AN ENUMERATION OF CULTIVATED TEENS. 



283 



axis of the leaves at their base, globose, 1 -celled, traversed by 

 thread-like receptacles of two kinds : 1. (Antheridangia), 

 containing numerous small spores; 2. (Oophoridangia), con- 

 atining large 4-sided spores. 



Genus 163. Plant, natural size. No. 1. 



1. I. lacustris, Linn.; Willd. Sp. PI. 5, p. 534; Bolt. Fit. 

 tAl ; Sclilc. Crypt. 1. 173 ; Eng. Sot. 1084. Europe, 

 Britain. 



