Quercity—Thoughts on Oaks

Coast live oaks, Quercus agrifolia, in the California Coast Range.

Free time has been scarce lately, so I’m offering a short post on oaks, inspired by “Querc-y Characters” at the Lady Bird Johnson Wildflower Center website.

I have a fondness for the Wildflower Center that surfaces at the least provocation, for I once talked plants with Lady Bird! It was 40 years ago, when I was botanist and sole employee of the Wyoming Natural Diversity Database. Jane Sullivan, wife of the governor, invited a small group of botanically-inclined ladies to gather for tea with Mrs. Johnson in Jackson Hole, at the base of the Grand Tetons. Conversation was awkward at first, but Lady Bird had done her homework, and as we introduced ourselves, she responded with what she had heard or read about our work. Soon we were happily discussing plants. Afternoon tea is not my idea of fun in the Tetons—I prefer hiking. But I really enjoyed my time with Lady Bird. She was so gracious and down-to-earth, a wonderful mix.

Now to the oaks …

Bur oak leaves, Dugout Gulch Botanical Area in the Black Hills.

In Wyoming, we have two oaks, both at the edge of their range here. Bur oak, Quercus macrocarpa, is a tree of the eastern and midwestern US that reaches its westernmost extent in northeastern Wyoming, mainly in the Black Hills. Gambel oak, Quercus gambelli, is common in Colorado and the southwestern US, but in Wyoming it grows only in the Sierra Madre, near Colorado. I was going to add “northernmost extent” but when I checked the NRCS PLANTS Database distribution map, I discovered that Gambel oak has been reported from South Dakota! However, there’s no county recorded, and the Forest Service FEIS treatment doesn't mention South Dakota. This would be a major disjunction, and news to me. But it’s an oak matter for another time.

Gambel oak; source.

In a way, we’re lucky we have just two oaks in Wyoming. I worked several winters in southeast Arizona, and struggled with the oak situation there. Apparently it’s even worse in Texas … or better, if you're not obligated to come up with identifications. Texas has more oak species than any other state in the US. Amy McCullough has put together an elegant straightforward guide to four of the common ones in Central Texas: Querc-y Characters, illustrated by Samantha N. Peters. Besides being a work of art, it shows clearly the characters and challenges in oak identification.

If you’re a hardcore oak fan, or looking for a botanical adventure, check out Quercus in the Flora of North America (FNA). There are 90 oak species in North America according to taxonomist Kevin Nixon, who prepared the FNA treatment. The exact number is debatable because oaks hybridize readily. “An astounding number of hybrid combinations have been reported in the literature, and many of these have been given species names, either before or after their hybrid status was known. … Hybridization in most cases results in solitary unusual trees or scattered clusters of intermediate individuals.” Oh dear!!

Even if you’re not up for a Querc-y Mega-Challenge, you might find Nixon’s introduction interesting—a revealing glimpse into the tortured world of oak taxonomists.

“A representative selection of mature sun leaves” is required for oak identification. Shade leaves won’t do. These are leaves of the coast live oak—sun above, shade below.

Acorn atole -- not a convenience food

Coast live oak near San Luis Obispo, California.  Photo by Giovanni LoCascio, used with permission.

The theme for March’s Berry Go Round is unusual edible plants, and all month I’ve had my ear to the ground for ideas.  Then last week while in California I read about Indians collecting, preparing and eating acorns.  I was struck by the oddity of it all.  I chose the coast live oak as my unusual edible plant but when I started to write, I realized there wasn't anything unusual about it.  Coast live oaks are common and the acorns are commonly eaten by wildlife.  They also were used by Indians to make a thick soup or mush, which the Spaniards called “atole” (ah-toé-leh) back in the 1700s.  It’s said to have been one of their most common foods.

Acorns of the coast live oak, Quercus agrifolia, were among the most prized for making atole.  Source

But times have changed and therein lies the explanation for why the oak seems an unusual edible plant.  In my world we rarely think about eating to survive.  Instead we search for food that's tasty, and usually convenient to prepare.  We wouldn't bother with acorn atole.

In fact, compared with atole, everything I eat is convenience food!  Converting tough bitter acorns to something edible was a long and tedious process.  Here’s a typical recipe, compiled from several sources (italics added for emphasis):

In fall, if the oaks have produced acorns, collect as many as possible, at least several hundred pounds.  Dry thoroughly in the sun and store.

Remove a small batch of acorns from storage, enough for the day.  In a stone mortar, grind a few at a time using a pestle or any suitable stone. When all acorns are ground, sift or winnow meal to remove coarse material.

Put the meal/flour in a depression in sand.  Rinse repeatedly with water.  This will require the greater part of a day unless hot water is available.  [Leaching removed bitter tannins.]

Pull out the sand-free center of the dough and bake as bread.

Use the remainder of the dough to make atole.  Mix with water in a woven bowl.  Drop in hot stones, stirring frequently to prevent scorching of the bowl.  Cook until desired consistency is obtained.

