Trillium kurabayashii
Trillium parviflorum
giant purple wakerobin
small-flower trillium
horizontal, brownish, thick, praemorse, not brittle.
horizontal to ± erect, brownish, thick, praemorse, not brittle.
often 2 from single terminal bud, round in cross section, 2.5–5.5 dm, stout, glabrous.
1–3, round in cross section, 1.7–3 dm, slender to robust, glabrous.
held well above ground, sessile;
blade bright green (in early anthesis rather succulent in appearance), usually well-marked with lighter and darker green spots, occasionally obscurely or scarcely mottled, mottling becoming obscure with age, ovate to broadly ovate, 11–18 × 12–17 cm, somewhat glossy, apex acuminate.
held well above ground, sessile;
blade green with widely scattered mottling, mottling becoming obscure with age, ovate to broadly ovate, 6.5–16 × 5–8 cm, not glossy, apex obtuse.
odor spicy in fresh flowers, becoming fetid in older flowers;
sepals displayed above bracts, spreading, divergent, green, purple-streaked, lanceolate, 40–75 × 10–14 mm, margins entire, apex acute to round-acute;
petals long-lasting, conspicuous, spreading-erect to erect, tips incurving slightly, ± connivent, partially to completely concealing stamens and ovary, glossy dark maroon-red or purple, not spirally twisted, flat, oblanceolate, 5.5–11 × 2–3.5 cm, widest at or below middle, glossy, thick-textured, cuneate basally, margins ± flat, entire, apex round-acute;
stamens erect, straight, 15–26 mm, slightly concealing ovary;
filaments dark purple, 2–4 mm;
anthers dark maroon, 13–24 mm, dehiscence introrse;
connectives straight, barely extended beyond anther sacs;
ovary inconspicuous, purple, ovoid, round to 6-angled, 8–15 mm;
stigmas erect, distinct, subulate, 6–8 mm, fleshy, thickened basally.
erect, odor spicy, of cloves;
sepals displayed above bracts, spreading, divergent, green, lanceolate, 16–25 × 4–8 mm, margins entire, flat, apex variously obtuse to rounded;
petals long-lasting, erect to erect-spreading, ± connivent, ± concealing stamens and ovary, white, occasionally purple stained basally, sometimes weakly spirally twisted, linear to linear-lanceolate, 2.2–4.5 × 0.4–1 cm, thin-textured, base occasionally cuneate, margins entire, apex obtuse;
stamens erect, 10–15.5 mm;
filaments white, greenish white, or purple stained, 1–3 mm, much shorter than anthers, slender;
anthers erect, straight, greenish white, 9–11+ mm, ± slender, dehiscence latrorse;
connective greenish, straight, barely extended (to 0.4 mm) beyond anther sacs;
ovary green or green and purple basally, ovoid, obscurely 6-gonal, 4–8 mm;
stigmas erect, ± divergent, distinct, green, outer surface purple, subulate, 3–4.5 mm, ± fleshy, thickened.
dark reddish purple, ovoid to ellipsoid or weakly angled, 20–50 mm, fleshy.
dark reddish purple or maroon, fragrance not reported, subglobose, ± 1 cm, ± juicy.
= 10.
Trillium kurabayashii
Trillium parviflorum
Trillium parviflorum varies from very short, slender, small-bracted plants to tall, broad, umbrella-bracted giants. Regardless of plant or bract sizes, flower and petal sizes are remarkably constant, all plants having small, linear-lanceolate petals. This is not usually the case with T. albidum, the species with which this plant is most likely to be confused. In T. albidum also the plants can be enormous, but when they are, the petals are very long, broad, and conspicuously obovate-diamond-shaped. In large clonal clumps of T. albidum, the larger and more mature offsets show the typical petal shape, while the smaller and presumably youngest offsets sometimes produce smaller, narrower petals, more like those of T. parviflorum.
Some western botanists, more experienced with local populations than I, do not consider Trillium parviflorum to be distinct from T. albidum. They point out that since there is an extensive region of apparent intergradation (as indeed there is, well supported by herbarium vouchers), there exists a morphological cline from the long- and wide-petaled T. albidum to the narrower- and generally shorter-petaled T. parviflorum, and that T. parviflorum, therefore, should not be considered a separate species but rather a subspecies or a variety. Since no one to date has treated T. parviflorum at the subspecific or varietal level, and since in my own limited experience it does appear as a distinct species in Washington north of the Columbia River, I include it here as treated by Soukup. I have seen populations of considerable variation north of Corvallis, Oregon, and agree that there is much overlap with T. albidum. Obviously there is need for a much more extensive study of this situation.
A factor that exacerbates this problem (and many others in Trillium), is that nutrition, age, and even favorable position in the habitat can greatly influence plant and floral organ sizes. In many species, including T. albidum, when a single vigorous clonal clump produces many offsets, the oldest offsets may have flowers with very large petals, sepals, ovary, etc., while the younger offsets may have organs only half the size. In most sessile trilliums particularly, population averages are often more useful than isolated individual measurements, a difficult situation, indeed.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
