Goutweed is a popular groundcover that has gone native. It likes shade and damp areas, and it can take over large tracts of wet forest. The compound umbels (that is, flat-topped clusters of flat-topped clusters) of flowers will remind you of its relative Queen Anne’s Lace (Daucus carota); the leaves bear a superficial resemblance to elderberry leaves, and the flower umbels to elderberry umbels, whence Goutweed is also known as Ground Elder. It blooms in late spring. Some of the plants in these pictures were found in Bird Park, Mount Lebanon, and the others in West End Park.

The plants are similar to Spotted Cowbane (Cicuta maculata), and Father Pitt has misidentified them in the past. Here are differences to look for:

Spotted Cowbane has purplish stems or stems “streaked with purple” (says Gray); Goutweed has green stems.

The stalks of Spotted Cowbane are fatter than the stalks of Goutweed.

The flower clusters or “compound umbels” of Spotted Cowbane are more numerous and sloppier (“pedicels very unequal”) than the compound umbels of Goutweed.

Finally, Goutweed tends to grow in large and dense colonies, which is why it was popular as a ground cover.

Gray describes the genus and the species:

AEGOPÔDIUM L. GOUTWEED. Fruit ovate, glabrous, with equal filiform ribs, and no oil-tubes; stylopodium conical and prominent; seed nearly terete. — A coarse glabrous perennial, with creeping rootstock, sharply toothed ovate leaflets, and rather large naked umbels of white flowers. (Name from aix, goat, and podion, a little foot, probably from the shape of the leaflets.)

A. podagrària L. —Waste-heaps, etc., e. Mass. to Del. (Adv. from Eu.) [It has since spread further, mostly by escaping from gardens.]