Perennial herb 20 cm - 0.9 m tall Stem: erect, grayish green, appearing as a stalk for the plant's single leaf. Flowers: borne five to 70 on a terminal inforescence 3 - 6 cm long, yellowish green or greenish purple, with three to four sepal-like bracts, six petal-like sepals 3 - 6 mm long and 2 - 3 mm wide, 0.1 - 0.7 mm styles, and six stamens. The petals are reduced to gland-like nectar-producing structures 1 - 2.5 mm long. Flowers open before leaves are fully expanded. Fruit: undeveloped because ovary is broken by the two developing seeds, exposing the short-stalked, naked seeds. The seeds are dark blue, 5 - 8 mm long, fleshy, and covered with a waxy whitish coating (glaucous). Leaflets: 5 - 8 cm long, 2 - 10 cm wide, oblong to inversely egg-shaped, two-to five-lobed near the tip, covered with a waxy whitish coating (glaucous) when young. Leaf: on a stalk dividing into three branches, with each branch dividing into three more branches and ending in three leaflets (triternate).
Similar species: Podophyllum peltatum lacks compound leaves, has a single drooping flower located between two leaves, and a yellow berry. Jeffersonia diphylla has leaves divided into two kidney-shaped segments, flowers borne solitary on a leafless stalk, and brownish capsule-like fruit .
Flowering: mid April to late May
Habitat and ecology: Locally common in mesic woods, most often growing on northeast-facing slopes.
Occurence in the Chicago region: native
Etymology: Caulophyllum comes from the Greek words kaulon, meaning stem, and phyllon, meaning leaf, suggesting that the stem appears to be a stalk for the highly branched compound leaf. Thalictroides refers to the resemblance of the leaves to Thalictrum.
Erect, 3-8 dm, glaucous when young; lfls obovate- oblong, 2-5-lobed above the middle, 5-8 cm at maturity; infl a small, panicle-like or raceme-like cyme, 3-6 cm; fls yellowish-green or greenish-purple, the slender, spreading, somewhat twisted sep 1 cm; seeds bitter, dark blue, 5-8 mm, on stalks nearly as long; 2n=16. Rich, moist woods; N.B. to Ont. and Man., s. to S.C., Ala., and Mo. Apr., May. Some authors recognize 2 largely sympatric vars. Var. thalictroides has variously yellow, purple or green sep mostly 4-5 mm. Var. giganteum Farw. blooms 2 weeks earlier and has fewer fls larger in all parts, the consistently purple sep 6-8 mm. (C. g.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.