Conspecificity of Some Charophytes1

Sweets Lake, British Columbia, is the type locality for plants originally described as Chara buckellii. Plants from this locality liave been crossed successfully to a second clone from Laguna La Drava, Argentina, the type locality for Nitellopsis bulbillifern. Plants from both clones were also crossed with others from Texas, New Mexico, and Wyoming that agree in most respects with. Robinson's original description of C. longifolia. On the basis of such crosses we suggest that all 3 taxa are biologically conspecific. There is no evidence, either from the field or experimental crosses, of gene flow between C. longifolia and C. hornemannii; the two should be considered separate species.