Vol. III.] 



MILKWEED FAMILY. 



17 



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

 [Gonolobus Michx. Fl. Bor. Am. 1: 119. 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, 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 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 75 species, natives of America. Besides the following, some 10 others occur in the 

 southern and southwestern United States. 

 Crown annular, io-crenate; follicles angled, not wart}-. 

 Corolla about twice as long as the calyx. 

 Corolla 3-4 times as long as the calyx. 

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

 Flowers purple to dull yellow. 



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

 Corolla-segments linear or linear-oblong, 5" -7" long. 

 Crown merely crenate. 

 Crown toothed or lobed. 



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

 Crown 10-toothed, the alternate teeth thinner and longer. 

 Flowers white. 



4- 



5- 

 6. 



V. suberosum. 

 V. gonocarpos. 



V. hirsutum. 

 V. obliquum. 



V. Carolinense. 



V. Shortii. 



V. Baldwinianum. 



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. 1S11. 



V. 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 

 Yz'-i' long; cymes commonly few-flowered; pe- 

 duncles X /-l/ l n g pedicels 'y^'-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 annular fleshy undulately io-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. 



2. Vincetoxicum gonocarpos Walt. 

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



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

 G. macrophyllus Michx. Fl. Bor. Am. 1: 119. 1803. 

 Gonolobus laevis var. mac?'Ophyllus 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 i / -4 / long; cymes few-flowered; 

 peduncles 1 '-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 alow obtusely undulate disk; follicles 

 glabrous, similar to those of the preceding species 

 but usually shorter. 



Along rivers and in moist thickets, Virginia to South 

 Carolina, west to Indiana, Missouri and Texas. 



