rSNTAXDRIA. DIGTNIA. 165 



A genus approaclilng- Ct/tianchum and Asdepias. 



Stem herbaceous, twining, leaves opposite; tiowers axil- 

 lary, corymbose. 



E. atbida. 



Descriptiox. Root perennial. Stem herbaceous, twin- 

 ing, n^arked with an alternating pubescent Ijne. Leaves 

 opposite, smooth, cordate-ovaie, acute, somewhat acumi- 

 nate, sinuate at the biise, sligh ly pubescent on the mar- 

 gin, and sometimes along the nerves, from 1 to 2 inches 

 long, and 1 to 2 wide, petiole about an inch. Corymbs 

 axillar}-, many flowered, upon long peduncles, several 

 often from the same axill; pedicells and calix pubescent. 

 Calix 5-parted, segments lanceolate-ovate. Corolla 5- 

 parted, greenish or yellowish-white, divisions connivent, 

 erect, linear oblong, somewhat obtuse. Lepanthium (nec- 

 tary, L.) 5.parted,^petaloid, segments divided down to the 

 base, flat, oblong, and truncated, sometimes 4-toothed, 

 the 2 central dentures or incisions terminating in filiform 

 awns. I'ollinia (masses of pollen) 5 pair, pendulous, and 

 even as in Asdepias, suspended to the angles of the stig- 

 ma, cylindric-oblong, much sliorter tlian the antheri- 

 dium, diaplianous, above united together by a small black 

 cloven tubercle, alternating in the antheroid cells, each 

 pair being common to 2 antheroid bodies. Antheridium 

 (antheroid bodies) short and crustaceous, with salient 

 margins, each lobe terminated by a broad, ovate, white, 

 chaffy cusp. Style none. Stigma conic, subbilamellate, 

 seated upon the disk of the antheridium. Follicles 2, 

 short, ovate? not more than a few lines long? seed comose? 



Habitat. Near Shepherdstown, on the gravelly banks 

 of the Potomac, Virginia. Abundant in certain localities, 

 on the high sandy banks of the river Scioto, &.c. also near 

 Cincinnati, (Ohio) ascending to the height of 8 or 12 feet. 

 Flowering in July and August. An occidental plant, or 

 confined to the vrestern side of the Alleghany mountains, 

 always on alluvial soil. Flowers ochrof ucous, with a 

 melliferous scent. Stem like most of the Apocine.e, 

 aflbrding flax. 



243. ASCLKPIAS. L. (Wild-Cotton, Swallow- 

 wort.) 



Calix small, S-parted, persistent. Corolla 

 rotate, tnostly reflected. Lepanthium (nectary, 

 L.) simple, 5-parted, segments ovate, cucullate, 

 eacii producing from ifs base an interna! subulato 

 averted awn. Jinthmdinm 5-parted^ cruslac«- 



