Trillium sessile |
Trillium nivale |
|
---|---|---|
sessile trillium, sessile-flower wake-robin, toad trillium, toadshade |
dwarf white trillium, snow trillium, snow wakerobin |
|
Rhizomes | horizontal, brownish, thick, praemorse, fleshy. |
short, praemorse. |
Scapes | 1–3, round in cross section, 0.8–2.5 dm, slender to stout, glabrous. |
usually 1, 6-gonal in cross section, 0.3–0.5 dm at onset of anthesis, expanding to 0.45–0.8 dm, slender, 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). |
distinctly petiolate; blade bluish green, elliptic-ovate to ovate, 1.5–4.5 cm × 0.7–34 mm, base abruptly rounded to petiole, apex round-obtuse. |
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. |
erect, fragrance sweet; sepals spreading, flat, bluish green, lanceolate, 10–32 × 2–7 mm, shorter than petals, margins entire, apex obtuse; petals very showy, recurved to erect-spreading, white, veins not engraved on adaxial surface, ovate-elliptic to oblong, 1.5–3.5+ × 0.8–1.5 cm, thin- to firm-textured, margins entire to slightly wavy, apex obtuse-acuminate; stamens straight, 5–18 mm; filaments white, slightly shorter than anthers, slender; anthers straight, pale yellow, 2.5–11 mm, thin, dehiscence introrse; ovary greenish white, ± globular, obtusely 3-angled; style with tips spreading, elongate, 0.5–1.5 mm, slender; stigmas prominent, recurved or curled, connate basally, white, linear, threadlike, 4–12+ mm; pedicel erect in anthesis, rapidly recurving below leaves after pollination, 5–20 cm. |
Fruits | baccate, dark greenish purple, odorless, subglobose, 6-angled, angles somewhat winglike, pulpy, not juicy. |
greenish white, odorless, globose-ovate, 0.6–1 × 0.5–0.8 cm, pulpy, not juicy. |
2n | = 10. |
= 10. |
Trillium sessile |
Trillium nivale |
|
Phenology | Flowering spring (Mar–early May). | Flowering spring (early Mar–early Apr). |
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 | Forested, limestone-derived soils, alkaline glacial drift or loess, creeping soils at head of ledges, talus of cliff bases, crevices in limestone cliffs, gravelly deposits on higher floodplain riverbanks |
Elevation | 100–300 m (300–1000 ft) | 100–300 m (300–1000 ft) |
Distribution |
AL; AR; IL; IN; KS; KY; MD; MI; MO; NC; NY; OH; OK; PA; TN; VA; WV
|
IA; IL; IN; KY; MD; MI; MN; MO; NE; OH; PA; SD; WI; WV
|
Discussion | Trillium sessile is rather uniform throughout its range, with few color forms. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Trillium nivale occurs primarily at the southern edge of Pleistocene glaciation and shuns humus, leaf deposits, and much plant competition. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 26, p. 115. | FNA vol. 26, p. 100. |
Parent taxa | Liliaceae > Trillium > subg. Phyllantherum | Liliaceae > Trillium > subg. Trillium |
Sibling taxa | ||
Name authority | Linnaeus: Sp. Pl. 1: 340. (1753) | Riddell: Syn. Fl. West. States, 93. (1835) |
Web links |