The hilly redwood forests of Santa Cruz are home to a spectacular gastropod, the Slender Banana Slug (Ariolimax dolichophallus). These sulfurous-yellow slugs are large: many are over six inches long. They creep through the forest floor and across trails in broad daylight, munching on fallen leaves, fungi, and low-growing plants. Apparently, they don’t eat redwood seedlings, so they keep the competition down in the understory, helping the redwoods to regenerate.
A general rule of natural history is that brightly colored animals that wander around in the open without any visible means of defense or escape are likely to be poisonous in some way. As far as I can tell, the chemical ecology of banana slugs has not been fully analyzed, but among Santa Cruz naturalists there is a tradition of experiential investigation of these slugs, an experience that is mediated through the tongue. So, eager to join the inner circle of initiates, I genuflected then prostrated myself before a large specimen on the trail. The animal was strangely unperturbed by my licking. The same could not be said about my tongue. I did not taste much in the way of noxious secretions, but for half an hour afterward I had a layer of gelatin firmly adhered to the top of my tongue.
Following this encounter, I learned that the tangy stalks of redwood sorrel (Oxalis ¿oregana?) do a great job of “cleansing the palate” (an expression that I believe originated somewhere a little more classy than among the Ariolimax-lickers of California). For those of you whose thoughts are turning to hallucinogens: you’re thinking of toad-licking. Believe me, lying flat out on a redwood forest floor licking a giant yellow slug is experience enough for me. What could a hallucination possibly add?
The slug is endemic to the Santa Cruz area (two other species are found elsewhere on the west coast) and is the mascot of UC Santa Cruz. The T-shirts say: “Banana Slugs: No Known Predators” which is catchy but not entirely true. The less well-informed Pacific giant salamanders eat them, as do snakes and some other creatures.
I looked into Mead’s original 1943 description of this species and the diagnostic character is the length of the penis: “not infrequently of greater length than the slug itself.” Mead was so breathless with amazement that he added an exclamation point in the scientific description, a form of punctuation that is as rare as the smiley face in taxonomic journals. Quite why the famously enterprising undergrads of UCSC have not developed a T-shirt emphasizing this zoological phenomenon in their hermaphroditic mascot, I don’t know.
Thank you to my friend and former student Leighton Reid for being my host for this visit and guiding me in the ways of the banana slug.