t 



3IILKWEED FAMILY. 263 



2. A, tubero'sa, L. Hirsute ; not lactescent ; stem ascending, divari- 

 cately branched at summit, leafy ; leaves oblong-lanceolate or linear- 

 obloDg, mostly alternate-scattered, lowest opposite, subsessile ; umbels 

 numerous, lateral and terminal, often forming a spreading corymb. 



Tuberous Asclepias. Butterfly-weed. Pleurisy-root. 



TThole plant mostly very hairy. Root perennial ; large, tuberous. Stem about 2 feet 

 high, generally more or less oblique or leaning ; branches spreading and often recurved, 

 ieares 2 - 4 inches long, and half an inch to an inch wide, scattered or rarely opposite, 

 varying from lance-hnear to oblong and oblanceolate, acute or obtuse, mostly obtuse at 

 base, on very short petioles. Stamineal crown bright orange color, — the hoods erect, 

 lance-oblong, distinct, abruptly narrowed below, the infolded margins with each an obtuse 

 tooth near the base ; horns subterete, tapering to a point, incurved. Follicles about 4 

 inche.s long, somewhat veutricose, acuminate, tomentose-pubescent. 



Old fields, pastures and fence-rows : throughout the United States, J^Z. July -August. 

 Fr. Sept. -October. 



Ohs. This is inclined to make its appearance in our cultivated grounds, 

 or pasture fields ; and, though a rough, coarse weed, is not a troublesome 

 one. When in bloom, the bright orange-colored umbels of this species 

 are quite showy. The root once had a reputation for being medicinal ; 

 but it is now generally neglected. 



2. ENSLEN'IA, Nutt. Enslenia. 



[Dedicated to Erulen, an Austrian botanist, who collected in the Southern States early in 

 the present century.] 



Calyx 5-parted. Corolla 5-parted ; the divisions erect, ovate-lanceolate. 

 Croum of 5 free membranaceous leaflets, which are truncate or obscurely 

 lobed at the apex, where they have a pair of flexuous awns united at 

 their base. Anthers nearly as in Asclepias ; pollen-masses oblong, obtuse 

 at both ends, fixed below the summit of the stigma to the descending 

 glands. Pods oblong-lanceolate, smooth. Seeds with a tuft as in Ascle- 

 pias. Perennial twining herbs. 



1. E. al'bida, Nutt. Leaves opposite, ovate-heart-shaped, acute, long- 

 petioled ; flowers small, in raceme-like clusters on slender axillary pe- 

 duncles. 



Whitish Enslenia. 



stem 8-12 feet high, climbing, slightly pubescent or smooth. Leaves 3-5 inches long 

 and al)out the same in width, with a broad sinus at base, somewhat pubescent on the 

 nerves below ; petiole equalling or exceeding the blade in length. Peduncles about half an 

 inch long, sometimes several from the same axils ; flowers greenish or yellowish-white, 

 sweet-scented, on pedicels about their own length. 



Alluvial .soil. West and Southwest. July - September- 



Obs. This plant is introduced on account of the statement of Doctor 

 Short, the distinguished botanist, of Kentucky, who says that it is a 

 ■great nuisance on the farms along the Ohio river. We are not informed 

 whether it has acquired a popular name. * 



