Caryopsis micromorphological survey of the genus Themeda (Poaceae) and allied spathaceous genera in the Andropogoneae

Authors: YU ZHANG, XIAOYING HU, YUNXIAO LIU, QING LIU

Abstract: A caryopsis micromorphological survey of 15 species of the genus Themeda Forssk. (Poaceae) and 4 species of allied spathaceous genera in tribe Andropogoneae allowed the recognition of 2 types of caryopses based on the ventral face and embryo shape for the first time. One kind of caryopsis had a concave ventral face with a grooved embryo, and the other kind of caryopsis had a flat ventral face with a keel-shaped embryo. Although the ventral face and embryo shapes had limited taxonomic value at the infrageneric level, the caryopsis shapes, embryo proportion, and sculpturing patterns were found to be valuable taxonomic characters at the interspecific level in Themeda. Consistent micromorphological characters of style base persistence and dorsiventral compression were observed for the first time in the caryopses of representative species of spathaceous genera in the Andropogoneae.

Keywords: Micromorphology, spathaceous genera, taxonomy

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