A GUIDE TO THE WILD FLOWERS 303 



•3W 



Often growing in large floating mats. Nova Scotia to New 

 Jersey, and westward. Fig. 927. There are several other 

 species, and some forms in another closely related genus 

 have several instead of one thread-like root. 



928. Mermaid-weed. Proscrpinaca palustris. {Haloragid- 

 accae.) An aquatic with obvious stem rooted in mud or sand, 

 and two sorts of leaves. The submerged ones ere much 

 divided into thread-like segments which have minute teeth 

 and nearly always a black prickle at the stem-joint. Above 

 surface leaves either floating or free in the air, 1-23/2 in. long, 

 oblong, and with sharp, rather numerous teeth. Flowers 

 minute, without petals, and borne at the joints of the above- 

 surface leaves. In water or along water sides. New Brunswick 

 to Florida, and westward. Fig. 928. 



929. Carolina Water-shield. Cabomba caroliniana. (Ca- 

 bombaceae.) A slender gelatine-coated aquatic with most of 

 its leaves submerged, and much divided into thread-like 

 segments, but with a few floating leaves. These are oblong 

 or oval-oblong, ^-i in. long, toothless, and long stalked. 

 Flowers on long stalks, floating on the surface, whitish- 

 yellow, scarcely 3^ in. wide. In ponds or in sluggish streams. 

 Missouri and Illinois, southward and eastward to No. Caro- 

 lina and Texas. Fig. 929. 



930. Common Pondweed. Potamogeton natans. (Zanni- 

 chclliaceac.) A rather common aquatic with two sorts of 

 leaves, the submerged ones long and thread-like, the floating, 



