r>8:j PENTANDRIA, DiGYNIA. asclepias. 



Stem 2 — 3 feet high, tomentose-pubescent, with a few upright, 

 opposite, or alternate branches towards the summit. Leaves 

 about 3 inches long, acute, cordate at the base ; petiole one- 

 fourth of an inch long. Umbels terminal, numerous, crowded ; 

 pedicels three-fourths of an inch long. Corolla pale purple. 

 Leaflets of the nectary as long as the anthefidiumy obliquely 

 truncate, not dentate ; Aorn subulate. Follicles %moo\h. 



Hab. In swamps and on the banks of rivers. August. 



iS. ptilchra P e r s. : stem and leaves very hairy, A. pul- 

 •chra Will d. Spec. I. p. 12Q7. B ig. Bost. ip. 63, Roem. 

 ir Schult. VI. p. 72. 



Hab. With the preceding; from which, as Purs h remarks, 

 it does not differ, except in the degree of pubescence. 



7. A. amccna L. ; stem with 2 longitudinal pubescent 

 lines ; leaves subsessile, oblong-oval, pubescent beneath ; um- 

 bels terminal, erect; nectary entire; horn subulate, ex- 

 serted. W illd. Spec, l.^, \'2<jb. M ich. Fl. I. ip. 118. 

 Pursh Fl.l. p. ISV- ^utLGcn.l.^.166. Roem. 

 k Schult. V. p. 73. 



Stem about G feet high, erect, branched above, nearly smooth, 

 with 2 conspicuous pubescent lines. Leaves 3 — 4 inches long, 

 acute or acuminate, smooth above, a little pubescent beneath ; 

 petiole very short. Umbels numerous, many-flowered ; fiedi- 

 eels pubescent. Corolla purple. Sectary rose-coloured; 

 leaflets ovate, obtuse, entire, longer than the antheridium; horn 

 subulate, flattened towards the base. Follicles slightly ventri- 

 cose, smooth. 



Hab. In swamps and overflowed meadows. July — August. 



8. A. purpurascens L. : stem simple ; leaves ovate, vil- 

 lous beneath ; umbels erect ; leaflets of the nectary resupinate. 

 Wil Id. Spec. l. p. 1-265. P ur s h Fl. I. p. ]S\. Big. 

 Bost, p. 62. El Hot I Sk. I. p. 322. Dill. Elth. t. 28. 

 f. 31. R em. k Schult. \[. 1^.13. 



Stem erect, about a foot and a half long, somewhat hairy towards 

 the top. Leaves on short petioles, a little pubescent above, 

 whitish beneath; midrib broad, purple. Flowers purple.^ 

 Dill. 



Hab. Near Boston. Bigelow. In New-York. Muhlen- 

 berg. 



I have never seen a North-American Asclepias in which 

 the nectary was resupinate. Perhaps the plant of Dille- 

 nius is only a variety of A. amccna or incarnata. 



9. A. debilis M i c h. : very smooth ; stem erect, weak,, 

 simple; leaves petiolate, oval-lanceolate, acute at each extre- 

 mity, membranaceous; umbels terminal, loose; pedicels ca- 

 pillary. Mich. Fl. I. p. 116. Piirsh Fl. I. p. 180. 



