Flora Fact: Toothy Chew
The toothache tree eases pain and hosts swallowtails.
By Sheryl Smith-Rodgers
When Ralph Arvesen explores his family’s land in the Hill Country, he often shares the biology of native plant species with his daughters.
“One time, I picked some bull nettle and showed Kaitlyn and Makayla how my skin reacted when I brushed it against my arm,” recalls Arvesen, a software engineer who lives in northwestern Blanco County. “When I spotted a little toothache tree, I explained how the species got its name, then I chewed on a leaf. That day, I returned home with a numb tongue, gum and lips — and a swollen arm!”
Instead of leaves, Comanches and other Native Americans chewed the tree’s bark to dull a throbbing tooth. Warty, knobby spines cover the trunks of older trees — hence its other vernacular names of Hercules’ club and prickly ash.
Four species of Hercules’ club, prickly ash or tickle-tongue range in Texas. Zanthoxylum clava-herculis is most common in the state’s central and eastern regions, says Mike Arnold, a horticultural professor at Texas A&M University, while Z. hirsutum is more common in the western half of the state. The southern part of the state contains Z. fagara, and the rare Z. parvum is found only in two West Texas counties.
In spring, Hercules’ club — found in fencerows, near rivers and at the edges of woodlands — puts on clusters of green flowers. After ripening, the tree’s brown seed capsules get eaten by birds. Ugly caterpillars resembling bird droppings dine on the tree’s leaves, then morph into lovely giant swallowtails (Papilio cresphontes).
FYI: Devil’s walkingstick (Aralia spinosa), a spiny shrub, is also called toothache tree, prickly ash and Hercules’ club. Thank goodness for botanical names!