Perennial herb with a short, stout rhizome stem 8 - 15 cm tall Flowers: single, upright, with six distinct tepals. Flower stalk more or less upright, 1 - 3 cm long, recurved in fruit. Stamens six, alternating in two whorls of three. Sepals: three, persistent, bluish green, 1 - 3.2 cm long, 2 - 7 mm wide, much shorter than the petals, lance-shaped, spreading, flat. Petals: three, white (sometimes with a pinkish base), 1.5 - 4 cm long, 0.8 - 1.5 cm wide, egg-shaped to oblong, recurved to upright-spreading, shriveling after the flowering period. Fruit: a many-seeded berry, greenish white, 0.6 - 1 cm long, 0.5 - 0.8 cm wide, rounded to egg-shaped, pulpy. Seeds many, elliptic.
Similar species: This species and Trillium recurvatum differ from other Trillium species by having distinctly stalked leaves. Trillium recurvatum differs by having a stalkless flower that is typically maroon.
Flowering: mid-March to late April
Habitat and ecology: Rare in the Chicago Region. Typical of 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. Nivale means snow-white.
Diminutive; stem 8-15 cm at anthesis; lvs elliptic to lance- ovate or ovate, at anthesis 3-5 cm, acute or usually obtuse, rounded at base to a petiole 5-10 mm; peduncle ±erect, 1-3 cm, recurved in fr; sep lanceolate, much shorter than the pet; pet white (sometimes pinkish at base), elliptic or elliptic-obovate, 2.5-4 cm, obtuse; anthers 7-10 mm, somewhat exceeding the slender filaments; ovary subglobose, roundly 3-lobed. Rich moist woods; w. Pa. and W.Va. to Minn., s. S.D., w. Nebr., and Mo. Mar., Apr.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.