Review of Vegetative Branching in the Palms (Arecaceae).

Vegetative branching is common in the palms (Arecaceae). However, current terms to describe vegetative branching diversity are not consistent and do not cover the full range of branching types. In this study vegetative branching types in the palms were reviewed and defined, and the phylogenetic distribution of palm branching types was described. Branching types were described from a literature review and field observations; 1903 species representing all 181 genera were included. Five branching types were found: lateral axillary branching, shoot apical division, false vivipary, abaxial branching, and leaf-opposed branching. Most species (55%) exhibited no vegetative branching. Lateral axillary was the most common branching type. Lateral axillary branching and shoot apical division were predicted to be the earliest-evolved branching types. The present study suggests that branching types have different evolutionary histories, and it is likely that the solitary habit is more common now than when palms initially diverged from commelinid relatives. [ABSTRACT FROM AUTHOR]