Trillium sulcatum
Trillium parviflorum
Barksdale trillium, furrowed wakerobin, southern red trillium
small-flower trillium
horizontal–slightly erect, thick, praemorse.
horizontal to ± erect, brownish, thick, praemorse, not brittle.
1–4+, round in cross section, 3–7 dm, 2–2.5 times as long as bract, stout, glabrous.
1–3, round in cross section, 1.7–3 dm, slender to robust, glabrous.
subsessile;
blade obovate to broadly elliptic, 13–20 × 8–22 cm, not glossy, base attenuate, 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.
facing outward at right angle to pedicel, above bracts, odor faintly musty, like fresh fungus;
perianth gaping, strongly 3-dimensional;
sepals spreading, usually streaked or entirely purplish maroon, occasionally entirely green except on margins, elliptic, 15–38 × 9–15 mm, margins entire, apex strongly sulcate-acuminate;
petals carried somewhat forward to recurved-spreading in distal 1/2, usually dark reddish maroon to purplish, rarely cream to soft yellow, pink, white, or 2-colored, heavy-veined, ovate to broadly ovate-overlapping, 1.8–5 × 1–3 cm, heavy-textured, apex acuminate, rarely somewhat sulcate;
stamens erect, ± equaling or slightly longer than ovary, 15–18 mm;
filaments purple to white, 3–5 mm, slender;
anthers straight, purplish to yellow, 5–12 mm, thick, dehiscence introrse;
connectives equaling or ± shorter than anther sacs;
ovary usually dark purple, globose to flask-shaped, 6-angled, 14–18 mm, broadly attached basally;
stigmas prominent, recurved, distinct, purple, not lobed adaxially, basally thickened, gradually tapered, 2–5 mm, fleshy;
pedicel usually stiffly erect (rarely almost horizontal above bracts), straight, reflexed ± 90° at tip, 6–11 cm.
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.
red, fragrance of fresh mushrooms, ± globose to pyramidal, 1.5–3 × 1.2–2.8 cm, juicy to pulpy.
dark reddish purple or maroon, fragrance not reported, subglobose, ± 1 cm, ± juicy.
= 10.
= 10.
Trillium sulcatum
Trillium parviflorum
Trillium sulcatum is present mainly on the Cumberland Plateau and is absent from the Great Smoky Mountains and the southern Blue Ridge Mountains.
T. S. Patrick (1984) described Trillium sulcatum flowers as “relatively small and turned downward.” This is true of plants from the type locality; however, in most plants of the Cumberland Plateau, the flowers are quite large and flattened, and the petals are recurved distally and face outward.
(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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