Key from Flora of the Carolinas and Virginia 1a Leaves mottled with 2-3 different shades of green (vary rarely the mottling not apparent); flower sessile; [subgenus Phyllantherum] . . . . . . . . . . . . . . . . . .KEY A 1b Leaves solid green; flower on a pedicel (the pedicel sometimes very short or essentially absent in T. pusillum) [subgenus Trillium]. . . . . . . . . . . . . . . . . . . . . . .2 2a Petals relatively thick in texture, straight-margined, maroon or white, rarely yellow or green (if white, turning brown with age); stigmas thicker at base, tapering gradually toward tip, distinct; ovary purple-black, maroon, pink, or white, 6-angled; [Erectum group]. . . . . . . . . .KEY B 2b Petals relatively delicate in texture, wavy-margined, white to deep pink (if white, generally fading to pink with age); stigmas thin, uniform in thickness from base to apex, somewhat fused at the base into a short style' ovary greenish-white to white, 3- or 6-angled or -lobed [Grandiflorum group] . . . . . . . . . . . . . . . . . . . .KEY C KEY A trilliums with sessile flowers and mottled leaves (subgenus Phyllantherum) 1a Scape more-or-less decumbent in a gentle S-shape, the leaves ling on the ground, or nearly so; flower fragrance putrid; [T. sessile group] . . . . . . . . . . . . . . . . . . .2 1b Scape erect, straight, the leaves borne well above the ground (the leaf tips sometimes nearly touching the ground); flower fragrance various. . . . . . . . . . . . . . . .3 2a Anther dehiscence extrorse (towards the outside of the flower); stamens about 0.25x as long as the petals; upper stem puberulent; petals 4-10 cm long; filaments 2-5 mm long; [plants approaching our area in GA]. . . . . [T. decumbens] 2b Anther dehiscence introrse (towards the inside of the flower); stamens about 0.5x as long as the petals; upper stem glabrous; petals 2.5-5.5 cm long; filaments 1-2 mm long; [plants known in our area only in SC]. . . . . .T. reliquum 3a Sepals abruptly deflexed between and below the leaves, distinctly descending below a horizontal plane; filaments about as long as incurved anthers; [T. recurvatum group] . . . .4 3b Sepals erect, ascending or spreading, usually borne at or above a horizontal plant; filaments much shorter than the upright anthers . . . . . . . . . . . . . . . . . . . . . . . .5 4a Leaves sessile or subsessile, borne in a descending or drooping manner (similar to the sepals); petals usually more than 4X as long as wide . . . . . . . . . . . T. lancifolium 4b Leaves distinctly petiolate, borne in an ascending manner (strongly contrasting in position with the strongly deflexed sepals); petals usually ca. 2x as long as wideT. recurvatum 5a Petals spreading to horizontal with 1-2 spiral twists (looking something like an airplane propellor); anther dehiscence extrorse (towards the outside of the flower); [T. sessile group] . . . . . . . . . . . . . . . . . T. stamineum 5b Petals erect to slightly spreading, not spirally twisted; anther dehiscence introrse (towards the inside of the flower), or latrorse (towards the side). . . . . . . . . . . . .6 6a Petals broadly spatulate, clawed; petals pale lemon-yellow (the claws greenish or maroon); flower fragrance clove- like; [plants of the Savannah River drainage, from sw NC southeastwards along the GA-SC border]; [T. sessile group]T. discolor 6b Petals lanceolate, elliptic, obovate, or oblanceolate, but not broadly spatulate and distinctly clawed; petals maroon- red, purplish-brown, yellow or green; flower fragrance various; [plants collectively widespread in our area]. . . . . .7 7a Stigmas more than 1.5x as long as the ovary; stamens about 0.5x as long as the petals; anther connectives prominently prolonged into a beak 1.0-5.0 mm long (beyond the anther sacs); [T. sessile group]. . . . . . . . . . . . . . . T. sessile 7b Stigmas as long as the ovary or