, 3’-7’ long, 2’-53’ 
wide, pubescent, at least beneath; petioles hirsute, 
14-4’ long; peduncles 2’-4’ long; pedicels very slen- 
der, 1’ long or more; corolla brown-purple, oblong- 
conic in the bud, puberulent without, its segments 
linear-oblong or linear-lanceolate, obtusish, 5”-6” 
long, 5-6 times longer than the hirsute calyx; crown 
cup-shaped, scarcely fleshy, 5-lobed, with a subulate 
longer 2-cleft erect tooth in each sinus; follicles 
muricate. 
_ In thickets, Virginia to Missouri, south to South Caro- 
lina and Louisiana, May-July. 
