Background

We looked at this article which said that cold temperatures can affect the pollen of plants. Cold temperatures are needed for many plants to bloom.

http://www.desertmuseum.org/programs/flw_predicting.php

This article said that when plants have less water during flowering time, the pollen is larger and more spherically shaped. We thought this might apply to winter flowering plants because there is less rainfall during winter than there is during spring.

http://www.academia.edu/2393597/Does_climate_affect_pollen_morphology_Optimal_size_and_shape_of_pollen_grains_under_various_desiccation_intensity

This article said that the pollen of spring pollen was different in form and size from summer flowering pollen.
http://www.doiserbia.nb.rs/img/doi/0354-4664/2012/0354-46641201085B.pdf