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

green trillium, Ozark green trillium, Ozark trillium, tapertip wakerobin

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.

1–3, round in cross section, 2–5 dm, ± stout, glabrous to scabrous.

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).

touching ground in early anthesis or not at all, sessile;

blade dark green, obscurely marked with few–many darker blotches (very rarely unmottled), mottling becoming obscure with age, few or no stomates adaxially, ovate-elliptic to broadly so, 8.5–14 × 6.8–9 cm, 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.

erect, odor, if present, spicy or musty;

sepals displayed above bracts, widely spreading, green or variously purple marked, lanceolate, 38–60 × 5–12 mm, margins entire, apex acute;

petals long-lasting, erect, ± connivent, ± concealing stamens and ovary, purplish black on claw, greenish to yellow-green distally, sometimes all dark purple, occasionally slightly twisted, linear to narrowly spatulate, 4–8 × 0.8–1.2 cm, thick-textured, base slightly thickened and clawed, margins entire, apex rounded, lacking nipple;

stamens erect, connivent (clustered together, leaning upon each other), 16–25 mm;

filaments olive or purplish brown, 2.5–5 mm, very slender, widened basally;

anthers erect, straight or slightly incurved, olive-brown, 13–20 mm, ± slender, dehiscence latrorse;

connectives brownish, barely extending beyond anther sacs;

ovary pale greenish white basally, purplish distally, ovoid, 6-angled, 5.5–10 mm;

stigmas erect, divergent-recurved, distinct, purplish abaxially, sessile, almost linear, 6–10 mm, ± equaling ovary, ± not fleshy, very slightly widened basally.

Fruits

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

dark purplish green or green, odor unreported, ovoid, obscurely angled, with remains of persistent stigma, 0.7–1.5 cm, pulpy, not juicy at time of separation from receptacle.

2n

= 10.

Trillium sessile

Trillium viridescens

Phenology Flowering spring (Mar–early May). Flowering spring (early Apr–mid 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 Deciduous forests, usually quite rich, on banks, bluffs, talus slopes, floodplain alluvium, with cane (Arundinaria) or on sloping banks just above normal flood levels in heavy, clayey soils, with common spring ephemerals
Elevation 100–300 m (300–1000 ft) 100–400 m (300–1300 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
AR; KS; MO; OK; TX
[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.)

Of conservation concern.

J. D. Freeman (1975) considered that Trillium viridescens intergrades with T. gracile in northeastern Texas and stated that these putative intergrades produce purple petals, but purple-petaled forms also occur in Arkansas, far from the influence of T. gracile.

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

Source FNA vol. 26, p. 115. FNA vol. 26, p. 117.
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. 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. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride
Name authority Linnaeus: Sp. Pl. 1: 340. (1753) Nuttall: Trans. Amer. Philos. Soc., n. s. 5: 155. (1837)
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