Botany of Illinois and Missouri. 173 
fleshy, somewhat pubescent beneath, ciliate on the margin. 
Flowers white and pale red. . 
Asclepias incarnata Lin, ica 
Stem branched above. Leaves 3—5 inches in length, 
smooth, lanceolate-oblong, cordate at base, on short petioles. 
Umbels numerous. Flowers purple. 
Has. Wet prairies and exsiceated ponds. July—Aug. 
Asclepias amoena L722. 
Stem sparingly branched above. Leaves oblong, tapering 
at base, acute or acuminate, whitish pubescent beneath. 
bels few. 
Has. In similar situations with the last—July. 
;, __ Asclepias verticillata Lin. 
Leaves varying from 1 to 3 inches in length, and from 2 te 
4 lines in width. Umbels verticillate towards the upper part. 
Flowers purple. ’ 
Has. iri 
Prairies and barrens near St. Louis—July. 
Asclepias obtusifolia Mich. 
Haz. Open prairies west of St. Louis. . The 
whole plant, and particularly the flowers, are larger than on 
the sea coast. 
Asclepias longifolia Mic h. 
Stem 2 to 3 feet high, erect, simple, very hairy, Leaves 
8 to 4 inches long, scattered, narrow-lanceolate, obtuse, 
thick, scabrous, covered on both sides with short stiff hairs, 
revolute on the margins. _ Umbels lateral, on short peduncles. 
Pedicels very numerous, hairy. £ 
shorter than the antheridium, distinetly cucullate ; horn want- 
ing. Corol green. 
Har. On the Prairies near St. Louis, and St. Charles. 
June. 
This plant belongs to the genus Acerates of Elliott ; 
which differs from _Asclepias principally in the absence of the 
horn-like processes of the ae But this —— = 
s to be common to several genuine species of Asclepos ; 
att api tice; A. phytolaccoides, &§c. Mr. Nuttall and =a 
Torrey seem to think that A. longa olia is not specifically 
distinct from A. viridiflora of Pursh. 1 have only @ single 
