The best known predator of Wild Carrot in eastern North America is the Black Swallowtail (Papilio polyxenes), the caterpillar larvae of which feed on a range of plants in the carrot family (Apiaceae, formerly Umbelliferae), as well as the citrus family (Rutaceae).(Wagner 2005)
Wild carrot (Daucus carota carota), also known as Queen Anne’s lace, is native to temperate regions of Europe and western Asia, and has been introduced into America, New Zealand, Australia and Japan. It is sometimes viewed as a problematic weed at least in its non-native range. (Rong et al. 2010 and references therein).
Wild Carrot is found in a range of habitats, but especially dry fields, roadsides, and other disturbed areas.
Chromosome number is 2n=18 (Gleason and Cronquist 1991).
Wild carrot (D. carota carota) is native to temperate regions of Europe and western Asia, and has been introduced into America, New Zealand, Australia and Japan (Rong et al. 2010 and references therein).
Wild carrot is found throughout the eastern states and along the south and west coasts of the United States, in Canada, Mexico, Central America, and the West Indies. It occurs throughout the British Isles, where it is especially abundant near the sea. It also occurs from Norway and central Sweden south to North Africa and the Canary Islands, and eastward through Siberia to northern and eastern India. (Mitich 1996 and references therein)
Although Wild Carrot is often referred to as a biennial (growing as a rosette of basal leaves one growing season, then growing upward, flowering, and dying the next), in fact its life history depends on the environmental context (e.g., what time of year the seed germinated, nutrient and light availability, competition). Under good conditions, germination may occur in the spring and the plant may flower in late summer of the same year. Under poor conditions, the rosette may grow for several years before the plant flowers. When flowering occurs, the topmost flowers in the umbel (a broad, flat type of flower cluster) generally mature and develop seeds first. New flowerstalks are produced from the basal rosette throughout the growing season, which makes Wild Carrot unusually resilient to mowing. Once the flowers are pollinated, the umbel closes in on itself and dries out as the seeds mature. (Stokes and Stokes 1985).
There are around 5 dozen Daucus species worldwide (Gleason and Cronquist 1992). In the northeastern United States, there is one other Daucus, D. pusillus, which is widespread in the southern U.S. In contrast to D. carota, D. pusillus has involucral bracts that are not scarious-margined (scarious-margined below in D. carota) and that are appressed to the umbel in fruit (spreading or reflexed in D. carota). (Gleason and Cronquist 1992)
A number of other members of the carrot family--including some dangerously poisonous ones--bear some resemblance to Wild Carrot. For example, Fool's Parsley (Aethusa cynapium) and the Poison Hemlock (Conium maculatum) that supposedly killed Socrates could be confused with Wild Carrot (both of these plants, however, have hairless stems and unpleasant-smelling foliage, among other differences). (Stokes and Stokes 1985)
Wild Carrot grows to around 60 to 120 cm in height. The first year, it typically grows just a basal rosette with a deep taproot. Stems are erect, hollow, stiff-haired, and sometimes branched. Leaves are alternately arranged, stalked near the base and sessile above. Twice pinnately compound leaves have narrow segments to around 13 cm in length. Leaf margins and veins have short hairs. The five-petaled white flowers are grouped into a flat-topped inflorescence (an umbel) 8 to 16 cm wide. The seeds are around 3 mm long and grayish brown, with one side flattened and one side rounded with distinct ribbing. Mature seeds have barbed prickles. (Whitson et al. 1991)
Each tiny flower in a Wild Carrot umbel has five irregularly shaped petals. The flowers on the outer edge of the umbel often have larger petals, perhaps to make the umbel more conspicuous to pollinators. Each flower has five tiny threadlike stamens (the male parts) and most also have two pistils (female structures), but these are too small to be seen with the naked eye. Although the flowers in each umbel have both male and female parts, the inner flowers are functionally male only. In the center of many Wild Carrot umbels there is often a purple, sterile flower, the function of which (assuming it is adaptive) is unknown. After flowering and going to seed at the end of the growing season, the whole plant dies, but the flowerstalks often remain, dispersing seeds through the winter. (Stokes and Stokes 1985)