126 PATAGONIAN EXPEDITIONS I BOTANY. 



(Incertce Sedis.) 



Family CHARACE^E. STONEWORTS. 



Aquatic cellular plants with segmented stems, the internode having 

 one long axial cell, and the node consisting of several short cells. 

 Whorled leaves, sometimes with axillary branches, arise from the node, 

 and are themselves segmented and leaf-bearing ; also bearing sexual re- 

 productive organs at their nodes. Antheridia globular, bearing in their 

 interior bundles of jointed filaments which produce many coiled and 

 ciliated spermatozoids. Oogonia ovoid, consisting of 5 filaments spirally 

 wound around a single egg-cell, and surmounted by crown-cells. 



Species 160, in fresh or brackish water. 



CHARA Linn. 



Stem and leaves usually corticated by longitudinal cells, often becom- 

 ing encrusted with lime. Spore-sac above antheridium. Crown-cells 5, 



C. FCETIDA A. Braun (C. mdgaris Linn. p. p.). 



Cortical tubules twice as many as the leaves. Whorls about 8-leaved ; 

 stipular circle double, weak. 



South Patagonia : by J. B. Hatcher, near Rio de la Santa Cruz. De- 

 termined by the late T. F. Allen. 



(Nearly cosmopolitan: as is C. fragilis Desv. the other section of C. 

 vulgaris L., distinguished by its cortical tubules thrice as many as the 

 leaves. Both are much encrusted and fragile.) 



