Sub-category: Carrot family
Endangered in Connecticut. Perennial plant is 1 to 3 feet tall, branching sparingly. The stems are round, hairless, and dull green to reddish brown. The larger leaves are doubly compound, while the smaller upper leaves may be singly compound. They are arranged alternately along the stems. In each compound leaf, the leaflets form groups of three (trifoliate). A lower compound leaf may be 12 inches long and 6 inches across, while the upper compound leaves are much smaller. There is a sheath at the base of each compound leaf. A typical leaflet is about 1 inch long and 0.5 inches across. It is dull green with a smooth surface and edges, and oval, ovate, or oblanceolate in shape. The terminal leaflet has a conspicuous petiole, while the side leaflets are usually sessile, or nearly so. Some of the upper stems terminate in compound umbels of tiny yellow flowers. When fully mature, a compound umbel will span about 4 to 7 inches and consist of about 12 to 15 umbellets. The umbellets will be widely spaced, giving the compound umbel and airy appearance. Each umbellet will consist of about 12 flowers. Each flower is less than 1/8 of an inch across and has 5 yellow petals. The blooming period occurs during late spring or early summer and lasts about one month. There is no noticeable floral scent. Each flower is eventually replaced by a 5-angled fruit.
Found in dry upland prairies, edges of hill prairies, upland savannas, rocky upland forests, bluffs, areas along woodland paths, eroded clay banks in semi-shaded areas, and thickets. This plant typically occurs at the edge of dry wooded areas, especially where slopes occur.