Trillium foetidissimum
Trillium parviflorum
fetid trillium, Mississippi River wakerobin, stinking trillium
small-flower trillium
horizontal, brownish, thick, short, praemorse, not brittle.
horizontal to ± erect, brownish, thick, praemorse, not brittle.
1–2, green to maroon, round in cross section, 0.8–2.8 dm, papillose basally.
1–3, round in cross section, 1.7–3 dm, slender to robust, glabrous.
often carried quite horizontally, well above ground, sessile;
blade light green or bronze-green, strongly mottled in dark green with central light green stripe, mottling becoming obscure with age but less so than in most species, elliptic-ovate, rarely ± orbicular, 6.7–12 × 3.8–6 cm, not glossy, base evenly tapered to broad attachment, apex obtuse-acute.
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.
borne directly on bracts, odor of putrid meat, especially when in strong sunlight;
sepals displayed above bracts, carried almost horizontally, green or green streaked with dark maroon, lanceolate, 16–40 × 4–6 mm, thick-textured, margins entire, apex acute;
petals long-lasting, erect, very gradually incurved from base to apex, ± connivent, ± concealing stamens and ovary, pinkish purple, light to reddish purple, brownish purple, rarely yellow, fading to brownish tones with age, not spirally twisted, not inrolling with age, veins not engraved, narrowly elliptic to linear-lanceolate, 2–5 × 0.3–0.5 cm, thick-textured, not glossy, margins entire, flat, acute at apex;
stamens relatively prominent, erect, 9–25 mm;
filaments dark maroon, 3–6 mm, dilated basally;
anthers straight, dark maroon-black, 8–15 mm, dehiscence introrse;
connectives straight, extended 1–1.5 mm beyond anther sacs;
ovary red-purple, ovoid, hexagonal in cross section, 5–12 mm, broadly attached;
stigmas erect, divergent-recurved, distinct, dark purple, subulate, nearly as long as ovary, fleshy.
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.
purplish brown, ovoid, 6-angled at least apically, fleshy.
dark reddish purple or maroon, fragrance not reported, subglobose, ± 1 cm, ± juicy.
= 10.
Trillium foetidissimum
Trillium parviflorum
Trillium foetidissimum seems tolerant of a wide range of soil moistures and types, from low, swampy woods to high, dry bluffs and ravine slopes. This is the only Trillium known to occur within its Louisiana range (J. D. Freeman 1975). Freeman considered it to be closely related to T. sessile.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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.)
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