Trillium sessile

Linnaeus

Sp. Pl. 1: 340. 1753.

Common names: Sessile trillium toad trillium toadshade
Endemic
Treatment appears in FNA Volume 26. Treatment on page 115. Mentioned on page 96, 110.

Rhizomes horizontal, brownish, thick, praemorse, fleshy. Scapes 1–3, round in cross-section, 0.8–2.5 dm, slender to stout, glabrous. Bracts 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). Flower 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. Fruits baccate, dark greenish purple, odorless, subglobose, 6-angled, angles somewhat winglike, pulpy, not juicy. 2n = 10.


Phenology: Flowering spring (Mar–early May).
Habitat: Rich woodlands, limestone districts, calcareous soils, floodplains, riverbanks, clayey alluvium, less fertile soils, high, dry limestone woods, persists under light pasturing, in fencerows and brushy areas after lumbering
Elevation: 100–300 m

Distribution

V26 139-distribution-map.jpg

Ala., Ark., Ill., Ind., Kans., Ky., Md., Mich., Mo., N.Y., N.C., Ohio, Okla., Pa., Tenn., Va., W.Va.

Discussion

Trillium sessile is rather uniform throughout its range, with few color forms.

Selected References

None.

Lower Taxa

None.

"thick" is not a number."compressed-shortened" is not a number. "elongated" is not a number."thick" is not a number."dm" is not declared as a valid unit of measurement for this property."thicker" is not a number.

... more about "Trillium sessile"
not juicy +
versatile +  and dorsifixed +
more or less equaling or longer +
cordate +  and linear +
0.9 cm9 mm <br />0.009 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
gradually rounded-tapered +  and acute +
Frederick W. Case Jr. +
Linnaeus +
whorled +, opposite +  and alternate +
dilated +
reticulate-veined +  and parallel-veined +
mottling +, green +  and bluish green +
4 cm40 mm <br />0.04 m <br /> (10 cm100 mm <br />0.1 m <br />) +
oval +  and suborbicular +
2 cm20 mm <br />0.02 m <br /> (8 cm80 mm <br />0.08 m <br />) +
not mottled +, , +, mottled in darker green or bronze +  and green +
mottled +  and green +
1;several +
obovate;elliptical +
tunicate +  and scaly +
thin-walled +
Sessile trillium +, toad trillium +  and toadshade +
purplish brown +
Ala. +, Ark. +, Ill. +, Ind. +, Kans. +, Ky. +, Md. +, Mich. +, Mo. +, N.Y. +, N.C. +, Ohio +, Okla. +, Pa. +, Tenn. +, Va. +  and W.Va. +
yellowish +  and white +
100–300 m +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
pungent +
unisexual +  and bisexual +
dark greenish +
odorless +
6-angled +  and subglobose +
Rich woodlands, limestone districts, calcareous soils, floodplains, riverbanks, clayey alluvium, less fertile soils, high, dry limestone woods, persists under light pasturing, in fencerows and brushy areas after lumbering +
paired +, paniculate +  and racemose +
persistent +
greenish white +, yellowish green +, green +, brownish maroon +  and maroon +
1.7 cm17 mm <br />0.017 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
concealing +
narrowed;6-angled;ovoid;globose +
0.4 cm4 mm <br />0.004 m <br /> (0.85 cm8.5 mm <br />0.0085 m <br />) +
thick-textured +
0.7cm;2cm +
many;several +
zygomorphic +  and actinomorphic +
bicolored +, white +, green +, yellow +, maroon +  and dark purple +
long-lasting +
distinct +
clawed;obovate;linear +
Flowering spring (Mar–early May). +
parietal +  and axile +
6-lobed +  and 3-lobed +
branched +, unbranched +  and monopodial +
subterranean +
praemorse +
straight +
erect +  and arising +
slender +  and stout +
wind-distributed +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
alternating +
streaked with maroon +  and green +
persistent +
distinct +
lanceolate-oblanceolate +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
divergent +  and alternating +
yellowish green;green;yellowish green;green;brownish maroon;maroon +
adnate +  and free +
1.7cm;3.5cm +
incurved +  and erect +
concealing +
narrowed +, orbicular +, oblanceolate +  and elliptic +
1 cm10 mm <br />0.01 m <br /> (2.3 cm23 mm <br />0.023 m <br />) +
thick-textured +
0.7 cm7 mm <br />0.007 m <br /> (2 cm20 mm <br />0.02 m <br />) +
with very short style +, sessile +  and twisted +
persistent +
divergent-recurved +  and erect +
subulate +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
3 +  and 1 +
Trillium sessile +
Trillium subg. Phyllantherum +
species +
connate +  and distinct +
sepaloid +  and petaloid +
narrower +
rhizomatous +  and scapose +
3 +  and 2 +