Acorn or Gall? 

An Albuquerque Park Mystery #26

September 6, 2026

The date: August 24, 2026 

The time: 8:30 am. 

The forecast: Severe clear; calm winds; 82^oF & climbing

The place: The Promenade in Albuquerque  

The destination: el Oso Grande Park (“The Big Bear”)

After dropping Roy off for his annual eye exam, Luna and I decided to ‘sniff’ around the neighborhood on our way to nearby el Oso Grande Park. With the chance of rain being “zip,” I was confident walking east along a half-mile stretch of the large cement ditch used to drain storm water from Embudito Canyon. Other than creatively colorful graffiti, the ditch itself had nothing interesting to offer. The hot paved walkway, mostly lined by weedy species, provided perfect habitat for scattered bushy sacred datura plants in full bloom. The many city dwellers living ditch-side allowed landscaping plants to cascade over cinderblock privacy walls — the patches of shade – welcome; sprays of pale pink to magenta desert willow flowers – pretty and fragrant.

A sweaty 20 minutes later and the shady expanse of the Park was a welcome sight. Not one to waste time, Luna anxiously led me to tree trunk #1, circling and sniffing excitedly three times ‘round. Not being able to smell the wonderfully curious aromas capturing her full attention, I spent my time looking up into the leafy canopy of this full grown deciduous tree planted years ago in memory of a once local resident.  

We moved on to tree #2, a robust conifer towering over the well-manicured green lawn, supported by another aromatic trunk recently ‘watered’ by a happy dog walking their human. Before we could check out tree #3, Luna claimed #2 by leaving her ‘calling card.’ 

And on and on we wandered and circled, until ….

…. I realized, based on our exam speed/tree (largely driven by Luna’s satisfaction meter), our Park tour of over 100 trees would take a month of Sundays! So we ramped up our pace, making  decent progress to (hopefully) ensure our timely return to fetch Roy …. then tree #26 happened! 

Oh! What was #26? Now it was my turn to encircle a tree, and I couldn’t stop.  In addition to the puzzled look on Luna’s sweet face, several other things were certain: 1– this very large tree was a 2– deciduous 3– dicotyledonous member of the 4– oak genus Quercus. The deeply-lobed leaves were a giveaway, even though most of each leaf’s margins were dried and crinkly. But it wasn’t the leaves catching all of my attention — it was the 1-inch diameter shaggy pale green balls growing from the ends of many leafy branches. This certainly didn’t look like any acorn I’d ever seen before …. besides, right beside this scary-looking tentacled orb was a single mini-acorn that tried but never fully developed — only the dried, withered acorn cup had partially formed before rotting. 

So what was it that sucked the life right out of that tiny failed acorn, and grew into something alien?  If this was some kind of acorn that grows on a non-native oak tree I’ve never seen before, then I had to learn more! If this was a gall, an unusually grotesque, weird and exaggerated growth stimulated by a developing wasp grub living deep inside, then I really had to learn a lot more! 

And then I collected and promptly zip-locked a specimen.

This became (and still is) An Albuquerque Park Mystery hanging like lime green ornaments all over, and also within reach from, tree #26!

P.S.

• iNaturalist identified the tree as Gambel’s oak 
• Never have I ever seen a Gambel’s oak acorn look like that!
• Still waiting for an oak expert to identify the tree leaves and/or acorn/gall-thing

P.S. P.S.

• So many questions remain
• Upon arriving home, no wildlife observed inside zip-locked bag
• I dissected the growth, inside and out — found what looked like an acorn nut 
• No sign of a grub; no exit holes in the outer or inner shells

P.S. P.S. P.S.

• Luna & I practically ran back to the eye doc’s office, arriving minutes before Roy’s exam concluded

……………………………………………………………………………………..

If you’ve seen anything growing on an oak that remotely resembles these mystery green goblins, please let me know what it may be, and what species of oak they come from! 

As always, thanks for stopping by!

P.S. P.S. P.S. P.S.

• When “An Albuquerque Park Mystery #26” is solved, you’ll be the first to know!