1. Daucus carota L. ssp. carota (Queen Anne’s lace, wild carrot)

Pl. 206 i–k; Map 854

Stems 40–150 cm long. Leaf blades 5–20 cm long, the ultimate segments 2–12 mm long, 0.5–2.0 mm wide. Involucre with the bracts 4–40 mm long, spreading to loosely ascending at flowering, spreading to loosely reflexed at fruiting. Rays 3.0–7.5 cm long, spreading to loosely ascending at flowering, curving upward and inward at fruiting, the umbels thus becoming more or less oblong in outline as the fruits develop. Involucel with the bractlets (or their lobes) linear, with broad, thin, white margins, at least toward the base, appressed-ascending at fruiting. Flowers sessile (the central flower in each umbellet) or the stalks 1–8 mm long. Fruits 3–4 mm long, the mericarps with the flattened bristles of the winged secondary ribs usually very minutely barbed or hooked at the tip (barely visible at 10× magnification), appearing merely pointed at lower magnification. 2n=18. May–October.

Introduced, common nearly throughout the state, except apparently uncommon in the Mississippi Lowlands Division (native of Europe, Asia; naturalized widely in North America, Central America, Caribbean Islands). Banks of streams and rivers, tops of bluffs, glades, and occasionally mesic to dry upland forests; also margins of crop fields, fallow fields, old fields, pastures, fencerows, roadsides, railroads, and open, disturbed areas.

Daucus carota is a polymorphic species consisting of several closely related subspecies (St. Pierre et al., 1990), notably ssp. carota (Queen Anne’s lace), and ssp. sativus (Hoffm.) Arcang. (cultivated carrots). There are numerous carrot cultivars differing in root size, shape, and color, but all possess expanded taproots rich in starch and sugar, and most have yellowish corollas. Carrots also are high in beta carotene, which is converted easily into vitamin A in the human digestive tract, and in addition to its consumption raw, cooked, or baked, the subspecies is a commercial source of carotene for dietary supplements. The inflorescences of ssp. carota are sometimes used fresh as cut flowers or dried in floral arrangements. However, this weedy subspecies can produce furanocoumarins that may cause phototoxic dermatitis in some individuals. There is disagreement on whether ssp. carota should be considered mildly poisonous, but it is known that plants are capable of producing a series of polyacetylenes (see the treatment of Cicuta), principally falcarinol, that act as natural pesticides and have been documented to cause mild symptoms in livestock in Europe. Steyermark (1963) noted that the milk from cows grazing on Daucus has a bitter flavor. Several trivial color mutants of Queen Anne’s lace have been named as forms, including those with all of the flowers pink to purple (f. roseus Farw.) and those with all of the flowers white, including the central flower of each umbellet (f. epurpuratus Millsp.).