Figure 1.

Multicellularity and morphological complexity in the green lineage. Simplified cladogram based on data in Leliaert et al. (2012) and De Clerck et al. (2012) showing relationships among the green lineage (chlorophytes and streptophytes) and their sister groups, red algae and glaucophytes, which together comprise the Archaeplastida. The major classes in the green lineage are in bold and, in some cases, further expanded into subgroups. Note that the prasinophytes are a paraphyletic grouping of the most primitive chlorophyte algae. The streptophytes are divided into the charophyte algae (a paraphyletic grade) and the embryophytes (land plants). To the right are depicted the most complex type of cellular/multicellular organization in each clade and whether cell type differentiation occurs in multicellular forms. NA, not applicable for giant unicellular forms.