Trillium decumbens |
Trillium petiolatum |
|
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decumbent trillium, trailing wakerobin |
Idaho trillium, long-petioled trillium, petioled wakerobin, purple trillium, purple wakerobin, round-leaf trillium |
|
Rhizomes | short, thick. |
± erect, often very deep, praemorse. |
Scapes | 1–2, decumbent, usually by an S-shaped curvature, round in cross section, 0.5–2 dm, somewhat stout, slightly expanded toward bracts, densely puberulent, especially just below bracts and on bases of main bract veins beneath. |
typically 1, vertical but mostly subterranean, round in cross section, 0.4–1.7 dm, robust, glabrous. |
Bracts | appearing early in season, in good condition for only a few weeks after anthesis, dying back to semipersistent bases early, resting on ground surface, sessile; blade strongly mottled in shades of green and bronze and with silvery overlay, mottling becoming obscure with age, ovate to suborbicular, 4–12 × 3.3–7 cm, apex acute to rounded. |
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 unreported; sepals divergent, green- or maroon-streaked, lanceolate-ovate, 22–48 × 9–14 mm, margins entire, flat, apex acute; petals long-lasting, rigidly erect, ± connivent, ± concealing stamens and ovary, dark maroon-purple when fresh, fading especially distally to dull reddish brown, greenish brown, or with creamy yellow tones, very rarely pale lemon yellow forms occur, twisted (but not spiraled), linear-lanceolate or oblanceolate, 4–8+ × 0.7–1 cm, thick-textured, margins entire, apex acute; stamens erect, straight, dark purple, 10–25 mm; filaments dark purple, 2–5 mm; anthers straight, dark purple, 9–20 mm, dehiscence extrorse; connectives broad, extending to 3.5–4 mm beyond anther sacs; ovary dark purple, oval, 6-angled, 5–10 mm; stigmas erect, divergent-recurved, distinct, sessile, pink or white, subulate, 4.5–8 mm. |
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, dark purple, broadly ovoid to subglobose, crownlike, strongly ridged, 1–1.5 × 1 cm, pulpy but not juicy, present and enlarging on naked scapes until early autumn. |
fragrance not reported, ovoid, strongly angled/winged, ca. 1 cm, pulpy, moist. |
2n | = 10. |
= 10. |
Trillium decumbens |
Trillium petiolatum |
|
Phenology | Flowering late winter–spring (mid Mar–Apr). | Flowering spring (early Apr–late May). |
Habitat | Thin, open rocky wooded slopes, mature deciduous woodlands, rocky talus and disintegrating shale, flats (floodplains) of small streams and adjacent slopes near river entrance | 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 | 50–200 m (200–700 ft) | 400–1400 m (1300–4600 ft) |
Distribution |
AL; GA; TN
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ID; OR; WA
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Discussion | Trillium decumbens occurs in the Ridge and Valley and Cumberland Plateau physiographic provinces. It has a large, deep, horizontal rhizome, the growing point of which always faces downslope. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 26, p. 109. | FNA vol. 26, p. 113. |
Parent taxa | Liliaceae > Trillium > subg. Phyllantherum | Liliaceae > Trillium > subg. Phyllantherum |
Sibling taxa | ||
Name authority | Harbison: Biltmore Bot. Stud. 1: 158. (1902) | Pursh: Fl. Amer. Sept. 1: 244. (1814) |
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