Trillium rivale |
Trillium nivale |
|
---|---|---|
brook trillium, brook wake-robin |
dwarf white trillium, snow trillium, snow wakerobin |
|
Rhizomes | horizontal, short, praemorse, fleshy. |
short, praemorse. |
Scapes | 1–2, round in cross section, 0.4–1.5 dm, slender, 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 | distinctly petiolate; blade bluish green, occasionally with silvery green pattern along major veins, ovate-lanceolate, 1.5–8 × 0.8–6 cm, somewhat thick-textured, glossy, weakly to strongly cordate basally, apex long-acuminate; petiole (0.5–)1–3(–6) cm. |
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, rapidly recurving below bracts after pollination, ± odorless; sepals conspicuous, spreading, green, weakly sulcate, oblong or tapered apically, usually shorter and narrower than petals, 10–23 × 4–8 mm, margins entire, apex rounded-apiculate; petals erect-spreading, not recurved or only in distal 1/2, white (rarely pale pink), usually with dark madder-purple flecks, rarely almost entirely covered with madder-purple, color not changing with age, veins inconspicuous, not engraved, ovate-cordate to ± orbicular, tapered bluntly apically above middle, 1.3–2.8 × 1–2.4 cm, ± thin-textured, base rounded, cuneate, margins entire, mostly without undulations, apex ± apiculate-acuminate; stamens erect, 5–12 mm; filaments white, ± equaling anthers; anthers straight, yellow, 3–6 mm, dehiscence ± extrorse; connectives not extended beyond anther sacs; ovary creamy white, ovoid, weakly 6-angled but angles in close pairs, giving superficial impression of 3-angled ovary, short, 3–9 × 4 mm, somewhat obscured by anthers broadly attached; stigmas recurved and appearing ± lobed adaxially, at least in dried specimens, connate basally to distinct and closely grouped, white or cream, 2–4 mm, uniformly thick, fleshy; pedicel strongly erect at anthesis, strongly recurving and elongating below bracts after pollination, 2.5–11 cm. |
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 | greenish white, odorless, globose, 0.9–1.2 × 0.8–1 cm, pulpy, not juicy. |
greenish white, odorless, globose-ovate, 0.6–1 × 0.5–0.8 cm, pulpy, not juicy. |
2n | = 10. |
= 10. |
Trillium rivale |
Trillium nivale |
|
Phenology | Flowering spring (early Mar–early Jun); withering in summer. | Flowering spring (early Mar–early Apr). |
Habitat | Open, grassy hillsides, manzanita shrubbery, pine groves, clearings in sequoia groves, roadside banks, ledges, gravelly talus | 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 | 10–1400 m (0–4600 ft) | 100–300 m (300–1000 ft) |
Distribution |
CA; OR
|
IA; IL; IN; KY; MD; MI; MN; MO; NE; OH; PA; SD; WI; WV
|
Discussion | Trillium rivale is confined to the Klamath and Siskiyou mountains of southwestern Oregon and California. It has a strong affinity for banks along streams and adjacent to trickles in Darlingtonia bogs, mainly on serpentine soils. After flowering, the entire plant may enlarge and become more robust and turgid with very glossy leaves. (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. 102. | FNA vol. 26, p. 100. |
Parent taxa | Liliaceae > Trillium > subg. Trillium | Liliaceae > Trillium > subg. Trillium |
Sibling taxa | ||
Name authority | S. Watson: Proc. Amer. Acad. Arts 20: 378. (1885) | Riddell: Syn. Fl. West. States, 93. (1835) |
Web links |