348 Class XXI. Order VIII. 



far more powerful, so much so, as to leave a permanent soreness 

 of many hours' continuance. This acrimony is of a volatile na- 

 ture and disappears upon boiling or drying. It consists of an in- 

 flammable substance, volatile at low temperatures, and not com- 

 bining with water, or alcohol. May. Perennial. 



408. CALLA. 



CALLA PALUSTRIS. L. Northern Calla. 



Leaves heart shaped ; spathe flat ; spadix covered 

 with perfect flowers. 



A handsome aquatic plant. Root as large as the finger, joint- 

 ed, creeping. Leaves on long stalks, smooth, entire, heart 

 shaped, acuminate with an involute point. Scape smooth, a 

 little compressed. Spathe oval, spreading, recurved, clasping at 

 base, ending in a cylindrical or involute point ; green on the 

 outside, white within. Spadix oblong-oval, covered with flow- 

 ers which present the appearance of large, crowded, greenish 

 germs, surrounded with white stamens. 



The root is acrid like that of Arum, but the pungency disap- 

 pears in drying. Linnaeus says the Laplanders use it for bread. 



CALLA VIRGINICA. Mich. Virginian Calla. 



Leaves sagittate-hastate, with obtuse lobes ; spathe 

 elongated, incurved. Mich. 



Syn. J!RUM VIKGINICUM. L. 



The leaves of this plant may be mistaken at sight for those of 

 Sagittaria, from which they differ in their shorter and more ob- 

 tuse lobes, and the different distribution of their nerves. They 

 are radical, numerous, large and smooth, with semicylindrical 

 petioles. Spathe erect, green, fleshy, cylindrical, acuminate, and 

 waved at its edge. Spadix shorter than the spathe, tapering to 

 a point, and covered with flowers. Anthers oblong-hexagonal, 

 covering the upper part of the spadix. Germs below, roundish, 

 tipt with the stigma. Borders of ponds. June, Julj'. 



409. FAGUS. 



FACUS FERRUGINEA. Jlit. , Beech Tree. 



Leaves ovate, acuminate, downy underneath, with 

 large teeth, ciliate at the margin. Willd. 



