Pollen morphology of the Chloridoideae (Gramineae)

A Contribution to the Pollen Morphology of Family Gramineae

Pollen morphology of 20 species belonging to the 14 genera of the family Gramineae has been investigated using light microscope and scanning microscope. It is a stenopalynous in nature. Pollen grains mostly spheroidal, monoporate rarely diporate, ±circular, pores small operculate, non-operculate, annulate or non-annulate. Tectum areolate to scabrate. On the basis of exine ornamentations 5 disti...

Glume absence in the Orcuttieae (Gramineae: Chloridoideae) and a hypothisis of intratribal relationships

This study addresses glume absence in tribe Orcuttieae. In Orcuttia califomica, 0. inaequalis, and 0. viscida, all spikelets possess two glumes except for the terminal spikelet of the inflorescence, which lacks both glumes. In 0. pilosa and Tuctoria greenei the terminal spikelet lacks only the first (proximal) glume, whereas in 0. tenuis, T. fragilis, and T. mucronata both glumes are developed ...

Pollen Morphology of the Fouquieriaceae

Pollen Morphology of Rapateaceae

Evolution of pollen morphology.

Over evolutionary time, the morphology of angiosperm pollen has evolved toward an increasing number of apertures, among other things. From a neo-Darwinian point of view, this means that (i) some polymorphism for aperture number must exist and (ii) there must be some fitness increase associated with increasing the aperture number. Pollen types with different aperture numbers often occur in the s...