In such interesting and painful ways. I’ve developed a sensitivity to the plants I study, and I don’t mean an appreciation for them. I mean that I react to exposure. Contact dermatitis haptens, yo.
The eglandular hairs of Boraginaceae are irritating, in the field and in the herbarium. The only good thing is that the stinging hairs aren’t urticating hairs, and don’t inject pain. So I can tell when I get a handful of Urtica dioica as opposed to Phacelia malvifolia or Phacelia nemoralis. The hairs are solid and break off and stay in my skin, and then I get itchy bumps.
The glandular hairs are a different irritating issue. I respond strongly to urushiol (Toxicodendron diversilobum) too, and sometimes it is really difficult to tell if the delayed contact dermatitis came from exposure to poison oak or glandular Hydrophylloideae taxa (like Phacelia pedicellata, Phacelia parryi, Phacelia crenulata, Phacelia minor, Phacelia campanularia…). Here is a pro-tip, NEVER ROLL AROUND IN A FIELD OF PHACELIA CRENULATA. It looks really pretty, but Phacelia crenulata smells like Phacelia crenulata, and then you will smell like Phacelia crenulata, and you have geranylhydroquinone everywhere.
so pretty. so shiny.
REYNOLDS, G. W., W. L. EPSTEIN, and E. RODRIGUEZ. 1986. Unusual contact allergens from plants in the family Hydrophyllaceae. Contact dermatitis 14(1):39-44.
REYNOLDS, G., and E. RODRIGUEZ. 1979. Geranylhydroquinone: A contact allergen from trichomes of Phacelia crenulata. Phytochemistry 18(9):1567-1568.
Via the Biodiversity Heritage Library and the Missouri Botanical Garden, Peter H. Raven Library. Eutoca multiflora Douglas ex Lindley, Botanical Register [Bot. Reg.] 14: tab. 1180. 1828. “A hardy annual, of great beauty, … resembling some small Echium in appearance”