166 PENTANDRIA. DIGYNIA. 



ous, sessile, angles opening by 5 longitudinal 

 clunks. Fo/Hc/es 2, ventricose, acuminate, smooth 

 or mu!'i( ate. Seed comose. 



Shrubby or herbaceous, stems erect; leaves opposite, or 

 alternate, rarely verticiUate; peduncles axillary and termi- 

 nal, solitary; flowers in unnbelis, numerous. — Antheridiiim 

 (antheroid cells, anthers, ofsome) conlc-cylindric, (resem- 

 bling- the 5 united anthers in Syngenesious florets,) sessile 

 or subsessile, crustaceous, separable only by five longitudi- 

 nal chinks, into 5 lobes, connected to the stigma both above 

 and below, lobes antheroid, 2-celled, cells open, margin 

 reflected, salient, terminating above in membranaceous 

 ovate cusps. PoUinia (concrete masses of pollen) 5 pair, 

 even, suspended from the angles of the stigma, clavate, 

 compressed, diaphanous, solid and concrete, of a yellow, 

 uaxy substance, united together by a small, black, cloven 

 tubercle; alternating in the cells of the antheridium, each 

 pair being common to 2 lobes. Style none. Stigma dis- 

 coid, pentagonal. Follicles smooth, or muricated with 

 soft and flexible spines (as in A. syrioca, &.c.) Seeds 

 pendulous by the coma, obtusely obovate and compressed, 

 or subelliptic, surrounded by a double winged margin; 

 perisperm thin and carnose; embryon flat; radicle in- 

 verted. Receptacle free, with lateral, imbricated, longi- 

 tudinal lamella for the reception of the serpjnal coma. — The 

 flowers of the larger species of this genus have the pro- 

 perty of meclianically detaining small insects. The Mus- 

 ca (iomestica or common house-fly is in general the subject 

 of this cruel accident, and may frequently be seen tor- 

 tured by the flowers of Asclepias si/riaca, and A. in- 

 carnata; they are uniformly held by the tarsi, which 

 get hooked into the minute cliink existing in the con- 

 necting tubercle or clasp of llie polUnium. — All the spe- 

 cies of this genus afford a silky flax, and generally a lac- 

 tescent sap. 



f Leaves opposite. 



Species. l.A.syriaca. Lepanthium bidentate. Follicles 

 muricate. 2. phytolaccoides. Lepanthium truncate, internal 

 margin bidentate; petals pale green, lepanthium whitish, 

 umbels both lateral and terminal. — New York to Carolina, 

 and on the banks of the Ohio. Near Philadelphia on the 

 rocky banks of Wishahikon creek. 3. debilis. 4. par- 

 Tiflora. S.nirea. 6. incmmata. T.atnoena. Leaf oblong- 

 ova I, with an acute point, under side minutely pubescent, 

 petiole very short; umbells terminal, erect; flowers pur- 

 ple; segments of the lepanthium ovate-oblong, entire, twice 

 the length of the antheridium, central process flattened 



