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

bent trillium, declined trillium, drooping trillium, nodding wakerobin

Rhizomes

horizontal, brownish, thick, praemorse, fleshy.

somewhat erect, thick, praemorse.

Scapes

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

1–several from single rhizome, round in cross section, 2–5 dm, 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).

sessile;

blade medium green without red or maroon undertones, rhombic, 7–25 × 7–25 cm, frequently wider than long, base attenuate from just above middle, 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.

flexed ca. 90° on summit of pedicel to face outward rather than upward, or variously carried on strongly declined pedicels;

sepals weakly recurved, green, lanceolate, 14–45 mm, shorter than or barely equaling petals, margins entire, apex acuminate;

petals flat or recurved in distal 1/2, creamy white, not 2-colored, veins conspicuously engraved, ovate-lanceolate to broadly ovate, 2–5 × 1–4 cm, texture heavy, margins entire, apex acute;

stamens large, ± erect, 9–23 mm;

filaments white, less than 1/2 anther length, thin;

anthers straight or very slightly recurving, creamy white or yellow, 5–18 mm, thick, dehiscence ± introrse;

ovary white, ovoid to flask-shaped, strongly 6-angled, 5–16 × 4–12 mm, widely attached basally;

stigmas recurved, distinct but closely grouped, white, not lobed adaxially, linear-subulate, short, thick, 4–13 mm, ± equaling ovary, fleshy;

pedicel stiffly erect, carried horizontally, or declined beneath bracts, rarely recurved, 4–12 cm.

Fruits

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

baccate, rosy red to purplish, fragrant of ripe fruit, ovoid to somewhat pyramidal at summit, strongly angled, 2–3.5 × 1–3 cm, very juicy at maturity.

2n

= 10.

= 10.

Trillium sessile

Trillium flexipes

Phenology Flowering spring (Mar–early May). Flowering spring (Apr–early Jun).
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 wooded slopes, floodplains in deciduous forests, especially over limestone
Elevation 100–300 m (300–1000 ft) 100–600 m (300–2000 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; DE; IA; IL; IN; KY; MI; MN; MO; NY; OH; PA; SD; TN; VA; WI; WV; ON
[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.)

Although there are no named varieties of Trillium flexipes, many forms exist and at least one has been named, forma walpolei (Farwell) Fernald. F. W. Case and G. L. Burrows (1962) mapped the occurrence of forma walpolei for Michigan and found it to occur only along the contact zone between T. flexipes and T. erectum. F. W. Case and R. B. Case (1993) crossed typical T. erectum and T. flexipes to produce identical color variations as occur in these wild, mixed-species populations. I consider this form to be a hybrid expression. Some of the hybrids have petals colored proximally and white distally, superficially resembling T. undulatum. Dried specimens, when hastily examined, resemble T. undulatum superficially and probably account for reports of that species from locations near Ann Arbor, Michigan, and various places in Indiana and Illinois, all of which are well out of the range of T. undulatum.

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

Source FNA vol. 26, p. 115. FNA vol. 26, p. 99.
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. 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
Synonyms T. declinatum, T. gleasonii
Name authority Linnaeus: Sp. Pl. 1: 340. (1753) Rafinesque: Autik. Bot., 133. (1840)
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