Pollen grains are highly variable in size and shape ranging from 5μ to over 200μ in diameter and from circular to tetrahedral or dumbbell shaped.
Pollen grains are highly variable in size and shape ranging from 5μ to over 200μ in diameter and from circular to tetrahedral or dumbbell shaped.
花粉粒的壁由两层构成，外壁为孢粉素壁，具有很强的抵抗力，其上有特征性雕纹或孔纹。