[*] Ovary and fruit 6-angled and more or less winged.
[+] Flower sessile; the very broad connective produced beyond the anther-cells.
1. T. séssile, L. Leaves sessile, ovate or rhomboidal, acute, often blotched or spotted; sepals spreading; sessile petals erect-spreading, narrowly lanceolate or oblanceolate, dark and dull purple, varying to greenish, fruit globose, 6´´ long.—Moist woods, Penn. to Fla., west to Minn. and Ark.
2. T. recurvàtum, Beck. Leaves contracted at the base into a petiole, ovate, oblong, or obovate; sepals reflexed; petals pointed, the base narrowed into a claw, oblong-lanceolate to -ovate, dark purple; fruit ovate, strongly winged above, 9´´ long.—Rich woods, Ohio and Ind. to Minn. and Ark.
[+][+] Flower pedicelled; connective narrow, not produced; leaves subsessile.
[++] Pedicel longer than the flower; filament shorter than the anther.
3. T. eréctum, L. Leaves very broadly rhombic (2½–6´ wide), shortly acuminate; pedicel (1–3´ long) usually more or less inclined or declinate; petals ovate to lanceolate (9–18´´ long), brown-purple or often white or greenish or pinkish; stamens equalling or exceeding the stout distinct spreading or recurved stigmas; fruit ovate, 1´ long, reddish.—Rich woods, N. Scotia to N. C., west to Minn. and Mo. Flowers ill-scented.
4. T. grandiflòrum, Salisb. Leaves less broadly rhombic-ovate (1½–4´ wide); pedicel erect or ascending; petals oblanceolate, often broadly so (1½–2½´ long), white turning rose-color or marked with green; stamens with stout filaments (persistently green about the fruit) and anthers, exceeding the very slender erect or suberect and somewhat coherent stigmas; fruit globose, ½–1´ long.—Rich woods, Vt. to N. C., west to Minn. and Mo.
[++][++] Pedicel short, recurved or strongly declinate; filaments slender, about equalling the anther.
5. T. cérnuum, L. Leaves very broadly rhombic-ovate (2–4´ broad); petals white or pink, ovate- to oblong-lanceolate (6–12´´ long), wavy, recurved-spreading; stamens with short anthers, shorter than the stout recurved distinct stigmas; fruit ovate.—Moist woods, N. Eng. to Minn., south to Ga. and Mo.