Trillium underwoodii |
Trillium nivale |
|
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longbract wakerobin, Underwood's trillium |
dwarf white trillium, snow trillium, snow wakerobin |
|
Rhizomes | horizontal, brownish, short, thick, praemorse, not brittle. |
short, praemorse. |
Scapes | 1–2, round in cross section, 0.8-2 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 | usually drooping, often touching ground in early anthesis, sessile; blade pale silvery green, strongly mottled in 3 or more shades of dark green and bronze, sometimes maroon, mottling becoming obscure with age, ovate-lanceolate to obovate, 6.5–12 × 5–7.8 cm, margins of distal 1/3 straight from rounded base to apex, apex acuminate. |
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 fetid, especially when first open; sepals displayed above bracts, spreading, green or purple on adaxial surface, lanceolate, 4.5–5 × 8–12 mm, margins entire, flat, apex rounded-acute; petals long-lasting, erect-spreading, ± connivent, ± concealing stamens and ovary or at least partially obscuring stamens, tips ± incurved, dark maroon-red, or purplish red, brownish maroon, or yellowish green, not spirally twisted, oblanceolate to elliptic, 3–5.5+ × 1–1.5 cm, usually 3–4 times longer than wide, thick-textured, margins entire, apex acute; stamens ± erect to weakly incurved, 14–17 mm; filaments purple, 1–2 mm; anthers 8–15 mm, thick, dehiscence latrorse; connectives brown-purple, straight, extended 1–2 mm beyond anther sacs, apex somewhat acute; ovary purple, ellipsoid, 6-angled, 6.3–11 mm; stigmas erect, abruptly recurved upon ovary, distinct, purplish, linear, 1.5–5 mm, slightly thickened basally, 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, purple-black to dull greenish maroon, odorless, ovoid to obovoid, 6-angled (-ridged), 0.7–1 cm diam., pulpy, not juicy. |
greenish white, odorless, globose-ovate, 0.6–1 × 0.5–0.8 cm, pulpy, not juicy. |
2n | = 10. |
|
Trillium underwoodii |
Trillium nivale |
|
Phenology | Flowering mid winter–spring (late Feb–mid Apr). | Flowering spring (early Mar–early Apr). |
Habitat | Rich to dryish deciduous forests of mature or second-growth timber, dominated by oaks or with beech-oaks, occasionally with scattered pines present, flat ground along streams where soil can be fairly moist, rich clay or sand | 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 | 100–200 m (300–700 ft) | 100–300 m (300–1000 ft) |
Distribution |
AL; FL; GA
|
IA; IL; IN; KY; MD; MI; MN; MO; NE; OH; PA; SD; WI; WV
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Discussion | Trillium underwoodii can cause considerable confusion for the beginning student of the genus. In some ways it closely resembles a small-statured T. cuneatum. As T. underwoodii continues to expand after flowering, it may become somewhat taller and less “ground hugging,” and it then appears similar to a smaller plant of T. decipiens, which grows in parts of the same range, especially when its bracts do not touch the ground at anthesis. It also has vague similarities to T. reliquum, with which it grows sympatrically in parts of its range. Care should be taken to observe the details of floral structure accurately. Distribution of Trillium underwoodii is much more restricted than that given by J. K. Small (1933), who indicated a range extending from Alabama to North Carolina and Arkansas. (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. 116. | FNA vol. 26, p. 100. |
Parent taxa | Liliaceae > Trillium > subg. Phyllantherum | Liliaceae > Trillium > subg. Trillium |
Sibling taxa | ||
Name authority | Small: Bull. Torrey Bot. Club 24: 172. (1897) | Riddell: Syn. Fl. West. States, 93. (1835) |
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