,KDER LXXXVm. APOCYNACEJE. ORDER LXXXIX. ASCLEPIADACEJE. 



121 



united at base. Corolla convolute, sometimes induplicate in pre- 

 floration, 4 12-parted, regular. Stamens as many as the seg- 

 ments of the corolla, inserted on the tube, alternately with them. 

 Ovary 1-celled, free, sometimes apparently 2-celled, on account 

 of the 2 introflexed placentae. Style 1, or wanting. Stigmas 

 usually 2, sometimes 1. 



as many, which are united in pairs by a connecting thread, and 

 are attached to the glands of the stigma, from which they soon 

 hang loose, being released from their cells. Ovaries 2. Styles 2, 

 often very short. Stigmas united into 1 column for both ovaries. 

 Fruit consisting of 2 follicles, 1 sometimes abortive. Seeds usually 

 with a coma. 



Fig. 29. 



An order of beautiful plants generally pervaded by an intensely bitter 

 tonic principle. Gentians (Gentian), flg. 29, and Menyanthes (Buok- 

 beari), are examples. 



GROUP vm. 



ORDER LXXXVIII. Apocynacese. 



Trees, shrubs, or herbs, with a milky juice. Leaves opposite, 

 or verticillate, rarely alternate, without stipules. Flowers regu- 

 lar. Sepals 5, united, persistent Corolla 5-lobed, twisted in 

 prefloration. Stamens 6, alternate with the segments of the 

 corolla. Filaments distinct. Anthers 2-celled, sometimes slightly 

 connected. Ovaries 2, distinct, rarely united, but with 2 united 

 styles or stigmas. Fruit usually a pair of follicles, 1 sometimes 

 abortive. Seeds often with a coma, or tuft of hairs. 



A chiefly tropical order, distinguished by the active, usually poisonous pro- 

 perties of the juice, which usually contains more or less strychnine, which is 

 generally obtained from an East Indian species of Strychnos. Some of the 

 s that yield the Upas belong to this genus, as also that which furnishes the 

 dreaded Woorari poison of Guiana. The juice, also, yields caoutchouc, which 

 in Sumatra, is obtained from the Urceola clastica. Apocynum (Dog-lane, 

 Indian Hemp), and Nerium (Oleander), are examples. 



ORDER LXXXIX. Asclepiadacese. 



Herbs, or shrubs, usually with a milky juice. Leaves usually 

 opposite, sometimes alternate or verticillate. Flowers generally 

 in umbels, sometimes in racemes or corymbs. Sepals 5, slightly 

 united at base. Corolla regular, consisting of 5 nearly distinct 

 petals. Stamens 5, inserted at the base of the corolla, alternate 

 with its segments united by their filaments into a tube. Anthers 

 2-celled. Pollen cohering in masses as many as the cells, or twice 

 16 



Fig. 80. 



A large and chiefly tropical order, with properties much like the last, but 

 less active. The various species of Asclopias, two of which are seen in figs. 30 

 and 81, are our principal Northern representatives. 



Fig. 81 



