AQUATIC PLANTS OF FRESHWATER 



SAGITTARIA 



A small genus of very variable plants of which the number of species 

 differs with different authorities, and, though there are quite lOO specific 

 names, Micheli has reduced them to 13 species, 4 of which are doubtful. 

 They are widely distributed in temperate and torrid regions, and in shallow 

 water are effective foliage plants, most of which have the arrowshaped- 

 leaves from which the name is derived, with small buttercuplike flowers in 

 successive whorls on an erect 

 scape. They are perennials of 

 easy culture, many propagating 

 both by runners and seeds, grow 

 on the muddy bottoms of shallow 

 streams, ponds and lakes, raising 

 their leaves above the water. In 

 the beds of rapid streams, when 

 exposed to a vigorous current, 

 the leaf blades are almost entirely 

 changed to the form of a spade, 

 and not infrequently all traces of 

 lamina are absent and the leaf is 

 lengthened to form a limp, flat, 

 pale-green ribbon much resem- 

 bling Vallisneria. This is 

 characteristic oiS.natans, S.pusilla 

 and S. sinensis or S. gigantea, 

 which are grown in aquaria and 

 sucessfully in shaded ponds in 

 summer. 



Sagittaria nutans (Mul.) or 

 Floating or Ribbon Arrowhead, 

 Fig. I I a, is a variety of S. 

 fusilla and is the best of all 

 aquarium plants, generally to be 

 had of dealers in aquatics, who 

 propagate it in tanks and aquaria. 

 It originates in a tuft on the 

 bottom of the water and spreads 

 by runners usually in the direc- 

 tion of the strongest light. The Fig. 112 

 clear-green linear leaves are Floating Arrowhead, 



„J ..U " ..• I ..L J Sagiitaria Baraw, with rhizoid, blossom, fruit, deuils of leaf 



nerved their entire length and and a floral leaf. Reduced o;e-thi;d. 



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