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

spotted trillium, spotted 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, 1.4–4 dm, slender to 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).

held well above ground, tips only touching ground in early anthesis, sessile;

blade dark green, mottling darker, mottled to varying degrees, mottling becoming obscure with age, broadly ovate-elliptic to elliptic, 7–15 × 4.6–6.7 cm, not glossy, apex rounded or barely 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 faintly spicy and bananalike;

sepals displayed above bracts, spreading almost to horizontal, often suffused or streaked with purple-maroon, lanceolate-linear, 22–50 × 5–7 mm, margins entire, apex rounded-acute, recurving slightly;

petals long-lasting, spreading-erect, ± connivent, ± concealing stamens and ovary or sometimes slightly spreading early, only partially obscuring stamens, becoming more erect and even touching in the manner of Trillium cuneatum when older, clear dark red-maroon, or reddish purple, without muddy or brown tones of many purple sessile species, or, rarely, purple basally and yellow toward apex, or clear sulfur yellow, not spirally twisted, narrowly oblanceolate-spatulate to linear-spatulate, widest above middle, narrowing to apex, 4–7 × 0.7–1.7 cm, thick-textured, margins entire, slightly involute in proximal 1/2, apex acute to round-acute;

stamens erect, 12–20 mm;

filaments dark purple, 2–3 mm, widest at base, much shorter than anther sacs;

anthers erect, straight, brownish purple, 10–16 mm, dehiscence introrse on broad connective;

connectives brown-purple, straight, essentially not extended beyond anther sacs;

ovary dark purple, ovoid, weakly 3-angled to smooth (rarely very obscurely 6-angled), angles often obscured in large, turgid ovary, 8–11 mm;

stigmas erect, divergent-recurved, distinct, purplish, subulate, 2–4 mm, fleshy.

Fruits

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

dark purplish green, odor not reported, ovoid, obscurely 3- to 6-angled, bearing persistent stigma, 1 × 2 cm, pulpy.

2n

= 10.

Trillium sessile

Trillium maculatum

Phenology Flowering spring (Mar–early May). Flowering mid winter–early spring (early Feb–early 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 mesic forests, particularly banks and bluffs of rivers, floodplains, often where quite brushy, rich soils, calcareous soils, alluvium
Elevation 100–300 m (300–1000 ft) 0–500 m (0–1600 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; FL; GA; SC
[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.)

In their account of the Carolinas flora, A. E. Radford et al. (1968) did not treat Trillium maculatum or give any explanation of why they omitted this species, which is fairly widely distributed in southeastern South Carolina and morphologically is one of the more distinct sessile trilliums.

Many color forms occur and have been named. In forma luteum J. D. Freeman, for example, all floral organs lack purple pigment, and the petals are clear, soft yellow, whereas forma simulans J. D. Freeman has yellow petals with purple bases, and purple stamens and carpels. These are illustrated in color in F. W. Case and R. B. Case (1997).

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

Source FNA vol. 26, p. 115. FNA vol. 26, p. 112.
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. 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: Med. Fl. 2: 103. (1830)
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