Trichome and Pollen Morphology of Barbeya (Barbeyaceae) and Its Relationships

Summary Vestiture of Barbeya is composed of various‐sized, curly, unicellular, non‐glandular trichomes. Attenuate, unicellular (micropapillate), non‐glandular and capitate glandular trichomes common to all Urticales are absent. Pollen of Barbeya, unlike those of Urticales, is tricolporate, but like those of some more Hamamelididae, has a stratified wall structure containing a thin, granular layer. Evidence from trichome and pollen morphology, as well as from other sources, favors a transfer of Barbeya from Urticales into its own order Barbeyales. Barbeya may be an independent offshoot from a common ancestor of Casuarinales, Fagales, Juglandales, Myricales, and Urticales.