Pollen and translators were obtained from flowers rehydrated
in 3% phosphate-buffered glutaraldehyde. For light microscopy
the pollen was acetolysed according to the method of Erdtman
(1960), mounted in glycerine jelly and sealed with paraffin wax.
A minimum of 15 pollen tetrads were examined for every
specimen. Measurements were made with a light microscope.
For scanning electron microscopy (SEM), pollen was acetolysed,
air-dried on stubs, coated with gold and examined with a
Jeol Winsem 6400 microscope at 5 kV (Centre for Microscopy,
University of the Free State). The translators were mounted on
stubs with double-sided tape, coated with gold and examined
with the same microscope. The colleters were examined by
removing the sepals from the glutaraldehyde fixed flowers,
dehydrated in an alcohol series, critical point dried, mounted on
stubs, coated with gold and examined with a Jeol Winsem 6400
microscope at 5 kV. Leaves were rehydrated in 3% phosphatebuffered
glutaraldehyde. For SEM studies the leaves were
dehydrated in an alcohol series, critical point dried, mounted on
stubs, coated with gold and examined with a Jeol Winsem 6400
microscope at 5 kV.