Wild Flowers East of the Rockies 23 



WATER PLANTAIN FAMILY (Alismaceae.) 



GENUS ARROW-HEAD (Sagittaria,) Arrow-heads 

 or Sagittarias are among our most beautiful water 

 plants. The leaves vary greatly in shape but are 

 always graceful in appearance. All species have 

 three pure white petals with a golden center formed 

 by the large anthers. The following are the most 

 distinctive of the twelve species now recognized in 

 Gray's Botany. They usually grow in the water but 

 sometimes on the muddy shores, and flower in June 

 or July. Except as noted, these species are common 

 in the U. S. and southern Canada. 



BROAD-LEAVED ARROW-HEAD (Sagittaria latifo- 

 lia) has broad arrow-shaped leaves on long petioles 

 from the root. The 3-petalled white flowers grow 

 in whorls of three, the upper ones being staminate 

 and the lower pistillate. Seed, winged on both edges 

 and with a twisted horizontal beak. This species is 

 smooth but a variety, ( pubescens) has the stem 

 quite wooly. Common in the whole of our range. 



NARROW-LEAVED ARROW-HEAD (S. Engelman- 

 niana) has very narrow leaves with linear sagittate 

 bases. The seeds are winged but the beak points 

 upwards instead of being bent at an angle as in the 

 last. 



LANCE-LEAVED SAGITTARIA (S. heterophylla) 

 has lance-shaped leaves with usually no sagittate ap- 

 pendages to the bases. The seed is round, winged and 

 with a vertical beak. This species is found from 

 Me. to Minn, and southwards. 



GRASS-LEAVED SAGITTARIA (S. gracillima) has 

 linear, grass-like leaves and grows wholly under 

 water. In July a long slender flowering stem reaches 

 to the surface and floats the small, 3-petalled white 

 flowers. Found locally in the East. Used extensive- 

 ly in aquaria as it is an excellent oxygen giver. 



