CarrotDaucus carota subsp. sativus
Apiaceae specialist — carrot foliage is among the canonical garden hosts for black swallowtail.
Apiaceae specialist — parsley is the canonical garden host for black swallowtail caterpillars.
CeleryApium graveolens var. dulce
Celery is a carrot-family (Apiaceae) plant, and University of Wisconsin-Madison Extension documents that black swallowtail (Papilio polyxenes) caterpillars feed on cultivated dill, parsley, fennel, celery, caraway, and carrot in backyard gardens — where the caterpillar can even be considered a pest.
Black swallowtail caterpillars host on carrot-family plants (Apiaceae) including dill, fennel, parsley, and carrot; chervil is the same family and is a plausible occasional larval host when left to flower, though far less documented than the core Apiaceae hosts.
Black swallowtail caterpillars host on members of the carrot family (Apiaceae) including dill, fennel, parsley, and carrot; cilantro is the same family and is a plausible occasional larval host when allowed to flower, though it is far less documented than the core Apiaceae hosts.
Dill is a larval host plant for the black swallowtail butterfly — both the Missouri Botanical Garden PlantFinder and the NC State Plant Toolbox name it specifically as a larval host. The caterpillars feed on the lacy foliage of dill and other carrot-family plants before pupating into swallowtails.
Fennel is a larval host plant for swallowtail butterflies — the caterpillars chew on the foliage and morph into swallowtails (Missouri Botanical Garden PlantFinder; NC State Plant Toolbox). The black swallowtail is the classic Apiaceae-feeding swallowtail whose larvae feed on fennel and other carrot-family plants.
Missouri Botanical Garden PlantFinder names golden alexanders as a food plant for the larvae of the black swallowtail (and Ozark swallowtail) butterflies; the Lady Bird Johnson Wildflower Center lists Black Swallowtail (Papilio polyxenes) as a larval host use.