344 ASCLEPIADACE^E. (MILKWEED FAMILY.) 



5. VINCETOXICUM, Moench. 



Calyx 5-parted. Corolla 5-parted, wheel-shaped. Crown flat and fleshy, 

 disk-like, 5 - 10-lobed, simple. Anthers, smooth follicles and seeds much as in 

 Asclepias. Herbs, often twining. (Name from vincens, binding, and toxicum, 

 poison.) 



V. NIGRTM, Moeuch. More or less twining, nearly smooth ; leaves ovate 

 or lance-ovate ; flowers small, dark purple, in an axillary cluster, on a peduncle 

 shorter than the leaves. N. Eug. to Peun.; a weed- escaping from gardens. 

 (Adv. from Eu.) 



6. GONOLOBUS, Michx. 



Calvx 5-parted. Corolla 5-parted, wheel shaped, sometimes reflexed-spread- 

 ing ; the lobes convolute in the bud. Crown small and fleshy, annular or cup- 

 shaped, in the throat of the corolla. Anthers horizontal, partly hidden under 

 the flattened stigma, opening transversely. Pollen-masses 5 pairs, horizontal. 

 Eollicles turgid, mostly muricate with soft warty projections, sometimes ribbed. 

 Seeds with a coma. Twining herbs or shrubs (ours herbaceous), with oppo- 

 site heart-shaped leaves, and corymbose-umbelled greenish or dark purple 

 flowers, on peduncles rising from between the petioles. Our species belong to 

 the typical section, with the crown simple and uuappeudaged, and the corolla 

 nearlv veinless. (Name composed of ycavia, an angle, and AojSos, a pod, from 

 the angled follicles of some species.) 



* Crown a low undulately IQ-lobed fleshy disk ; follicles unarmed, glabrous, 3 - 5- 



costate or angled. 



1. G. Suber6sus, R.Br. Leaves cordate with an open shallow or some- 

 times deeper and narrow sinus, pointed, glabrate or hairy (3 -5' long) ; umbels 

 3 - 9-flowered, much shorter than the petiole; corolla broadly conical in bud, 

 abruptly pointed, ticisted ; lobes ovate or triangular-lanceolate, acute, pubescent 

 inside; rnly.c half as long. (G. macrophyllus, Chapman.) Near the coast, 

 Va. to Fla, 



2. G. laevis, Michx. Leaves oblong-cordate with a deep and narrow open 

 sinus, conspicuously acuminate (3-6' long); umbels 5- 10-flowered, barely 

 equalling the petiole ; corolla elongated-conical in bud, not twisted ; lobes nar- 

 rowly or linear-lnncfo'dtc, obtuse, glabrous inside, 3-4 times as long as the calyx. 

 South of our range. Passes into var. MACROPHYLLUS, Gray, with larger 

 broadly cordate leaves, the sinus often closed, finely pubescent beneath. (G. 

 macrophyllus, Michx.) River-banks, Va. to S. Ind., Mo., S. C., and Tex. 



* * Crown cup-shaped , as high as the anthers; follicles muricate, not costate. 

 -t- C'roirn fleshy, merely 10-crenate, or the crenattires bidentatc. 



3. G. obliquus, R. Br. Leaves rounded- to ovate-cordate with a narrow 

 sinus, abruptly acuminate (3-8' long); umbel many-flowered; corolla in bud 

 oblong-conical; its lobes linear-ligulate (5-6" long, 1" wide), crimson-purple 

 inside, dull or greenish and minutely pubescent outside. River-banks, moun- 

 tains of Penn. and Va., to Ohio and Mo. Flowers said to be fragrant. 



4. G. hirsiltus, Michx. Commonly more hairy ; leaves with the basal 

 lobes sometimes overlapping ; peduncles fewer-flowered ; corolla in bud orate, 

 its lobes elliptical-oblong (3-4" long), barely pubcrulent outside, dull or brownish- 

 purple. Md. and Va. to Tenn. and Fla. 



