Pollen Morphology of the Genera Panurea and Bowdichia (Leguminosae: Papilionoideae: Sophoreae)

Abstract

Bowdichia and Panurea are the only genera in the tribe Sophoreae with psilate pollen. The pollen of the four species recognised in the two genera can be divided into three distinct types: (1) Spheroidal in shape, tricolporate with long colpi (Bowdichia); (2) Oblate in shape with three very short colpi or pori (Panurea bowdichioides); (3) Cuboid in shape, tetracolpate (Panurea longifolia). The exine stratification of Bowdichia is very distinctive with a thick tectum, short columellae and thick foot layer. The two species of Panurea have a similar exine stratification with long columellae and much thinner tectum and foot layer. Exine stratification provides additional evidence to support the generic relationships of P. bowdichioides, a new species, which has some floral characters similar to Bowdichia and simple leaves of Panurea. Pollen morphology provides additional evidence to support the view that Bowdichia and Panurea have no very close relatives in the Sophoreae.