shorter; stamens less than 0.x as long as the petals; anthers blunt connectives extended less than 1.0 mm beyond the anther sacs . . . . . . . .8 8a Ovary ellipsoid; leaves acute, the margins of the outer 1/3 more or less straight; leaf blade mottled with 3 or more shades of green, the palest shade forming a very conspicuous pale green streak along the midvein [plants of the Coastal Plain and fall-line area of GA, AL, and FL panhandle]; [T. sessile group] . . . . . . . . . . . . . . . . .9 8b Ovary ovoid; leaves acute to acuminate, the margins of the outer 1/3 convex; leaf blade mottled with 2-3 shades of green, paler shades sometimes prominent along the midvein, but not as above; [plants collectively widespread in our area]; [T. maculatum group] . . . . . . . . . . . . . . . . . 10 9a Stem 2.5-3x as long as the leaves; petals oblanceolate- obovate, usually 1.5-3x as long as wide. . . . . . . T. decipiens 9b Stem 1.2x as long as the laves; petals narrowly elliptic to oblanceolate-obovate, usually 3-5x as long as wide T. underwoodii 10a Ovary 3-angled at base of stigmas rarely hexagonal); petals narrowly spatulate (appearing clawed), mostly less than 4x as long as wide; stamens uniform, anther dehiscence introrse or lateral. . . . . . . . . . . . . . . . . T. maculatum 10b Ovary hexagonal or 6-ridged at base of stigmas; petals elliptic-oblanceolate to oblanceolate, mostly less than 4x as long as wide; stamens uniform, anther dehiscence introrse or lateral . . . . . . . . . . . . . . . . . . . . . 11 11a Flower fragrance fruity-spicy, like green apples or Calycanthus (rarely musky); petals maroon, bronze, green. yellow; portions of ovary and stamens purplish during anthesis . . . . . . . . . . . . . . . . . . . . . . .T. cuneatum 11b Flower fragrance lemon-like; petals greenish-yellow darkening to yellow; ovary and stamens greenish-white during anthesis . . . . . . . . . . . . . . . . . . . .T. luteum KEY B trilliums with unmottled leave and pedicellate flowers of the Erectum group 1a Pedicel abruptly declined below the leaves; leaves petiolate to subsessile (or even sessile); petals recurved between the sepals . . . . . . . . . . . . . . . . . . . . . . .2 1b Pedicel inclined, erect or declined (the flower generally borne above the leaves); leaves sessile to subsessile; petals variously disposed, generally spreading in the same plane as the sepals or forming a cup concealing the ovary in side view (then, recurved toward the apex) . . . . . . . . .4 2a Stamens far exceeding the pistil, filaments as long as the ovary or longer, at least partly maroon, the anther sacs yellow to maroon; ovary small, globose, 3-12 mm long; flower fragrance pungent, rose-like; pedicel long, 3-13 cm long; petals strongly overlapping, usually maroon (rarely white or whitish) . . . . . . . . . . . . . . . . . . .T. vaseyi 2b Stamens at most 1.5x longer than the pistil, filaments shorter than the ovary, white, the anther sacs lavender to vivid purple (or albino); ovary large, ovoid, 1017 mm long; flower fragrance weak, like green apples; pedicel short, 1.5-3 cm long; petals not strongly overlapping, usually white (rarely maroon) . . . . . . . . . . . . . . . . . . . . .3 3a Anthers 7.5 mm long or less, about as long as the filaments or shorter; petals narrowly elliptic to obovate, often scarcely larger than the sepals delicate, occasionally margined in pink or green; [plants of damp forests south to n. VA] . . . . . . . . . . . . . . . . . . . . . . . . T. cernuum 3b Anthers 7.0 mm long or more, longer than the filaments; petals ovate to elliptic, much broader than the sepals; [plans of mesic forests north to n. NC]. . . . . . . . T. rugelii 4a Anthers creamy-white, 2-5x as long as the filaments; ovary white to pink (rarely darker), ovoid (widest near the base); stigmas prominent, nearly as long as the ovary; flower