pollen morphology of the subtribe Oncospermatinae (Palmae: Arecoideae: Areceae)

The pollen morphology of eight genera and 11 species of the subtribe Oncospermatinae has been studied. In general the pollen is monosulcate, elliptical in polar view and small to medium in size. There is considerable variation in exine thickness, in ornamentation and in stratification. Deckenia has intectate clavate pollen, all the other genera have tectate pollen grains. The pollen of Acanthophoenix is reticulate with a thick tectum and foot layer while that of Oncosperma has thin tectum and clavate supratectal ornamentation. Tectiphiala has pollen with a perforate or scrobiculate tectum but with variation. The exine of Verschaffeltia and Roscheria is thin, the tectum perforate but smooth in the former and transversely ridged in the latter. Phoenicophorium is very distinct with echinate pollen with smooth supratectal spines and Nephrosperma has a thick exine, finely perforated tectum and thin foot layer. This wide range of variation in pollen morphology reflects the considerable morphological variability within the subtribe and throws little light on relationships between genera within the subtribe.