Streptophyta (/strɛpˈtɒfɪtə,ˈstrɛptoʊfaɪtə/), informally thestreptophytes (/ˈstrɛptəfaɪts/, from theGreekstrepto 'twisted', for the morphology of the sperm of some members), is aclade ofplants. The composition of the clade varies considerably between authors, but the definition employed here includes land plants and all green algae except theChlorophyta and the more basalPrasinodermophyta.[4]
The composition of Streptophyta and similar groups (Streptophytina,Charophyta) varies in each classification.[5][citation needed] Some authors include only the Charales and Embryophyta (e.g., Streptophyta,[1][6] Streptophytina[3]); others include more groups (e.g., Charophyta,[3][6] Streptophyta,[7][8] Streptobionta[9]); some authors use this broader definition, but exclude the Embryophyta (e.g., Charophyta,[10][8] Charophyceae[citation needed], Streptophycophytes[citation needed]).
The clade Streptophyta includes both unicellular and multicellular organisms. Streptophyta contains the freshwater charophyte green algae and all land plants that reproduce sexually by conjugation.Mesostigma viride, a unicellular green flagellate alga may be a basal Streptophyte.[11][12]
^Cavalier-Smith, T. (1993). "The origin, losses and gains of chloroplasts.".Origins of plastids. Springer US. pp. 291–348.
^Liang, Z; Geng, Y; Ji, C; Du, H; Wong, CE; Zhang, Q; Yu, H (2020). "Mesostigma viride genome and transcriptome provide insights into the origin and evolution of Streptophyta".Advanced Science.7 (1).doi:10.1002/advs.2019018501901850 (inactive 12 July 2025).{{cite journal}}: CS1 maint: DOI inactive as of July 2025 (link)
^Nedelcu, AM; Borza, T; Lee, RW (2006). "A land plant–specific multigene family in the unicellularMesostigma argues for its close relationship to Streptophyta".Molecular Biology and Evolution.23 (5):1011–1015.doi:10.1093/molbev/msj108.PMID16476689.
