NEPENTHACE^: DATISCACE^I. 491 



regions of South America, and growing also in the temperate and 

 cold regions of Europe, Asia, and America. There are 8 known genera, 

 and 130 species. Examples Asarum, Aristolochia. 



1010. The plants of the order are generally bitter, tonic, and stimu- 

 lant. Some are acrid, and act as emetics. The leaves of Asarum europceum 

 are used as an acrid emetic under the name of Asarabacca. The roots 

 appear to have greater activity than the leaves. The powdered root 

 and leaves enter into the composition of cephalic snuffs, which cause 

 sneezing by their irritation, and are used in cases of headache and 

 ophthalmia. An active crystalline substance, called Asarin, exists in 

 the plant. Asarum canadense, Wild Ginger, or Canada Snake-root, is 

 used as a spice in Canada. The shrubby species of Aristolochia have 

 a peculiar arrangement of vascular bundles in their wood. There are 

 no concentric zones, but a number of separable wedges (^[ 90). The 

 name of Birthwort, given to Aristolochias, depends on their supposed 

 action on the uterus. Some of them are used as emmenagogues. The 

 root of Aristolochia serpentaria, Virginian Snake-root, is a stimulant 

 tonic. The plant is a native of the United States. It was formerly 

 used as an antidote to snake-poison. It is now employed occasionally 

 as a tonic diaphoretic. Aristolochia longa, rotunda, and Clematitis, were 

 celebrated in ancient times as uterine remedies. The roots of many of 

 the species have a strong aromatic taste. Those of Aristolochia anyui- 

 cida are said to stupify snakes. 



1011. Order 162. Nepenthacete, the Pitcher-plant Family. (Apet. 

 Diclin.) Flowers dioecious. Perianth 4-parted, inferior ; aestivation 

 imbricated. Male flowers : Stamens united in a solid central column ; 

 anthers about 16, forming a spherical head, extrorse, and with 

 longitudinal dehiscence. Female flowers : Ovary free, four-cornered, 

 4-celled ; ovules 00 ; stigma sessile. Fruit a 4-celled. 4-valved 

 capsule, with loculicidal dehiscence. Seeds 00, ascending, very 

 minute, fusiform, with a loose testa ; nucleus less than the seed, sus- 

 pended by the chalaza ; embryo in the midst of fleshy albumen ; 

 cotyledons plano-convex ; radicle pointing to the hilum. Herbs, or 

 half-shrubby plants, with alternate leaves, slightly sheathing at the 

 base, having a foliaceous petiole, which forms an ascidium at its ex- 

 tremity, and the lamina in the form of a lid (fig. 184). Natives of 

 swampy ground in the East Indies and China. They have no known 

 properties. The pitchers have been found to contain a solution of 

 binoxalate of potash. Some chemists have detected muriate of soda, 

 malic, and other acids in them. Spiral vessels abound in all parts of 

 the pitcher plants ; and the woody bundles are without concentric 

 zones. Lindley gives 1 genus, and 6 species. Example Nepenthes. 



1012. Order 163. Datiscacete, the Datisca Family. (Apet. 

 Diclin.) Flowers unisexual. Male Flowers: Perianth 3-4-divided. 

 Stamens 3-7; anthers linear, membranous, dithecal, with longitu- 



