The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

sessile trillium, sessile-flower wake-robin, toad trillium, toadshade

bloody butcher, cuneate trillium, large toadshade, little sweet betsy, purple toadshade, sweet betsy, whip-poor-will flower

Rhizomes

horizontal, brownish, thick, praemorse, fleshy.

horizontal, brownish, short, thick, praemorse, not brittle.

Scapes

1–3, round in cross section, 0.8–2.5 dm, slender to stout, glabrous.

1–5, 1.6–4.5 dm, smooth to rough near bract attachment.

Bracts

held well above ground, sessile;

blade green to bluish green, strongly to sparsely mottled, mottling becoming obscure with age, oval to suborbicular, 4–10 × 2–8 cm, base broadly attached, apex rounded-acuminate to bluntly parallel sided-acuminate (rounded basally to its broad attachment).

held well above ground, sessile;

blade green to purplish green, weakly to strongly mottled, mottling becoming obscure with age, ovate, ovate-elliptic, occasionally ovate-orbicular with margins overlapping, 7–18.5 × 7–13 cm, usually widest below middle, not glossy, base ± rounded, margins of distal 1/3 convex-curved to apex, apex acuminate to acute.

Flower

erect, odor pungent, spicy;

sepals displayed above bracts, spreading, green, variously streaked with maroon, lanceolate-oblanceolate, 9–35 × 4–8 mm, margins entire, apex rounded-acuminate;

petals long-lasting, erect, ± connivent, ± concealing stamens and ovary, maroon, brownish maroon, green, or yellowish green, not spirally twisted, oblanceolate to elliptic, occasionally almost orbicular, 1.7–3.5 × 0.7–2 cm, thick-textured, narrowed near basal attachment (but not truly clawed), margins entire, apex gradually rounded-tapered to acute;

stamens straight, 10–23 mm;

filaments red-purple, 2–5 mm, dilated basally;

anthers erect, straight, gray-purple, 9–16 mm, thick, dehiscence introrse;

connectives purplish brown, straight, projecting 2–5+ mm beyond anther sacs;

ovary greenish white basally, purple distally, ovoid to globose, 6-angled, pyramidally narrowed to stigmas, 4–8.5 mm;

stigmas erect, divergent-recurved, distinct, purple, subulate, 1–5 mm, ± fleshy.

borne upon bracts, erect, odor usually pleasant, faint, spicy, reminiscent of odor of bruised sweetshrub (Calycanthus) leaves, occasionally musty or unpleasant;

sepals widely spreading, variably green, purple-streaked to all purple, oblong-lanceolate, 27–60 × 7–13 mm, margins entire, apex rounded to acute;

petals long-lasting, erect, ± connivent, ± concealing stamens and ovary, maroon, maroon-purple, brownish purple, bronze, greenish purple, clear green, yellowish green, pale lemon yellow, or 2-colored, yellow distally with purple base, in occasional clones, flowers open or quickly fade to bright copper bronze, the particular color pattern is consistent from year to year, fading to browner tones with age except in yellow or green forms, not spirally twisted, shape quite variable across range, elliptic-obovate to oblanceolate, 4–7 × 0.9–2.7 cm, thick-textured, with widest portion at or above middle, narrowed to usually cuneate basally, not clawed, margins flat, entire, apex acute, rounded-acute to obtuse;

stamens erect, straight, brownish purple-green, 11–18 mm;

filaments brownish purple, 1.5–3.5 mm, widest at base;

anthers erect, straight, brownish gray, 7–14 mm, dehiscence latrorse or occasionally introrse;

connectives straight, scarcely (0.5 mm or less) if at all extended beyond anther sacs;

ovary maroon, ovoid to vase-shaped, weakly 6-angled or -ridged when mature, 12–15 mm;

stigmas erect, slightly diverging to spreading, distinct, purplish gray, linear-subulate to thickly subulate, 4–15 mm, fleshy.

Fruits

baccate, dark greenish purple, odorless, subglobose, 6-angled, angles somewhat winglike, pulpy, not juicy.

green or with purple streaks, ovoid, very obscurely angled or angles no longer apparent, 2 × 1–1.5 cm, mealy or pulpy, fleshy, not juicy.

2n

= 10.

= 10.

Trillium sessile

Trillium cuneatum

Phenology Flowering spring (Mar–early May). Flower late winter–mid spring (early Mar–mid Apr).
Habitat Rich woodlands, limestone districts, calcareous soils, floodplains, riverbanks, clayey alluvium, less fertile soils, high, dry limestone woods, persists under light pasturing, in fencerows and brushy areas after lumbering Rich, mostly upland woods, especially limestone soils, also less calcareous sites, occasionally found in old fields, ditches, or coal-mine tailings
Elevation 100–300 m (300–1000 ft) 50–400 m (200–1300 ft)
Distribution
from FNA
AL; AR; IL; IN; KS; KY; MD; MI; MO; NC; NY; OH; OK; PA; TN; VA; WV
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; GA; KY; MS; NC; SC; TN
[WildflowerSearch map]
[BONAP county map]
Discussion

Trillium sessile is rather uniform throughout its range, with few color forms.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Trillium cuneatum has escaped locally and become established in Michigan and other states. It is most frequent on the Ordovician limestone-derived soils of southern Kentucky and Tennessee, and is perhaps the most vigorous and certainly the largest of the eastern sessile trilliums. Numerous, mostly unnamed color forms occur. Plants from the lower piedmont of Georgia, Alabama, and Mississippi, considered by most botanists to be of this species, have smaller, narrower petals than specimens from northeastern Alabama northward to Kentucky, and they are therefore sometimes difficult to place with certainty.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 26, p. 115. FNA vol. 26, p. 108.
Parent taxa Liliaceae > Trillium > subg. Phyllantherum Liliaceae > Trillium > subg. Phyllantherum
Sibling taxa
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, T. chloropetalum, T. cuneatum, T. decipiens, T. decumbens, T. discolor, T. erectum, T. flexipes, T. foetidissimum, T. gracile, T. grandiflorum, T. kurabayashii, T. lancifolium, T. ludovicianum, T. luteum, T. maculatum, T. nivale, T. ovatum, T. parviflorum, T. persistens, T. petiolatum, T. pusillum, T. recurvatum, T. reliquum, T. rivale, T. rugelii, T. simile, T. stamineum, T. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride, T. viridescens
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, T. chloropetalum, T. decipiens, T. decumbens, T. discolor, T. erectum, T. flexipes, T. foetidissimum, T. gracile, T. grandiflorum, T. kurabayashii, T. lancifolium, T. ludovicianum, T. luteum, T. maculatum, T. nivale, T. ovatum, T. parviflorum, T. persistens, T. petiolatum, T. pusillum, T. recurvatum, T. reliquum, T. rivale, T. rugelii, T. sessile, T. simile, T. stamineum, T. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride, T. viridescens
Name authority Linnaeus: Sp. Pl. 1: 340. (1753) Rafinesque: Autik. Bot., 133. (1840)
Web links