† Background and Aims: Long-lived underground populations of mycoheterotrophic gametophytes and attached sporophytes at various developmental stages occur in lycophytes. Young underground sporophytes obtain carbon solely from the gametophyte and establish nutritional independence only after reaching the soil surface, which may take several years. This prolonged period of matrotrophy exceeds …
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…