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

Idaho trillium, long-petioled trillium, petioled wakerobin, purple trillium, purple wakerobin, round-leaf trillium

Rhizomes

short, thick, praemorse.

± erect, often very deep, praemorse.

Scapes

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

typically 1, vertical but mostly subterranean, round in cross section, 0.4–1.7 dm, robust, glabrous.

Bracts

sessile or subsessile (occasionally weakly cuneate basally);

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

just at or slightly above soil, long-petiolate;

blade medium green, not mottled, ovate to elliptic, 7–14 × 5.5–10.2 cm, not glossy, apex obtuse or rounded;

petiole arising from scape apex at or near ground surface, 5–12 cm;

bract and petiole strongly resembling leaves of Plantago.

Flower

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.

in axil of bracts at or near ground level, ± erect, odor unknown;

sepals erect to widely spreading, often weakly recurved near middle, green, oblong-elliptic to oblanceolate, 22–47 × 7–10 mm, margins entire, apex acute;

petals long-lasting, ± connivent, ± concealing stamens and ovary, or erect-spreading early then ± connivent, erect to incurved, light maroon-red, purple, or greenish to yellowish, not spirally twisted, flat, linear-lanceolate, 3–5.5 × 0.4–1 cm, thick-textured, margins entire, apex acute;

stamens erect, (15–) 22–30 mm;

filaments olive, (3–)5–7 mm, slender;

anthers straight, brown or olive, 16–20 mm, slender, dehiscence latrose;

connectives yellow or orange, ± not extending beyond anther sacs;

ovary white, greenish, purplish distally, ovoid, sharply angled, 4–9 mm;

stigmas erect, divergent, distinct, purple or olive, linear-subulate, 7–20 mm, apex somewhat recurved.

Fruits

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

fragrance not reported, ovoid, strongly angled/winged, ca. 1 cm, pulpy, moist.

2n

= 10.

= 10.

Trillium grandiflorum

Trillium petiolatum

Phenology Late spring–early summer (Apr–Jun). Flowering spring (early Apr–late May).
Habitat Rich deciduous or mixed coniferous-deciduous upland woods, floodplains, roadsides Lower rocky hillsides just above stream flats, under brush, edges of coniferous and deciduous forests, open grassy glades, river-flats, wet, seasonally swampy ground and edges of sloughs
Elevation 20–700 m (100–2300 ft) 400–1400 m (1300–4600 ft)
Distribution
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]
from FNA
ID; OR; WA
[WildflowerSearch map]
[BONAP county map]
Discussion

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.)

Source FNA vol. 26. FNA vol. 26, p. 113.
Parent taxa Liliaceae > Trillium > subg. Trillium 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. 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. grandiflorum, T. kurabayashii, T. lancifolium, T. ludovicianum, T. luteum, T. maculatum, T. nivale, T. ovatum, T. parviflorum, T. persistens, 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. rhomboideum var. grandiflorum, T. erythrocarpum
Name authority (Michaux) Salisbury: Parad. Lond. 1: plate 1. (1805) Pursh: Fl. Amer. Sept. 1: 244. (1814)
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