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Marin County | Plant Groups

Marin Acorns
Acorns are a great way to identify an oak, because they’re pretty easy to tell apart. Here is a picture list of common acorns found in Marin. Thanks to Wendy Dreskin (WD) for her acorn samples and clever ways to remember them.
Coast and Interior Live Oak Quercus agrifolia and Quercus wislizeni Extensive range in Marin Beech Family Native	· Skinny acorn, often with extended point. · Shingle-style cap · Interior cap tends to cover a lot of the acorn, compared to Coast. · Interior Live Oak acorn can grow in the middle of a stem because it lasts 2 years.	Acorn cap looks and feels like rough shingles.	Long, skiny, pointy acorn.	Acorn growing mid-stem makes this an Interior Live Oak.
Tanbark Oak Notholithocarpus densiflorus Slopes Beech Family Native	· Crazy hair cap. · Hard woody nut shell. · Roundish acorn.	Cap like crazy hair. This one looks like dreadlocks.	Roundish acorn.	Cap can be covered with short spines.
Canyon Live Oak Quercus chrysolepis Canyons and slopes Beech Family Native	· Top like a beret, coming around the sides of the acorn more than the beanie of the Blue Oak. · Acorn is less long than the Blue Oak.	Cap smooth but slightly bumpy to the touch.	Cap reaches around sides of the acorn.	Leaves are tough and thick like other live oaks.
Blue Oak Quercus douglasii Valleys and lower slopes Beech Family Native – found only in California	· Cap covers just the end of the acorn. · Cap looks like a beanie. · Cap smooth but slightly bumpy to the touch.	Cap looks like a beanie.	Cap sits on top of the acorn.
Leather Oak Quercus durata Dry, higher exposed slopes. Beech Family Native – found only in California.	· Often two acorns at the end of a stem. · Top of cap has rough bumps on it. · Leaves are thick, often fuzzy, and curl under.	Cap has increasingly rough bumps near the top.	Cap at end of stem.	Leaves very tough and curled over.
Black Oak Quercus kelloggii Lower elevations Beech Family Native	· Top is like shingles, and covers more than half of the acorn. · Run your fingers over the top - the cap is smooth. · Black Oak leaves are quite red in the spring, and always have points at the end of their lobes.	Cap covers more than half the acorn	Smooth top in layered shingles.	Spring leaves red. Leaf lobes always pointy.
Valley Oak Quercus lobata Lower slopes Beech Family Native – found only in California	· Top has hills and valleys (Valley Oak, get it?) · Run your fingers over the top – the cap is bumpy but not rough. · Cap covers less than half the acorn.	Brown nut has a dull point at the end.	Cap has deep valleys and smooth tops.	Here is a green (newly developed) acorn.

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Reviewed by DLS. Last Updated 3/24/2014 by BHS.

Note to botanists – this page uses common vocabulary, sacrificing more precise scientific terms in the interest of general communication. We hope the loss of precision in wording is, to some extent, made up for by photographs showing key identification points.