282 FEENS : BEITISH AND FOBEIGN. 



162. PILtTLARIA, Linn. 



Plants with filiform leaves, from a creeping rhizome under 

 ■water. Sporangia (conceptacles) radical (at the base of the leaves 

 on the rhizome), globose, coriaceous, 2-4-celled, 2-4-valved, each 



Genus 162. — Plant, natural size. No. 1. 



cell containing different kinds of bodies : — 1. (Antheridangia), 

 consisting of vesicles containing many minute granular spores; 

 2. (Ooplwridangia), each containing a single large spore. 



1. P. globulifera, Linn.; WilU. Sp. PI. 5, p. 535; Bolt. 

 Fil. t. 40 ; Sclik. Crypt, t. 173 ; Eng. Bot. i. 521. — 

 Europe and Britain. 



163. ISOETES, Linn. 



Plants with awl-shaped leaves, from a thick creeping rhizome 

 wider water or out of water. Sporangia (conceptacles) borne in the 



