Vol.. III.] 



MILKWEED FAMILY. 



17 



6. VINCETOXICUM Walt. Fl. Car. 104. 1788. 

 [GoxoLoiiUS Michx. Fl. Bor. Am. i: ng. 1803.] 

 Twining or trailing perennial vines, with opposite usually cordate leaves, and rather 

 large purple brown white or greenish flowers in axillary umbel-like cymes 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, lobcd or divided, adnatc 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 trans- 

 versely dehiscent. Pollen-masses solitary in each sac, horizontal or nearly so. Follicles 

 thick, acuminate, smooth, angled or tuberculate. Seeds comose. [Greek, subduing 

 poison.] 



About 7=, species, natives of America. Besides the following, some 10 others occur in the 

 southern and southwestern Vnited States. 

 Crown annular, lo-crenate; follicles angled, not warty. 

 Corolla about twice as long as the calyx. 

 Corolla 3-4 times as long as llie calyx. 

 Crown cup-shaped, about as high as the anthers; follicles warty. 

 Flowers purple to dull yellow. 



Corolla-segments oblong, 3"-4" long. 

 Corolla-segments linear or linear-oblong, s"-y" long. 

 Crown merely crenate. 

 Crown toothed or lobed. 



Crown 5-lobed, with a subulate 2-cleft tooth in each sinus. 

 Crown lo-toothed, the alternate teeth thinner and longer. 



V. suberosum. 

 V. gonocarpos. 



V. hirsHlum. 

 V. obliquum. 



V. Carolinense. 



V. Shortii. 



V. Bald'u'inianum. 



Flowers white. 



I. Vincetoxicum suberosum (L.) Britton. Coast Vincetoxicum. (Fig. 2931.) 



Cynanchum suberosum L. Sp. PI. 212. 1753. 



G. suberosus R. Br. in Ait. Hort. Kew. Ed. 2: 82. 181 1. 



f^. suberosum Britton, Mem. Torr. Club, 5: 266. 1894. 



Stem pubescent or glabrous, slender, twining. 

 Leaves thin, 2^-5' long, i'-3' wide, ovate or ovate- 

 oval, acute or abruptly acuminate at the apex, cor- 

 date at the base, the sinus shallow, open; petioles 

 yi'-l' long; cymes commonly few-flowered; pe- 

 duncles ^i'-i' long; pedicels Yz'-i' long, fleshy, 

 nearly glabrous; corolla brown-purple, broadly 

 conic in the bud, its segments lanceolate or ovate- 

 lanceolate, acute, pubescent or granulose within, 

 3"-4" long, about twice as long as the calyx; 

 crown an an nular fleshy undulately lo-crcnate disk ; 

 follicles glabrous, 3-5-angled, when young fleshy, 

 when mature dry and spongy, 4'-6' long, \' in 

 diameter or more. 



In thickets, Virginia to Florida, mainly near the 

 coast. May-July. 



2. Vincetoxicum gonocarpos Walt. 

 Large-leaved Angle-pod. (Fig. 2932.) 



Vincetoxicum gonocarpos Walt. Fl. Car. 104. 1788. 

 C macropliylhts Michx. Fl. Bor. Am. i: iig. 1803. 

 Gonolobus laevis var. macrophyllus A. Gray, Syn. Fl. 

 2: Part i, 103. i.SyS. 



Glabrous or pubescent, stems slender, climbing 

 high. Leaves broadly ovate, thin, 3'-S' long, 2'-5'' 

 •wide, acuminate at the apex, deeply cordate at the 

 base, the sinus narrow or the rounded auricles over- 

 lapping; petioles i'-4' long; cymes few-flowered; 

 peduncles i'-3'long; pedicels rather stout, glabrous 

 or nearly so; corolla conic in the bud, its segments 

 lanceolate, 4"-5" long, 3-4 times as long as the 

 calyx; crown a low obtusely undulate disk; follicles 

 glabrous, similar to those of the preceding species 

 but usually shorter. 



.\long rivers and in moist thickets, Virginia to South 

 Carolina, west to Indiana, Missouri and Texas. 



