Noun | 1. | family Characeae - green algae superficially resembling horsetail ferns: stoneworts protoctist family - any of the families of Protoctista Charales, order Charales - small order of macroscopic fresh and brackish water algae with a distinct axis: stoneworts stonewort - any of various submerged aquatic algae of the genus Chara having nodes with whorled filamentlike branches; usually encrusted with calcium carbonate deposits Chara, genus Chara - green algae common in freshwater lakes of limestone districts genus Nitella, Nitella - fragile branching stoneworts |