Pegged and smooth rhizoids in complex thalloid liverworts (Marchantiopsida): …

Rhizoids played essential roles in the early evolution of land plants. All liverworts, the closest living relatives of the first land plants, produce unicellular rhizoids, except for Haplomitrium. The complex thalloids are uniquely characterized by dimorphic rhizoids: smooth rhizoids like those also produced by the simple thalloid and leafy clades and pegged rhizoids. Although this dimorphism h…