The Malvaceae is a cosmopolitan plant family of about 80 genera and nearly 1500
species of herbs, shrubs and trees. The bisexual flowers have 5 petals, an
ovary with two carpels, and many stamen. Fruits may be berrys, samaras, schizocarps,
or capsules. The leaves are characterized by stellate hairs. Economically important
taxa include cotton (Gossipium), okra (Abelmoschus), and many ornamental flowers.
Pollen light micrograph:
The pores and spines are very distinctive allowing the grains to be readily identified
to the species or species-group level.
Pollen scanning electron micrograph (SEM)
The characteristic endopores are not visible in SEMs, but the frequent
separation of the inner and outer wall allows spectacular photographs
of the pollen wall structure.
Production and Dispersal:
This insect pollinated family has low production and poor dispersal, but
the plants are so widespread that a few grains appear in many samples.
Good. The walls are very thick, but can break apart.
Tertiary (Eocene) onward (Malvacipollis).
The Sphaeralcea-type, containing other genera, is