Pine Pollen

White Pine Pollen Collects in a Sidewalk Seam

By Jim Muratzki 

In spring, a fine yellow dust settles over the Grand Traverse region.  It causes sneezes.  It clouds the windows on cars parked outside.  It collects on the margins of drying puddles.  It blows into sidewalk cracks.  What is it?  It's pine pollen, especially from Michigan's state tree, the White Pine (Pinus strobus).

Staminate Cones (strobuli) on a White Pine

The pollen comes from the male, or staminate, cones that appear at the end of the pine tree's branches, giving it a starry look.  When the staminate cones release their pollen, the wind takes over, carrying the pollen to fertilize neighboring trees.  The female, or pistillate, cones near the top of the tree receive the pollen (White Pines have both male and female flowers on the same tree).  These will mature over the summer into long cones that will release seeds to the wind in the fall.  Some of these may take root, especially those buried by squirrels.

References:

U.S. Forest Service: http://www.na.fs.fed.us/pubs/silvics_manual/Volume_1/pinus/strobus.htm

Hiker's Notebook: http://www.mwrop.org/W_Needham/EasternWhitePine_060326.htm

All Allergy: http://allallergy.net/fapaidfind.cfm?cdeoc=1635

Chatooga Conservancy: http://www.chattoogariver.org/Articles/1999FW/Pinus.htm

Microscopic Photo: http://www1.fccj.org/dbyres/David/pollen100.jpg