Methods of preparation varied somewhat.  Here Maggie Howard, a Paiute, shells and skins acorns into special baskets (Sierra Nevada, 1930s).  Elsewhere, acorns were simply dried and stored whole.  Source

“Grinding acorn meal.  A modern-day Indian woman gives a demonstration of the technique and tools employed by her forebears ...”  Source

Was atole tasty?  If so, maybe it was worth all that effort.  Saunders (1920) described the flavor as “rather flat but with a suggestion of nuttiness that becomes distinctly agreeable.”  Balls (1972) said it had a “slightly sweetish but rather insipid taste.”  Some visitors had problems with residual sand from leaching, and ash from the cooking stones.  But I think it's impossible for us to judge atole's appeal.  That was a place and time of limited fare, quite unfamiliar to us.

In any case, there were other reasons to eat atole.  Acorns are nutritious and rich in calories, especially compared with many wild plants.  They contain “up to 18 percent fat, 6 percent protein, and 68 percent carbohydrate” (CSUS no date).  They're large, and fairly easy to harvest.

Still, I was skeptical when I read that atole was an important staple, because acorns are so unreliable.  Oaks produce substantial yields only during mast years and these are unpredictable (Harper et al. no date).  This is good for the oaks.  During mast years, seed predators generally are swamped with food, and it's likely that some acorns will produce seedlings rather than be eaten.  However human seed predators had a counter-strategy -- storage.  Dried acorns are long-lasting, and Indians regularly stored them for several years or more (one source says up to a dozen).

Acorn woodpeckers also store acorns, but not as effectively as humans once did.  This one is stocking a "Granary Tree".  Source

Acorn atole has not disappeared.  It’s still prepared on special occasions, as a link to the past and in celebration of traditions and culture.  Fortunately, today’s cooks have access to modern conveniences:

“instead of the mortar and pestle, the electric blender or a meat grinder may be used to produce flour.  Cloth might substitute for the leaching basin, buckets may replace baskets, and a slow drip in the kitchen sink may flush the tannic acid.  For cooking, the stove and a metal pot might replace heated stones placed in baskets.  Whatever the preparation techniques, acorn is special: a tangible connection to the old ways, a nourishing food, and a commitment to the future” (from Past and Present Acorn Use in California)

Modern day mortar and pestle for making atole.  Source

NOTE:  Acorn atole is not related to the atole of Mexico, which is made from corn.

This month's Berry Go Round is hosted by Emma the Gardner.

Sources

Balls, E.K.  1972.  Early uses of California plants.  University of California Press.

California State University, Sacramento (CSUS).  No date.  Past and present acorn use in native California.

Harper, J.M. et al.  No date.  Acorn production by California oaks.

Saunders, C.F.  1920.  Useful wild plants of the United States and Canada.  New York: McBride & Co.

What’s an old oak for?

Coast live oak and swing; photo courtesy Giovanni LoCascio.

What’s an old oak for but to swing on,

back-and-forth back-and-forth,

my mind runs wild!

or simply wanders ... dreaming.

Then the child is gone.

Branches of coast live oak decorate the California sky.

Where does this chain go?

To a swing of course!

As kids we spent many hours on this swing, back-and-forth, higher-and-higher, trying to touch the oak, wondering if the rusty nails holding the chains together would break (neither happened).  It is one of many in a neighborhood of oaks perfect for swinging.

Swings on live oaks -- "live" because they have green leaves year-round.

Not all coast live oaks reach swingable stature.  I remember a surprising encounter with one as a Botany Novitiate.  We were receiving the Teachings of the Order on a steep rocky slope covered with chaparral, examining leaves of woody shrubs, speaking knowingly in Latin. The concave leaves with spiny margins belong to Quercus agrifolia, the coast live oak ... what?!  Yes, sometimes the wisdom we are given is not what we expected.

Left:  coast live oak growing in full sun.  Sun leaves are small and thick, with extra photosynthetic cells to maximize solar gain.



Below:  shade leaves.

The coast or California live oak is the most variable tree I know of.  There are well-formed oaks dotting grasslands on hills, tall oaks in canyon bottoms with a maze of high branches reaching for the sun, and stunted oaks on steep dry rocky slopes.  Among the most charming are those that grow bending and winding for centuries but never get very tall, avoiding the sea winds by staying in the shelter of the canopy.

This Los Osos oak has grown wide instead of tall. 

Forest of stunted coast live oaks at Los Osos Oaks SNR.

Though modest in size, the oaks of Los Osos Oaks State Natural Reserve are thought to be 600-800 years old!  On more favorable sites they sometimes reach 25 feet in height.

An easy 2-mile trail winds through fantastical oaks.

A mighty oak hugs the ground -- this is not an oak for swinging!

So let's go back to that canyon bottom with all the gnarled old oaks and swing for a bit, back-and-forth, higher-and-higher, and see where it might take us.

Maybe we will find our dreams!  And maybe now that we are big, we will touch the sky ...

From The Swing by R. L. Stevenson.

How do you like to go up in a swing,

Up in the air so blue?

Oh, I do think it the pleasantest thing

Ever a child can do!