Perennial herb with a short, stout rhizome stem 10 - 30 cm tall Flowers: single, upright, stalkless, with six distinct tepals, bad-smelling. Stamens six, alternating in two whorls of three. Sepals: three, persistent, streaked with maroon, 9 mm - 3.5 cm long, 4 - 8 mm wide, more or less equal to the petals, lance- to egg-shaped, spreading or ascending. Petals: three, maroon (sometimes green to yellow), 1.7 - 3.5 cm long, 0.7 - 2 cm wide, narrowly to broadly elliptic with a tapering base, ascending, more or less concealing the stamens and ovary, long-lasting. Fruit: a many-seeded berry, dark greenish purple, nearly spherical, six-angled (somewhat wing-like), pulpy. Seeds many, elliptic.
Similar species: This Trillium species is easily distinguished from the others by having stalkless leaves and a stalkless flower.
Flowering: mid-April to mid-May
Habitat and ecology: Rare in the Chicago Region, found in rich moist woods.
Occurence in the Chicago region: native
Notes: Trilliums do not actually have true leaves or stems above the ground. The underground rhizome produces scale-like leaves called cataphylls. The aboveground leaf-like structures are bracts that subtend the flower, but these are internally and externally similar to leaves and function in photosynthesis. Many authors will refer to them as leaves.
Etymology: Trillium comes from the Greek word trilix, meaning triple, referring to how all the plant parts occur in threes. Sessile means stalkless.
Rhizome very thick and stout; stem 1-3 dm at anthesis; lvs broadly ovate to rotund, sessile, rounded, broadly obtuse or obscurely cuspidate, usually only inconspicuously or not at all mottled, seldom over 9 cm at anthesis; fl sessile, foetid; sep spreading or ascending, lance-ovate, 2-3 cm; pet normally maroon (yellow or green), ascending, narrowly to broadly elliptic, narrowed to a sessile base, equaling or slightly longer than the sep and twice as long as the stamens; filaments (2-)3-4(-5) mm, less than half as long as the introrse anthers, the flattened connective with a prolongation nearly as long as the filament; stigmas 1.5-2 times as long as the subglobose, sharply 6-angled or -winged ovary; 2n=10. Rich moist woods; w. Pa. and sw. N.Y. to s. Mich., Ill., Mo., and e. Kans., s. to Md., Va., n. N.C., n. Ala., and n. Ark. Apr., May.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.