ALISMACEiE. 189 



Sagittaria. L. 19. 12. 



So called from the arrow-shaped leaves of many species. In 

 this country the plants are not employed for any useful purpose. 

 In China, one species is " cultivated for food." Lind. About 

 a dozen species have been described, most of which are found in 

 this country, and 4 are pretty common in this State. Leaves 

 nearly radical, stand erect, and nearly equal to the length of the 

 scape or naked culm. Aquatics. 



Floral envelopes 6-parted, 3 outer, calyx-like, and persistent ; 

 3 inner, colored, petal-like ; stamens and pistils in separate flow- 

 ers ; capsules compressed, 1-seeded. 



8. sagittifolia. L. Arrow-head. Stem or scape often 2 

 feet high, with the lobes of the sagittate leaves long, straight, 

 acute, lanceolate ; flowers white, whorled in threes ; July. Com- 

 mon also in Europe. 



The leaves are very variable ; sometimes so wide as to give the 

 name broad-leafed to the variety ; sometimes with rather hastate 

 leaves, for another variety ; sometimes very slender-leafed, form- 

 ing a slender and delicate variety ; and one variety has leaves so 

 obtuse, as to be often called S. obtusa, as a distinct species, though 

 the change from the narrow and acute leaves can be often traced 

 to the broad and obtuse within the distance of a few rods where 

 the plants abound. 



&. heterophylla. Ph. A more slender plant, with leaves linear 

 and lanceolate, or sagittate and narrow-lobed ; few-flowered ; 

 ditches and ponds ; July. A foot or more high. 



S. acutifolia. Ph. Acute-leafed Arrow-head. Stem or 

 scape 6 inches high, with subulate, acute leaves, convex on the 

 back, and sheathing at the base ; few-flowered ; flowers on pedi- 

 cles ; muddy places ; July. 



It is probable that some other species, as they are commonly 

 considered, are confounded with the preceding. 



