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giant purple wakerobin, giant trillium, giant wakerobin, sessile trillium, small-flower trillium

great white trillium, large-flower trillium, trille grandiflore, white trillium, white wake-robin

Rhizomes

± erect, brownish, somewhat compressed-thickened, superficially bulblike, praemorse, not brittle.

short, thick, praemorse.

Scapes

1–3, green, round in cross section, 2–6.5 dm, robust.

(1–)2–3(–many), round in cross section, 1.5–3+ dm, thick, glabrous.

Bracts

held well above ground, sessile (narrowing of bract blade may give bract subsessile appearance);

blade densely to weakly mottled in dark brownish green, mottling becoming more obscure to absent as bract matures, broadly ovate, 7–17.6 × 7.4–17.7 cm, not glossy, apex obtuse-rounded.

sessile or subsessile (occasionally weakly cuneate basally);

blade dark green with maroon overtones early, ovate-rhombic, 12–20 × 8–15 cm, apex acuminate.

Flower

erect, odor roselike, spicy;

sepals spreading-ascending above bracts, green, lanceolate, 35–65 × 7–12 mm, margins entire, flat, apex obtusely rounded;

petals long-lasting, erect, connivent, ± concealing stamens and ovary, yellow, bronze, maroon, brown, deep purple, reddish brown, pink, dark purplish red, purplish bronze, rarely greenish white, not spirally twisted, veins not engraved, oblanceolate to obovate, 6.5–10 × 1.5–2.5 cm, thick-textured, base cuneate, margins entire, apex variably acute to almost truncate, erose;

stamens erect, purplish, 17–26 mm;

filaments purple, ca. 4 mm, widest at base, much shorter than anther sacs;

anthers erect, straight, ± purple-brown, 13–22 mm, dehiscence introrse;

connectives purple, straight, extended ca. 1–1.5 mm beyond anther sacs;

ovary purple, ovoid, 6-angled, 6–12 mm;

stigmas small, divergent or erect, distinct, purple, subulate, 4–8 mm, not fleshy.

outfacing, erect, odorless;

sepals spreading, flat, green, very rarely streaked with maroon-purple, lanceolate, 20–55 × 12–23 mm, margins entire, apex acuminate or acute;

petals erect basally, recurving somewhat above middle to produce strongly funnelform corolla, obscuring ovary and base of style, white or rarely pink, without V-shaped or other markings, fading to dull pinkish purple, veins of adaxial surface conspicuous but not appearing engraved, shape variable, lanceolate to oblong, obovate, or, rarely, suborbicular, sides often parallel, 4–7.5 × 2–4 cm, thin-textured, base abruptly attenuate, margins overlapping basally, rolled, undulate-wavy in distal 1/2, apex ± acuminate;

stamens straight or barely recurved, 9–27 mm;

filaments white, much shorter than anthers, relatively thin;

anthers recurving slightly, pale yellow, strongly yellow when pollen exposed, long, 5–16 mm, slender, dehiscence introrse;

ovary inconspicuous, pale green or white, ovoid, 6-angled, 8–18 mm, basal attachment narrower than ovary width;

style barely united for 0.5–2 mm or merely closely grouped and separate;

stigmas erect, becoming spreading, weakly connate basally, pale green-white, uniformly linear, 3–18 mm, equaling or exceeding ovary, slender;

pedicel erect-ascending to strongly erect, 2–8+ cm.

Fruits

red-purple, fragrance not reported, ovoid, obscurely 6-angled, 2.5–3 cm, pulpy, juicy.

pale green, odorless, ± globose, obscurely 6-angled, 1.2–1.6 × 0.8–1.4 cm, mealy, moist (not juicy).

2n

= 10.

= 10.

Trillium chloropetalum

Trillium grandiflorum

Phenology Late spring–early summer (Apr–Jun).
Habitat Rich deciduous or mixed coniferous-deciduous upland woods, floodplains, roadsides
Elevation 20–700 m (100–2300 ft)
Distribution
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
from FNA
CT; DE; GA; IA; IL; IN; KY; MA; MD; ME; MI; MN; NC; NH; NJ; NY; OH; PA; SC; TN; VA; VT; WI; WV; NS; ON; QC
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

J. D. Freeman (1975) considered that Trillium chloropetalum differs from T. albidum in having introrse (not latrorse) anther sacs, and that the purple pigments present on anther and ovary tissue here are absent in T. albidum. In some places, hybridization between the two certainly has occurred, and a complete range of intergrades exists.

This species merits further study. The following varieties are only weakly differentiated and perhaps ought to be dropped.

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

Most variants of Trillium grandiflorum have green stripes or markings on the petals, many with numerous (4–30+) extra petals and/or bracts, and, often, much-deformed, monstrous characteristics. G. R. Hooper et al. (1971) showed that mycoplasmic organisms were present in all such forms examined, and were absent from normal plants. Most such forms should not be named taxonomically but, unfortunately, many have been. Nearly all of those that I examined represented stages in the development of the mycoplasma infection. Trillium grandiflorum, unlike most trilliums, produces many-petaled “double” forms. Forma roseum Farwell, opening a striking clear salmon-pink, occurs very rarely throughout the range, but is frequent in mixed or pure colonies along the Blue Ridge Mountains of Virginia.

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

Key
1. Petal tissue always with yellow pigments, often present with other pigments; petals yellow, greenish yellow, greenish purple, or bronze-green or brown.
var. chloropetalum
1. Petal tissue lacking yellow pigments; petals purple, reddish purple, garnet red, pink, or greenish white.
var. giganteum
Source FNA vol. 26. FNA vol. 26.
Parent taxa Liliaceae > Trillium > subg. Phyllantherum Liliaceae > Trillium > subg. Trillium
Sibling taxa
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, 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. erectum, T. flexipes, T. foetidissimum, T. gracile, 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. chloropetalum var. chloropetalum, T. chloropetalum var. giganteum
Synonyms T. sessile var. chloropetalum, T. giganteum var. chloropetalum T. rhomboideum var. grandiflorum, T. erythrocarpum
Name authority (Torrey) Howell: Fl. N.W. Amer., 661. (1902) (Michaux) Salisbury: Parad. Lond. 1: plate 1. (1805)
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