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

Barksdale trillium, furrowed wakerobin, southern red trillium

Rhizomes

horizontal, brownish, thick, praemorse, fleshy.

horizontal–slightly erect, thick, praemorse.

Scapes

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

1–4+, round in cross section, 3–7 dm, 2–2.5 times as long as bract, stout, glabrous.

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).

subsessile;

blade obovate to broadly elliptic, 13–20 × 8–22 cm, not glossy, base attenuate, apex acuminate.

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.

facing outward at right angle to pedicel, above bracts, odor faintly musty, like fresh fungus;

perianth gaping, strongly 3-dimensional;

sepals spreading, usually streaked or entirely purplish maroon, occasionally entirely green except on margins, elliptic, 15–38 × 9–15 mm, margins entire, apex strongly sulcate-acuminate;

petals carried somewhat forward to recurved-spreading in distal 1/2, usually dark reddish maroon to purplish, rarely cream to soft yellow, pink, white, or 2-colored, heavy-veined, ovate to broadly ovate-overlapping, 1.8–5 × 1–3 cm, heavy-textured, apex acuminate, rarely somewhat sulcate;

stamens erect, ± equaling or slightly longer than ovary, 15–18 mm;

filaments purple to white, 3–5 mm, slender;

anthers straight, purplish to yellow, 5–12 mm, thick, dehiscence introrse;

connectives equaling or ± shorter than anther sacs;

ovary usually dark purple, globose to flask-shaped, 6-angled, 14–18 mm, broadly attached basally;

stigmas prominent, recurved, distinct, purple, not lobed adaxially, basally thickened, gradually tapered, 2–5 mm, fleshy;

pedicel usually stiffly erect (rarely almost horizontal above bracts), straight, reflexed ± 90° at tip, 6–11 cm.

Fruits

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

red, fragrance of fresh mushrooms, ± globose to pyramidal, 1.5–3 × 1.2–2.8 cm, juicy to pulpy.

2n

= 10.

= 10.

Trillium sessile

Trillium sulcatum

Phenology Flowering spring (Mar–early May). Flowering mid spring (Apr–May).
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 mesic woodlands, especially moist north- or east-facing slopes, wooded ledges and stream banks on neutral to slightly acid soil
Elevation 100–300 m (300–1000 ft) 300–400 m (1000–1300 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; NC; TN; VA; WV
[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 sulcatum is present mainly on the Cumberland Plateau and is absent from the Great Smoky Mountains and the southern Blue Ridge Mountains.

T. S. Patrick (1984) described Trillium sulcatum flowers as “relatively small and turned downward.” This is true of plants from the type locality; however, in most plants of the Cumberland Plateau, the flowers are quite large and flattened, and the petals are recurved distally and face outward.

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

Source FNA vol. 26, p. 115. FNA vol. 26, p. 104.
Parent taxa Liliaceae > Trillium > subg. Phyllantherum Liliaceae > Trillium > subg. Trillium
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. 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. sessile, T. simile, T. stamineum, T. underwoodii, T. undulatum, T. vaseyi, T. viride, T. viridescens
Name authority Linnaeus: Sp. Pl. 1: 340. (1753) T. S. Patrick: Brittonia 36: 27, figs. 1–4. (1984)
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