Trillium sessile
Trillium luteum
sessile trillium, sessile-flower wake-robin, toad trillium, toadshade
wax trillium, yellow toadshade, yellow trillium, yellow wakerobin
horizontal, brownish, thick, praemorse, fleshy.
horizontal, brownish, short, thick, praemorse, not brittle.
1–3, round in cross section, 0.8–2.5 dm, slender to stout, glabrous.
1–4, round in cross section, 1.4–4 dm, stout, glabrous.
held well above ground, sessile;
blade green to bluish green, strongly to sparsely mottled, mottling becoming obscure with age, oval to suborbicular, 4–10 × 2–8 cm, base broadly attached, apex rounded-acuminate to bluntly parallel sided-acuminate (rounded basally to its broad attachment).
held well above ground, sessile;
blade mottled, mottling becoming more obscure as growth matures, shape variable, ovate-elliptic to ± orbicular-acuminate, 6.5–17 × 6.5–9.8 cm, not glossy, apex acuminate to long-acuminate.
erect, odor pungent, spicy;
sepals displayed above bracts, spreading, green, variously streaked with maroon, lanceolate-oblanceolate, 9–35 × 4–8 mm, margins entire, apex rounded-acuminate;
petals long-lasting, erect, ± connivent, ± concealing stamens and ovary, maroon, brownish maroon, green, or yellowish green, not spirally twisted, oblanceolate to elliptic, occasionally almost orbicular, 1.7–3.5 × 0.7–2 cm, thick-textured, narrowed near basal attachment (but not truly clawed), margins entire, apex gradually rounded-tapered to acute;
stamens straight, 10–23 mm;
filaments red-purple, 2–5 mm, dilated basally;
anthers erect, straight, gray-purple, 9–16 mm, thick, dehiscence introrse;
connectives purplish brown, straight, projecting 2–5+ mm beyond anther sacs;
ovary greenish white basally, purple distally, ovoid to globose, 6-angled, pyramidally narrowed to stigmas, 4–8.5 mm;
stigmas erect, divergent-recurved, distinct, purple, subulate, 1–5 mm, ± fleshy.
erect, odor strongly lemony;
sepals displayed above bracts, widely spreading, green, oblong-lanceolate, lanceolate, or oblong-elliptic, 22–47 × 8–9 mm, margins entire, apex distinctly rounded-acute;
petals long-lasting, erect, ± connivent, ± concealing stamens and ovary, greenish yellow to lemon yellow, not spirally twisted, not clawed, elliptic-lanceolate, lanceolate, or oblanceolate, 3.4–6.6 × 1–2.1 cm, thick-textured, widest near base, margins entire, tapering to long-acuminate apex;
stamens erect, 11–18 mm;
filaments greenish white, 1.5–2 mm, basally dilated;
anthers erect, straight, yellow, 9–16 mm, dehiscence introrse (or appearing lateral);
connectives green, straight, broad, extending only slightly (to 0.5 mm) or not at all beyond anther sacs;
ovary pale green, ovoid to globose, 6-angled, 5–8 mm;
stigmas erect, barely spreading, distinct, greenish white, sessile, linear to subulate, 3–4 mm, fleshy.
baccate, dark greenish purple, odorless, subglobose, 6-angled, angles somewhat winglike, pulpy, not juicy.
green to greenish white, occasionally with dark streaks, odor not reported, ovoid, 6-angled, 3.5 × 2 cm, pulpy.
= 10.
= 10.
Trillium sessile
Trillium luteum
Trillium sessile is rather uniform throughout its range, with few color forms.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Botanists have been confused by Trillium luteum for a long time. Some, such as A. E. Radford et al. (1968), appear to regard it as a form of T. cuneatum, while others confuse it with T. viride, a more western species. Early botanists confused T. luteum with the occasional individual or very local larger population of pallid color forms of other species. Trillium cuneatum rather frequently produces green, yellowish green, or pale lemon yellow forms (but with a cuneate larger and wider petal) that mimic T. luteum. These forms, when growing with T. luteum, hybridize, leading to so many intergrades that many plants cannot be placed in either species with any confidence. For these reasons, almost no work older than J. D. Freeman’s (1975) can be used reliably to plot distribution of T. luteum.
In some parts of their ranges, Trillium luteum and T. cuneatum do not grow together. Trillium luteum is abundant in eastern Tennessee, extending a short distance into North Carolina and Georgia. Trillium cuneatum is rare or absent from this region except along the Little Tennessee River (J. D. Freeman 1975).
Trillium luteum has escaped and become established along the Grand and Saint Joseph rivers and elsewhere in Michigan, near Kingston and Grimsby, Ontario (J. K. Morton pers. comm.), and probably elsewhere.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
IL Wildflowers
KS Wildflowers
MD Biodiversity
MI Flora
MO Plants
WildflowerSearch
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