WEBSTER, GRADY L.* and KEVIN J. CARPENTER. Herbarium, Sect. of Plant Biology, University of California, Davis CA 95616. - Pollen morphology and phylogeny in Euphorbiaceae, subtribe Flueggeinae.
The affinities and delimitation of four closely related genera of
Euphorbiaceae subtribe Flueggeinae-- Breynia,
Glochidion, Phyllanthus, and Sauropus-- are
examined by SEM observations (supplemented by LM) on pollen of 35
species, mostly belonging to the primarily paleotropical subgenera of
Phyllanthus: Emblica, Eriococcus, and
Phyllanthodendron. The plesiomorphic condition in this clade
within subtribe Flueggeinae appears to be that found in subgenus
Emblica: prolate, 4-colporate grains with reticulate exine;
pollen grains in subgenus Phyllanthodendron are 5-6-colporate,
in subgenus Eriococcus pantoporate. The pollen grains of
Breynia, Glochidion, and Sauropus appear most
similar to Phyllanthus subgenus Phyllanthodendron. The
palynological data are useful in providing insights into phylogeny
within subtribe Flueggeinae, but are not decisive in resolving
problems of generic delimitation.
Key words: Euphorbiaceae, phylogeny, pollen morphology, subtribe Flueggeinae