Trillium albidum
Trillium pusillum
giant trillium, giant white wakerobin, sessile trillium, smallflower trillium, white toadshade
dwarf trillium, dwarf wakerobin, least trillium, little trillium
horizontal, ± erect, brown, superficially bulblike, short, thick, not brittle.
horizontal, branching, thin.
often several from same rhizome terminus, round in cross section, 2.2–5.8 dm, stout.
1–2, round in cross section, 0.7–2 dm, slender, becoming taller and more robust after flowering, glabrous.
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.
very short-petiolate, subsessile or sessile;
blade dark green with maroon undertones when young, not mottled, 3–5 major veins from base, oblong to lanceolate-obtuse, 2.5–8+ × 1–3 cm, not glossy, apex obtuse.
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.
above bracts, erect, odorless to faintly sweet, pedicellate or sessile;
sepals conspicuous, spreading to same plane as petals, dark green with maroon undertones when young, oblong-lanceolate, 15–30 × 5–10 mm, margins entire, apex obtuse to strongly rounded;
petals of short duration, spreading-ascending, exposing stamens and ovary, weakly recurved in distal 1/2, white, aging to deep rosy pink abaxially, veins not engraved but major petal veins clearly visible, oblong to narrowly lanceolate, 1.5–3 × 0.5–1.5 cm, thin-textured, widest above base, margins strongly undulate, quite variable in petal width and degree of undulation between individuals and populations, apex obtuse to weakly acute;
stamens erect-spreading, 8–10 mm;
filaments pinkish purple to white, ± equaling or slightly shorter than anthers, slender;
anthers ± straight, pale lavender or yellow, 3–8(–10) mm, thicker than filaments, dehiscence introrse;
connectives not extended beyond anther sacs;
ovary conspicuous, white, ovoid, obscurely 6-angled, 2.5–8 mm, attachment narrower than ovary;
stigmas confluent with style, greenish white to white, distally 3-lobed, lobes linear (threadlike), long-spreading, 3–12 mm, uniformly thin and threadlike;
pedicel stiffly erect to leaning, 0.5–2 cm, or absent to much reduced.
green or purplish green, fragrance unknown, ovoid to globose, pulpy, juicy.
white or pale greenish, ovate, 1–1.5 cm, pulpy, moist but not juicy.
= 10.
Trillium albidum
Trillium pusillum
Varieties 2 (2 in the flora).
Trillium pusillum comprises widely disjunct, regional populations, each varying somewhat from the others and variable within itself as well. Some of these populations have been named as varieties or separate species. In the wild, the plants that have been recognized as var. ozarkanum generally grow taller than others and are said to have bracts with five major veins instead of three. Plants attributed to var. texanum, on the other hand, are generally smaller in all parts, with narrower petals, and often revert to a single bract when not flowering. Only var. virginianum is easily distinguished at sight by its “sessile” flower. This variety has received extensive study. P. R. Cabe (1995), in a morphological study including statistical analysis, found variation within and between populations. He felt that his results were inconclusive, and also that some of the variation might be environmentally induced. The variation that he found did not correlate with a geographic pattern, and he suggested treating all Virginia populations as var. virginianum, or simply T. pusillum. In a later study, P. R. Cabe and C. R. Werth (1995), using isozyme evidence, obtained like results, and suggested treating all Virginia populations as a single variety pending further investigation. Until there has been such study, of the Virginia plants as well as the rest of the T. pusillum complex, I choose to retain the fairly distinctive and more or less traditionally known var. virginianum, and include all other populations in a broadly circumscribed var. pusillum.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Flower pedicillate; pedicel usually 0.5–2 cm. | var. pusillum |
1. Flower sessile or subsessile; pedicel, if present, 0.1–0.3 cm | var. virginianum |
CA
OR
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
