SPERMATOPHYTA— ALISMACEAE 



335 



ALISMACEAE. D. C. Water-Plantain Family- 

 Aquatic or marsh herbs, generally with smooth, sheathing leaves ; flowers 

 perfect, monoecious or dioecious ; sepals 3, persistent ; petals 3, the larger, 

 deciduous, imbricated in the bud; stamens 6 or more; anthers 2-celled, extrorse; 



Fig. 135. Water Plantain (Alisma Plantago). A common marsh plant. 



pistils numerous or few, usually with a single ovule in each cell ; fruit an 

 achene ; seeds small, erect. About 70 species of wide distribution in swamps. 

 The Water Plantain (Alisma Plantago) of Europe and North America is com- 

 mon in the northern states. Several species of Arrowheads (Sagittaria) are 

 used as food by the Indians and Chinese. 



Sagittaria L. Arrowhead 



Perennial with tuber-bearing root stocks and milky juice; basal leaves long- 

 petioled, scape sheathed at the base; flowers monoecious or dioecious, borne 

 near the ground in whorls ; sepals persistent in pistillate flowers, reflexed or 

 spreading; petals 3, white, deciduous; stamens indefinite; pistillate flowers with 

 distinct ovaries; ovule solitary; fruit an achene in dense clusters; seed erect, 

 curved. 



Sagittaria Engelmanniana, J. G. Sm. 



Perennial with stoloniferous roots; leaves very variable; scape 1-4 feet 

 high, angled; lower whorl fertile; pedicel of fertile flowers, at least half the 

 length of the sterile one ; filaments smooth ; achenes obovate with a long 

 curved or horizontal beak. 



Distribution. ' Across the continent and in Europe. 



Poisonous properties. The tuberous stolons are eaten; if there is any 

 poison contained in the raw state it is probably removed by methods of prepara- 

 tion for food. 



