848 WEEDS AND USEFUL PLANTS. 
staminate ones phone. Calyx green and persistent. Petals white, decid- 
uous, imbricated i the bud. Stamens numerous ; anthers extrorse. 
pare re fi in Saprenaed- globose heads, in fruit becoming flattened 
—_— aken Pilar oothish perennials ; roots often tuberiferous ; eaves 
polym sephioas: vissally sagittate ; scape ‘sheathed at the base by the bases 
of the long cellular peti ioles 
243 
varia’bilis, Engelmann. Scape simple or branched ; leaves 
wey a Serine, Lipton: sagittate ; pedicels of the fertile faces about half 
the ‘sterile ones; filaments awl-shaped, nearly twice the 
Fic. 243. The Arrowhead (Sagittaria variabilis). © 6 > | 
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