'Tis the Season!

The annual grasses have suddenly gone from "the golden rolling hills of California" (Kate Wolf) to a kind of burnt reddish hue. Things are really dry, but WAIT! There really are still wildflowers to be found! On a short hike up North Burma over to Lake Ilsanjo on Tuesday I found Spanish Clover with delicate tiny pink blossoms, pennyroyal still blooming in profusion along the lakeshore, Fitch's Spikeweed (taking on the look of something sinister like yellow-star thistle but more friendly). And it's now the season of GALLS!! I wasn't looking really hard for them yet, saving myself for the California Biodiversity Week bio blitzes, but one just one Valley Oak I found 5 species of galls all within my 5'1" reach.

I tend to find the most diversity of galls on Oregon Oak and Valley Oak trees. It seems to me that I more often find galls on the west exposure leaves of the oaks. Maybe I am just making this up? Certainly there must be influences for a gall wasp in wind direction, light/sun exposure for the galls and hatching young, even the direction or availability of the breeze to the newly hatched young for proper dispersal. Am I over-thinking this? Nature always has an intricate plan.

Look for galls usually on the underside of leaves -- so get up close and personal with the tree. Don't worry: if you are new to looking at galls, the gall wasps are tiny no-see-ums and don't bite or sting, but leave wonderfully creative and colorful "nurseries" growing on the leaves in which their eggs can grow. Get ready to be WOW'd.

If you are really into observing, documenting and learning more about galls, check out the gall iNat projects: Galls of California and Galls of North America. A great field guide (though a tad heavy to actually carry in the field) is Ronald A. Russo's "Plant Galls of the Western United States" (2021: Princeton University Press). He incorporates very clear beautiful full-color photos and great descriptions in sections according to gall types, as well as a section titled "The Gall-Inducers" describing the species who create the galls.

Posted on August 30, 2024 04:11 PM by wildmare64