ONCE, IN MY HALCYON COLLEGE DAYS, I TOOK A BOTANY CLASS.

Everything was interesting to me then. Kind of like now, except I was 24.

Following a long-standing habit of late bloomers, I enrolled in my first college courses in Santa Barbara a full six years after graduating from high school.

And, due at least in part to my ho-hum high school experience, every course was a wonder. Sociology! History! Psychology!!

And botany! The scientific study of plants! Man!

“Plants,” I learned, as though a true revelation, include a wide range of living organisms, from the smallest bacteria to the largest living things — the giant sequoia trees. By this definition the classification comprises algae, fungi, lichens, mosses, ferns, conifers and flowering plants.

Big wow.

And California botany at that! This would be way different from Oklahoma botany.

Oklahoma botany, to my childhood recollection, included mainly waving wheat, like in that song; assorted grasses dominated by the crab and Bermuda varieties; and the occasional tumbling tumbleweed, if you found yourself out in the Panhandle drifting along — like in that other song.

Oh, we had trees — but not like California! We had elm trees and maples just like everyone else in the continental U.S. Big deal. The most exotic tree I encountered as a child was a mimosa.

Once I got caught in the cross-fire of a whipping my grandma gave my cousin with a “switch” from her willow tree. There’s a lesson in botany.

But California has redwoods! And ice plant and bougainvillea and, and …

Poison oak.

Now in Oklahoma, I encountered poison ivy often enough to know my way around a bottle of calamine lotion — like in that song! I learned by way of miserable nights not to scratch because fingers were conspirators in poison ivy’s plot to take over a skinny girl’s body.

I knew to let the pink stuff dry and curl up and flake away like so much sun-beaten paint.

And, like a prepubescent cut-rate contractor, I slathered on second and third creamy coats of that cool substance to fields of blisters without sanding, so that I wound up with a thick paste caked on my ankles and wrists and the insides of my elbows and the backsides of my knees.

Sumac could raise a field of bubbles too. So I learned to identify and cut a wide perimeter around both those sinister plants.

That was my plan with the poison oak my botany instructor spoke about prior to our field trip freshman year. We were going to trek along the Santa Barbara hills and document our botanical finds.

Turns out, we didn’t see any poison oak that day. But I got it.

I repeat: We never found a single poison oak plant — but I broke out with an impressive cluster of itchy bubbles.

All these botanical bad dreams resurfaced this week after Mr. Plath cleared the hillside below our house of cacti — to the tune of 30 truck-loads of prickly arms, joints, ribs and barrels — along with wild fennel, palm debris, scrub plants of unknown varieties and — you guessed it — poison oak.

I should mention that Mr. Plath is among those happily oblivious folks who wander the jungles and deserts and tangled woodlands of the world without fear. He is not allergic to the virulent plant. Isn’t that just great?

But he took extreme precautions at my urging: long sleeves and pant legs, gloves, glasses. When the task was complete, he tiptoed into the laundry room like a burglar, touching no surface, leaving no trace. He stripped down and put his radioactive clothing straight into the washing machine on hot, with bleach.

We circumnavigated each other in the hallway with arms overhead like two crabs vying for the same stretch of sand. Hey! Hey! Hey!

He didn’t even chance to give me a peck on the cheek, which he ALWAYS does when he passes within range. Directly into a decontaminating shower he went and scrubbed down as though for surgery.

All the while, I stood by in my own hermetically sealed hazardous waste jumpsuit.

And still I got a nice big dose of the nasty stuff.

Oh the irony! Oh the chagrin! Oh the recriminations!

Oh darn.

Carolyn Plath is a Benicia resident and retired high school principal. Read her blog at thinkdreamplay.blogspot.com.