PENTANDRIA. DIgTNIA. 163 



depressed, exactly equal with the antheri- 

 dium (antheroid cells) discoid, pentangular, 

 without alated lateral margins or terminal mem- 

 branaceous cusps. Pollinia (masses of pollen) 

 5 pair, even, transverse. Follicles 2. Seed co- 

 mose. 



Herbaceous and twining plants, with opposite leaves; 

 flowers axillary, umbellate. Nearly allied to Cynanchum 

 in some respects; and particularly to the North Ameri- 

 can species, but very distinct in the parts of fructifica- 

 tion, having a depressed or discoid antheridium, with- 

 out either lateral or terminal produced margins, and re- 

 ceiving the pollinia transverse!) , but still attached as is 

 usual in Cynanchum and Asclepiast by pairs to the upper 

 angles of the stigma. 



Species. 1. G. macrophyllus. 2. hirsiitus. Flowers 

 brown, segments of the corolla linear-oblong, follicles 

 muricate, \\ithsoft spines; the whole plant pubescent; sar- 

 ments and petioles hirsute ly hairy; leases cordate-oval, 

 distinctly acuminate. 3. carolinensis. Stem twining and 

 with the petioles hirsutely hairy, the whole plant pubescent; 

 leaves ovate-cordate, acute, somewhat acuminate; seg- 

 ments of the corolla ovate-olatuse; flowers yellowish, um- 

 bellate. — The leaves are not hirsute but covered on both 

 sides with a minute pubescence. Pollinia t.fknsverse It 

 is nearly allied to the preceding, but very distinct in the 

 flower; with the fruit lam unacquainted.— In the vicinity 

 of >avannah. — JJr. Baldivyn. 



4.* viridijiorns. Eveiy where smooth; stem twining; 

 leaves subrenifor'n-cordate, acuminate upon longish pe- 

 tioles, base auriculate; segments of the corolla Unear- 

 oblong, oblique, obtuse, greenish follicles ribbed. Hab. 

 On the banks of the Mississippi, near St. Louis, £cc, 

 V. s. In Herb. amberL. london. 



Hitherto an American genus. 



241. CYNANCHLM. Z. (Dog's-bane.) 



Calix 5-toothed, very small, and persistent. 

 Corolla rotate. Lepanthium simple, cylindric, 

 « 5 to 20-lobed," (R. Br(.wn,) siirrounf'ing the 

 orifice of the tube. Stamina as in Asdepias, 



[ Stigmata 2. Follicles 2. Seed comose. 



Habit similar to Gonolobus, but many of the species 

 are shrubby. 