fragrance weakly sweet to musty . . . . . . . .T. flexipes 4b Anthers creamy-white, yellowish, or purplish, at most 2.2x as long as the filaments; ovary purple-black to maroon (or albino), subglobose; stigmas smaller, less than 0.3x as long as the ovary; flower fragrance variable (see below) . . . .5 5a Petals lanceolate to narrowly ovate or elliptic, spreading from base in the same plane as the sepals, rarely more than 2x as broad as the sepals; sepals 0.5-0.8x as long as he pedicel, weakly sulcate-tipped (keeled and upturned near apex); flower fragrance unpleasant, musty . . . . . . T. erectum 5b Petals ovate, overlapping in some instances and forming a cup-shaped base, variably recurved apically, more than 2x as broad as the sepals; sepals less than 0.5 as long as the pedicel, sulcate-tipped; fragrance pleasant, sweet to fungal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 6a Sepals 0.4-0.7x as long as the pedicel; leaves broadly elliptic; stamens 1.2-1.8x pistil height; flowers generally large, petals much longer than the sepals; sepals green; petals usually white (rarely maroon); flower fragrance sweet, like green apples; [plans of sw NC and nw SC in our area]. . . . . . . . . . . . . . . . . . . . . . . . . .T. simile 6b Sepals 0.2-0.4x as long as the pedicel; leaves broadly obovate; stamens 0.9-1.6x pistil height; flowers relatively small, petals only slightly longer than the sepals; sepals suffused with purple; petals usually maroon (rarely white); flower fragrance fungal, like fresh mushrooms; [plants of sw VA and nw NC in our area] . . . . . . . . . . . . .T. sulcatum KEY C trilliums with unmottled leaves and pedicellate flowers of various affinities [the Grandiflorum group] 1a Petals white with triangular red blaze (rarely entirely white or pinkish); anther sacs lavender to white, dehiscence extrorse; fruit a red berry; leaves long- acuminate; [plants of acidic sites in the mountains, generally strongly associated with either Pinus, Tsuga, Picea, Rhododendron, or other heaths] . . . . . . . T. undulatum 1b Petals white to deep pink, lacking a red blaze; anther sacs yellow, dehiscence introrse; fruit a white to greenish- white, fleshy, irregularly dehiscent capsule; leaves obtuse to acute (or somewhat acuminate in T. grandiflorum); [plants of less distinctly acidic sites collectively widespread in our area] . . . . . . . . . . . . . . . . . . . .2 2a Pedicel declined below the leaves (rarely erect); sepals arcuate-recurved; anthers irregularly twisted outward; pollen egg-yolk yellow . . . . . . . . . . . . . . . T. catesbaei 2b Pedicel inclined above leaves to strictly erect; sepals not arcuate-recurved; anthers erect, regular; pollen light yellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 3a Sepals about as broad as the petals or broader, obtuse; leaves obtuse; anthers purplish-green between anther sacs; pedicel erect through fruiting . . . . . . . . . . . . . . . . .4 3b Sepals narrower than the petals, acute; anthers white to greenish-white between the anther sacs; leaves obtuse, cute, or acuminate; pedicel somewhat angled from the vertical . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 4a Pedicel 1-4 mm long . . . . . . T. pusillum var. virginianum 4b Pedicel 5-30 mm long . . . . . . .T. pusillum var. pusillum 5a Ovary obscurely 3-lobed; leaves less than 5 cm long, blue- green, obtuse. . . . . . . . . . . . . . . . . . . . . .T. nivale 5b Ovary sharply 6-angled (-winged); leaves more than 5 cm long, green, acute to acuminate . . . . . . . . . . . . . . . .6 6a Petals obovate, tightly rolled at base, abruptly flared near the apex; leaves broadly elliptic, acuminate; style minute, less than 1.0 mm long . . . . . . . . . .T. grandiflorum 6b Petals elliptic, loose, gradually separating; laves ovate, acute; style conspicuous, more than 1.5 mm long . . T persistens