454 



MEDICAL BOTANY. 



creases the appetite, acts as a diuretic, and improves the general health. It 

 has also been administered with advantage in venereal complaints, and in fact 

 in all those disordered conditions of the system in which sarsaparilla has 

 been found beneficial. It is given in infusion, decoction, or extract, both of 

 which forms are objectionable, as the volatile active principle is partly driven 

 off. The syrup has been found advantageous, the best method of making 

 which has been given by Mr. Bell, in the Lond. JPharm. Journ. (Am. Journ. 

 Pharm., ix. 298.) 



Asclepias. — Linn. 



Calyx 5-parted. Segments small, ovate, spreading. Corolla deeply 5-clefl, mostly re- 

 flected. Stamineal crown 5-leaved, leaflets cucullate, opposite the anthers, with a subu- 

 late everted process at base. Pollen masses .com pressed, attached by a narrow apex, and 

 pendulous. Stigma depressed, mutic. Follicles ventricose, acuminate, smooth or muri- 

 cate. Seeds comose. 



A genus of about fifty species, principally of North American herbaceous 

 perennials, with opposite, verticillate, rarely alternate leaves. All the species 

 afford a silky flax, and most generally abound in a lactescent juice. 



A. tuberosa, Linn, — Stem erect, hairy, with spreading branches. "Leaves oblong, lan- 

 ceolate, sessile. Umbels numerous, terminal. 



Linn., Sp. PL, 316; Bigelow, Am. Med. Bot., ii. 59; Barton, Veg. 

 Mat. Med., i. 239 ; Rafinesque, Med. Fl, i. 74 ; Lindley, Med. Flor. 529. 

 Common Names. — Butterfly Weed ; Pleurisy Root ; Wind Root, &c. 



Description. — Root peren- 



Fig. 203. 



A. tuberosa. 



nial, large, fleshy, white. 

 Stems many, either erect, or 

 more or less procumbent, 

 round, hairy, green or red. 

 Leaves scattered, sessile, en- 

 tire or undulated, oblong or 

 lanceolate, sometimes nearly 

 linear, very hairy, dark-green 

 above, paler beneath. The 

 flowers are in terminal, rarely 

 lateral, corymbose umbels, 

 with an involucre of nume- 

 rous, linear, subulate bracts. 

 The calyx is small, 5-parted, 

 reflexed. The corolla is of 

 a bright orange colour, 5- 

 parted, reflexed, The sta- 

 mineal croWn has five erect, 

 cucullate segments or leaves, 

 with an incurved appendage 

 or horn at the base of each. 

 The follicles are two, often 

 one or both abortive, long, 

 narrow, and acuminated. 

 The seeds are furnished with 

 a long silky appendage. 



This species is found 

 in most parts of the 

 United States, but is most 

 abundant to the South, 

 growing in open situa- 

 tions, in gravelly and 

 sandy soils. It flowers 



