Trillium underwoodii
Trillium grandiflorum
longbract wakerobin, Underwood's trillium
great white trillium, large-flower trillium, trille grandiflore, white trillium, white wake-robin
horizontal, brownish, short, thick, praemorse, not brittle.
short, thick, praemorse.
1–2, round in cross section, 0.8-2 dm, slender to stout, glabrous.
(1–)2–3(–many), round in cross section, 1.5–3+ dm, thick, glabrous.
usually drooping, often touching ground in early anthesis, sessile;
blade pale silvery green, strongly mottled in 3 or more shades of dark green and bronze, sometimes maroon, mottling becoming obscure with age, ovate-lanceolate to obovate, 6.5–12 × 5–7.8 cm, margins of distal 1/3 straight from rounded base to apex, apex acuminate.
sessile or subsessile (occasionally weakly cuneate basally);
blade dark green with maroon overtones early, ovate-rhombic, 12–20 × 8–15 cm, apex acuminate.
erect, odor fetid, especially when first open;
sepals displayed above bracts, spreading, green or purple on adaxial surface, lanceolate, 4.5–5 × 8–12 mm, margins entire, flat, apex rounded-acute;
petals long-lasting, erect-spreading, ± connivent, ± concealing stamens and ovary or at least partially obscuring stamens, tips ± incurved, dark maroon-red, or purplish red, brownish maroon, or yellowish green, not spirally twisted, oblanceolate to elliptic, 3–5.5+ × 1–1.5 cm, usually 3–4 times longer than wide, thick-textured, margins entire, apex acute;
stamens ± erect to weakly incurved, 14–17 mm;
filaments purple, 1–2 mm;
anthers 8–15 mm, thick, dehiscence latrorse;
connectives brown-purple, straight, extended 1–2 mm beyond anther sacs, apex somewhat acute;
ovary purple, ellipsoid, 6-angled, 6.3–11 mm;
stigmas erect, abruptly recurved upon ovary, distinct, purplish, linear, 1.5–5 mm, slightly thickened basally, 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.
baccate, purple-black to dull greenish maroon, odorless, ovoid to obovoid, 6-angled (-ridged), 0.7–1 cm diam., pulpy, not juicy.
pale green, odorless, ± globose, obscurely 6-angled, 1.2–1.6 × 0.8–1.4 cm, mealy, moist (not juicy).
= 10.
Trillium underwoodii
Trillium grandiflorum
Trillium underwoodii can cause considerable confusion for the beginning student of the genus. In some ways it closely resembles a small-statured T. cuneatum. As T. underwoodii continues to expand after flowering, it may become somewhat taller and less “ground hugging,” and it then appears similar to a smaller plant of T. decipiens, which grows in parts of the same range, especially when its bracts do not touch the ground at anthesis. It also has vague similarities to T. reliquum, with which it grows sympatrically in parts of its range. Care should be taken to observe the details of floral structure accurately.
Distribution of Trillium underwoodii is much more restricted than that given by J. K. Small (1933), who indicated a range extending from Alabama to North Carolina and Arkansas.
(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.)
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