CLASS V. ORDER II. 109 



At the top of the wings of the anthers are five rainute black cor- 

 puscles, which, being drawn out with a pin, bring with them 

 pairs of yellow, narrow obovate pollen masses. — Low grounds. — 

 June. — Perennial. 



AscLEPiAs PURPURASCENs. L. Dark flowcred Silk Weed. 

 Stem nearly simple ; leaves ovate, hairy beneath ; 

 corymbs erect; horns of the nectary resupinate. 



This species is well defined by the peculiar curvature of the 

 horn. Stem erect, smooth, with a barely perceptible down, 

 slightly branched at top, three or four feet high. Leaves oppo- 

 site, glabrous above, paler and downy beneath, the midrib purple 

 above. Umbels terminal, on stout footstalks with flowers about 

 the size of A. Syriaca. Calyx small, very acute. Corolla re- 

 flexed, acute, of a dark crimson purple, sometimes lighter if the 

 plant grows in the sun. Nectaries of the same color, truncated 

 very obliquely inward, the horns bent inward at a right angle so 

 close to the stigma that they appear at first view to be wanting. 

 Mass of anthers greenish, variegated with brown, and about half 

 as long as the nectaries. — In different soils, Cambridge, Newton, 

 rare. — July. — Perennial. 



AscLEPiAs PULciiRA. WHId. Watet' Silk weed. 



Leaves lanceolate, pnbescent underneath ; stem 



divided toward the top; umbels erect, in pairs. 

 Willd. 



Common in wet ground, by the sides of ponds, &c. Stems 

 commonly in bunches, erect, downy, subdivided near the top. 

 Leaves lanceolate, tapering to a very acute point, sometimes 

 hairy on both sides, as is also the stem. Umbels many, small, 

 on downy peduncles. Involucre many leaved, deciduoi>s. — 

 Flowers small, half the size of A. Syriaca. Corolla crimson- 

 purple, acute. Nectaries paler, truncated obliquely iuAvards, 

 almost to their base ; horns erect incurved. Mass of anthers 

 greenish, as long as the nectaries ; stigma whitish. Flowers 

 purple. — July. — Perennial. 



The bark is very strong and fibrous. 

 10 



