It consists of an air-filled protuberance on each side of the pollen grain developed by the separation of the exine layers, giving the pollen a characteristic winged appearance.
Each lobe contains two pollen sacs that produce very large quantities of small pollen grains.
The mean number of pollen grains per stigma is 8—12 Most of the pollen grains are from self pollination. The pollen vigour is strong in the pollinating period.
A microscopic fossil, as of a pollen grain or unicellular organism.
pollen grains germinate directly on the stigma
The results from the pollen densitometers indicate the number of pollen grains sucked into a device per square millimeter of the aperture.
In present work, the development of anther, formation of pollen grain and development of ovule and formation of embryo sac in Ramie were observed.
Both the pollen grains and the gynoecia are active.
It has been magnified 115 times, but it contains long hairs such as cat fur, twisted synthetic and woollen fibres, a pollen grain, plant and insects.
The innermost wall of a spore or pollen grain.
In 1827, upon observing a suspension of pollen grains in water, he discovered BROWNIAN MOTION.
The probability of any air-borne pollen grain impacting a female strobilus is in any case very small.
2) The incidence of pollen grains abortion is 40.48±2.33%.
Their sterility showed no pollen grains, anther could not been shed, anther couldn't shed pollen.
