Trillium underwoodii |
Trillium petiolatum |
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longbract wakerobin, Underwood's trillium |
Idaho trillium, long-petioled trillium, petioled wakerobin, purple trillium, purple wakerobin, round-leaf trillium |
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Rhizomes | horizontal, brownish, short, thick, praemorse, not brittle. |
± erect, often very deep, praemorse. |
Scapes | 1–2, round in cross section, 0.8-2 dm, slender to stout, glabrous. |
typically 1, vertical but mostly subterranean, round in cross section, 0.4–1.7 dm, robust, 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. |
just at or slightly above soil, long-petiolate; blade medium green, not mottled, ovate to elliptic, 7–14 × 5.5–10.2 cm, not glossy, apex obtuse or rounded; petiole arising from scape apex at or near ground surface, 5–12 cm; bract and petiole strongly resembling leaves of Plantago. |
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. |
in axil of bracts at or near ground level, ± erect, odor unknown; sepals erect to widely spreading, often weakly recurved near middle, green, oblong-elliptic to oblanceolate, 22–47 × 7–10 mm, margins entire, apex acute; petals long-lasting, ± connivent, ± concealing stamens and ovary, or erect-spreading early then ± connivent, erect to incurved, light maroon-red, purple, or greenish to yellowish, not spirally twisted, flat, linear-lanceolate, 3–5.5 × 0.4–1 cm, thick-textured, margins entire, apex acute; stamens erect, (15–) 22–30 mm; filaments olive, (3–)5–7 mm, slender; anthers straight, brown or olive, 16–20 mm, slender, dehiscence latrose; connectives yellow or orange, ± not extending beyond anther sacs; ovary white, greenish, purplish distally, ovoid, sharply angled, 4–9 mm; stigmas erect, divergent, distinct, purple or olive, linear-subulate, 7–20 mm, apex somewhat recurved. |
Fruits | baccate, purple-black to dull greenish maroon, odorless, ovoid to obovoid, 6-angled (-ridged), 0.7–1 cm diam., pulpy, not juicy. |
fragrance not reported, ovoid, strongly angled/winged, ca. 1 cm, pulpy, moist. |
2n | = 10. |
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Trillium underwoodii |
Trillium petiolatum |
|
Phenology | Flowering mid winter–spring (late Feb–mid Apr). | Flowering spring (early Apr–late May). |
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 | Lower rocky hillsides just above stream flats, under brush, edges of coniferous and deciduous forests, open grassy glades, river-flats, wet, seasonally swampy ground and edges of sloughs |
Elevation | 100–200 m (300–700 ft) | 400–1400 m (1300–4600 ft) |
Distribution |
AL; FL; GA
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ID; OR; WA
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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.) |
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Source | FNA vol. 26, p. 116. | FNA vol. 26, p. 113. |
Parent taxa | Liliaceae > Trillium > subg. Phyllantherum | Liliaceae > Trillium > subg. Phyllantherum |
Sibling taxa | ||
Name authority | Small: Bull. Torrey Bot. Club 24: 172. (1897) | Pursh: Fl. Amer. Sept. 1: 244. (1814) |
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