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giant trillium, giant white wakerobin, sessile trillium, smallflower trillium, white toadshade

birthwort, red trillium, red wakerobin, stinking Benjamin, stinking willie, wake-robin

Rhizomes

horizontal, ± erect, brown, superficially bulblike, short, thick, not brittle.

short, thick, praemorse.

Scapes

often several from same rhizome terminus, round in cross section, 2.2–5.8 dm, stout.

1–2, often with numerous offsets forming heavy clumps, round in cross section, 1.5–6 dm, ± robust, glabrous.

Bracts

held well above ground, sessile;

blade weakly mottled with scattered, darker green spots, mottling often fading later in season, broadly ovate, 10–20 × 12–15 cm, not glossy, base rounded, apex obtuse.

sessile;

blade bright green, lacking dark pigmentation, major veins prominent, broadly rhombic to ovate-rhombic, 5–20 × 5–20 cm, about as broad as long, widest near middle, base attenuate, apex acuminate.

Flower

borne directly upon bracts, erect, fragrance roselike;

sepals conspicuous, spreading, displayed above bracts, pale green, lanceolate, 30–65 × 12–15 mm, margins entire, apex acute;

petals long-lasting, usually erect or slightly spreading, ± connivent, ± concealing stamens and ovary basally, white to creamy white, rarely soft pinkish rose near base, veins prominent but not engraved, not spirally twisted, obovate, more lanceolate in young plants, 4.8–8 × 2.2–3 cm, widest at or just above middle, ± thick-textured, base cuneate, margins entire, ± flat, apex rounded to acute;

stamens erect, greenish white, 15–25 mm;

filaments whitish green, 3–4 mm, slender;

anthers erect, straight, yellow, 11–20 mm, dehiscence latrorse;

connectives straight, extended ca. 1 mm beyond anther sacs, rounded;

ovary green or occasionally purple, ovoid, rounded 6-gonal, 6–11 mm;

stigmas erect to spreading, distinct, sessile, subulate, 4–7 mm, thin distally.

erect, ascending, or proximal to but above bracts, odor fetid, like a wet dog;

perianth open, flat;

sepals flat to sulcate apically, green, often streaked or overlain with maroon, occasionally entirely dark maroon, lanceolate-acuminate, 10–50 mm, equaling petals, ± 1/2 petal width, texture leafy, margins entire, apex acuminate;

petals spreading, carried in same plane as sepals or ascending slightly, dark reddish brown, maroon, purple, or white, sometimes pale yellow, major adaxial veins prominent and appearing somewhat engraved, usually flat, lanceolate, ovate-lanceolate, or occasionally ovate, 1.5–5 × 1–3 cm, 2 times sepal width, widest near base, heavy-textured, apex acuminate;

stamens erect to slightly recurved, 5–15 mm;

filaments white, pinkish, or dark purple, ± equaling anthers, but variable within local populations, thin;

anthers erect or weakly recurving, dark maroon, grayish maroon, or yellowish, strongly yellow when pollen exposed, 5–12 mm, dehiscence introrse;

ovary dark purple to maroon, even in white-flowered forms, ovoid, elliptic to globose, 6-angled, angles forming very low ridges when fruit is ripe, 5–10 mm, broadly attached at base;

stigmas recurved, distinct, dark purple, not lobed adaxially, subulate, short, 3–7 mm, ca. 1/2 or less length of ovary at anthesis, fleshy;

pedicel straight, erect, or somewhat declined but not strongly recurved below bracts, 1–10+ cm.

Fruits

green or purplish green, fragrance unknown, ovoid to globose, pulpy, juicy.

dark maroon, weakly fragrant of fruit, ± globose to slightly pyramidal, 1–1.6 × 1–1.5 cm, juicy.

2n

= 10.

Trillium albidum

Trillium erectum

Phenology Flowering spring (mid Mar–late Apr).
Habitat Moist slopes in rich mixed deciduous-coniferous forests or coniferous stands, brushy thickets on flats, open fields, pastures, and fencerows, dense second-growth coniferous forests, floodplains along streams and larger rivers
Elevation 100–200 m (300–700 ft)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from USDA
e North America
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

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

Key
1. Petals usually red, maroon, or dark purple.
var. erectum
1. Petals white.
var. album
Source FNA vol. 26, p. 106. FNA vol. 26, p. 98.
Parent taxa Liliaceae > Trillium > subg. Phyllantherum Liliaceae > Trillium > subg. Trillium
Sibling taxa
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, T. viridescens
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, T. chloropetalum, T. cuneatum, T. decipiens, T. decumbens, T. discolor, 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
Subordinate taxa
T. erectum var. album, T. erectum var. erectum
Name authority J. D. Freeman: Brittonia 27: 48, fig. 11. (1975) Linnaeus: Sp. Pl. 1: 340. (1753)
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