Seed morphology of zanthoxylum (Rutaceae) in China and its systematic significance

Seed morphology of 31 species belonging to the genus zanthoxylum in china were examined using light microscopy and scanning electron microscopy. the macro- and micro-morphological characters of seed,including seed surface,colour,shape,size and coat sculpture were examined. under light microscopy,the results indicate that seed surface is more or less smooth; seed colour is black or brown to red; seed shape is spheroidal or elliptical and size is large. under scanning electron microscopy,the seed epidermal cellular arrangement is netted and the epidermal cell shape ranges from tetragonal to hexagonal in all taxa. the fine relief of the outer cell wall is rough,smooth and finely folded sculpturing. the systematic significance of these seed characters was evaluated. it was proved that the seed coat sculpture was a valuable character which offers evidence to solve some taxonomical problems of zanthoxylum. based on the seed morphological data,the present study proved that subgen. fagara and subgen. zanthoxylum shared many common seed characters,suggesting a close relationship between the two subgenera. the value of some characters of seed in identifying species of zanthoxylum is also discussed here. © 2016,pakistan botanical society. all rights reserved.