WATER PLANTAIN FAMILY. Alismaceae. 



WATER PLANTAIN FAMILY. Alismacece. 



Marsh herbs with long-stemmed leaves, and flowers of 

 three orders, thus : 



1. With stamens and pistil, 2. Staminate and pistil- 

 late growing on one plant, 3. Staminate and pistillate 

 growing on different plants. The flowers have three 

 conspicuous petals and generally six stamens ; they are 

 visited by numerous insects which undoubtedly assist in 

 the process of fertilization. 



The leaves, all from the root, are olive 

 Water Plantain , 



Alisma Plan- S reen > strongly veined, and elliptical but 

 tago-aquatica very variable in shape, broader or longer, 

 White or pale and sometimes heart-shaped at the base. 

 pink The flower-stem is tall and symmetrically 



b " r y ~" branched, displaying the three-petaled, 



very small white or rarely delicate pink 

 flowers to great advantage. The flowers are perfect, 

 with six stamens and a pistil ; they are possibly self-fer- 

 tilized, but more probably cross-fertilized by the beelike 

 drone-flies (Syrphidce), all pollen-eaters and honey- 

 drinkers. The plant is 1-3 feet high, and is found in the 

 shallow water of ponds and sluggish streams every- 

 where. See Appendix. 



The genus Sagittaria, always white- 

 Sagittaria flowered, is remarkable for its manifold 



latifolia phases which have recently been resolved 



White into twelve distinct species, and four forms 



July-Septem- an( j Qne var j e ty o f tne S p ec ies latifolia. 



The leaves are deep lustrous green and 

 distinctly arrow-shaped ; hence the name derived from 

 the Latin sagitta, an arrow. The four forms of S. lati- 

 folia as defined by Dr. Robinson are: Forma obtusa 

 (Muhlenberg) with very broad obtuse leaves. Forma 

 hastata (Pursh) leaf -blades and their lateral bases oblong 

 lance-shaped, and acute. Forma gracilis (Pursh) leaf- 

 blades and their lateral bases narrowly linear. Forma 

 diversifolia (Engelmann) leaf-blades partly sagittate and 

 p irtly lance-shaped or elliptical without basal lobes. 

 J. (>. Smith considers these forms as follows : Form a, 

 flowers mostly of the third order above described, and 

 6 



