GENus 6. MILKWEED FAMILY. 37 
6. VINCETOXICUM Walt. Fl. Car. 104. 1788. 
Twining or trailing perennial vines, with opposite usually cordate leaves, and rather large 
purple, brown, white or greenish flowers in axillary cyme-like umbels or fascicles. Calyx 
5-parted or deeply 5-cleft, mostly 5-glandular within. Corolla rotate, very deeply 5-parted, 
the tube very short, the segments convolute in the bud. Corona (crown) annular or cup- 
shaped, entire, lobed or divided, adnate to the corolla. Stamens inserted on the base of the 
corolla, the filaments connate into a tube; anthers not appendaged, merely tipped, borne along 
or just under the margin of the flat-topped stigma, the sacs more or less transversely dehis- 
cent. Pollen-masses solitary in each sac, horizontal or nearly so. Follicles thick, acuminate, 
smooth, angled or tuberculate. Seeds comose. [Greek, subduing poison.] 
About 75 species, natives of America. Besides the following, some to others occur in the 
southern and southwestern United States. Type species: Vincetoxicum gonocarpos Walt. 
Crown annular, ro-crenate; follicles angled, not warty. 
Corolla about twice as long as the calyx. 1. V. suberosum, 
Corolla 3-4 times as long as the calyx. 2. V. gonocarpos, 
Crown cup-shaped, about as high as the anthers; follicles warty. 
Flowers purple to dull yellow. 
Corolla-segments oblong, 3”-4” long; crown crenate. 3. V. hirsutum, 
Corolla-segments linear or linear-oblong, 5”-7” long. 
Crown merely crenate. 4. V. obliquum, 
Crown toothed or lobed. 
Crown 5-lobed, with a subulate 2-cleft tooth in each sinus, 5. V.carolinense, 
Crown 1o-toothed, the alternate teeth thinner and longer. 6. V. Shortti, 
Flowers white ; crown deeply cleft. 7. V. Baldwinianum. 
1. Vincetoxicum suberésum (L.) Britton. Coast Vincetoxicum. Fig. 3416. 
Cynanchum suberosum L. Sp. Pl. 212. 1753. 
G. suberosus R, Br. in Ait. Hort. Kew. Ed. 2: 82. 1811. 
V. suberosum Britton, Mem, Torr. Club 5: 266. 1894. 
Stem pubescent or glabrous, slender, twining. 
Leaves thin, 2’-5’ long, 1’-3” wide, ovate or ovate- 
oval, acute or abruptly acuminate at the apex, cor- 
date at the base; petioles 4’-2’ long; umbels com- 
monly few-flowered; peduncles 4-1’ long; pedicels 
#-1’ long, fleshy, nearly glabrous; corolla brown- 
purple, broadly conic in the twisted bud, its segments 
lanceolate or ovate-lanceolate, acute, pubescent or 
granulose within, 3-4” long, about twice as long as 
the calyx; crown an annular fleshy undulately 
to-crenate disk; follicles glabrous, 3-5-angled, when 
young fleshy, when mature dry and spongy, 4’-6’ 
long, 1’ in diameter or more. ~ 
In thickets, Virginia to Florida, mainly near the coast. 
May-July. 
ae |) 
2. Vincetoxicum gonocarpos Walt. Large- 
leaved Angle-pod. Fig. 3417. 
Vincetoxicum gonocarpos Walt. Fl. Car. 104, 1788. 
G. macrophyllus Michx. Fl. Bor, Am. 1: 119. 1803. 
Gonolobus laevis var. macrophyllus A, Gray, Syn. Fl. 2: 
Part 1, 103. 1878, 
Glabrous or pubescent, stems slender, climbing 
high. Leaves broadly ovate, thin, 3’-8’ long, 2’-6’ 
wide, acuminate at the apex, deeply cordate at the 
base, the sinus narrow or the rounded auricles over- 
lapping; petioles 1-4’ long; umbels few-flowered; 
peduncles 17-3’ long; pedicels rather stout, glabrous 
or nearly so; corolla conic in the bud, not twisted, its 
segments lanceolate, glabrous, 4”-5” long, 3-4 times 
as long as the calyx; crown a low obtusely undulate 
disk; follicles glabrous, sim:lar to those of the pre- 
ceding species but usually shorter. 
Along rivers and in moist thickets, Virginia to South 
Carolina, Georgia, Indiana Missouri and Texas. 
