Pollen morphology and varition of the genus Fortunearia (Hamamelidaceae) endemic to China

Abstract

This paper examines the detailed pollen morphology of Fortunearia Rehd. & Wils.(Hamamelidaceae), a monotypic genus endemic to China, by light microscope, scanning electron microscope, and transmission electron microscope. Our datacorroborate earlier reports: Fortunearia pollen is mostly tricolpate, rarely nontypical pantocolpate or pantoporate, pores irregular in outline, unequal in size, veryindistinctly delimited; colpus membrane tuberculate, exine sculpture reticulate,consisting of semi-tectate, columellate layer, foot layer, and endexine. Pollen morphology variation is rather large. It correlates with the variability of gross morphology in this genus. The present study supports the placement of Fortunearia, as wellas Sinowisolia, in the tribe Eustigmateae, rather than in the Corylopsideae orDistylieae, as suggested by other botanists.