Winter Pollen

J. ashei pollen is spherical (top left) and has small granular elements on the surface as can be seen in the scanning electron microscopy photo (bottom right). During pollen release the male cones on the tips of the branches (bottom left) ripen and large clouds are released into the atmosphere (top right). In areas where dense populations grow (below), the pollen clouds are extensive and can often be seen with the naked eye, even though the constituents are microscopic.

The main pollen producer in Oklahoma during the winter season is Juniperus asheii. Populations grow in southeastern Oklahoma in the Arbuckle Mountains, and in northeastern Missouri in the Ozark Mountains, but the largest populations occur in south central Texas on the Edwards Plateau as shown on the map of Texas. Long-distance transport of J. asheii pollen into Oklahoma is currently under study and efforts to forecast these incursions are occurring during the pollination season.