576 



AEISTOLOCHIACE.'E. 



The plants of the order are generally bitter, tonic, and stimulant. 

 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 



Mg. 813, 



Fig. 816. 



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 



Figs. 808-816.— Organs of fructiticatlon of Aristolochia Clematitis, to illustrate the natu- 

 ral order Aristolochiacese. Fig. 808. Flower entire, consisting of an inferior ovary, and a 

 superior, irregular, funnel-shaped perianth, o. Part of the perianth adherent to the ovary. 

 t, Pai-t of the tube of the perianth, with a swollen portion at the base, enclosing the anthers 

 and stigma. I, Limb of the perianth prolonged laterally in a tongue-like form. Fig. 

 809. Diagram of the flower, showing three divisions of the perianth, six anthers, and six 

 cells of the ovary. Fig. 810. Lower part of the flower cut vertically, o, Ovary with 

 numerous ovules, s. Radiating stigma, a. Anthers, c, Swollen part of the tube of the 

 perianth. Fig. 811. s, Stigma with the anthers adhering to the column in pairs, o. Sum- 

 mit of the ovai-y. c. Swollen part of the tube of the perianth. Fig. 812. Horizontal sec- 

 tion of the six-celled ovary. Fig. 813. Ripe fmit. Fig. 814. Angular seed. Fig. S16. 

 Seed cut vertically. (, Integument thickened near the chalaza. p, Fleshy perisperm. e, 

 Minute embiyo. Fig. 816. Embrj-o separated, with cotyledons and radicle. 



