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brook trillium, brook wake-robin

mottled wakerobin, pale yellow trillium, small yellow toadshade

Rhizomes

horizontal, short, praemorse, fleshy.

horizontal, brownish, short or somewhat compressed-thickened, bulblike, praemorse, not brittle.

Scapes

1–2, round in cross section, 0.4–1.5 dm, slender, glabrous.

1–2, 1–2.2 dm, slender, essentially 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.

held well above ground, sessile;

blade mottled dark green over lighter green, mottling fading or blurring with time, ovate, elliptic to almost circular, 6–13 × 4–7 cm, apex acute to acuminate.

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, odor faintly pleasant, resembling sweetshrub (Calycanthus sp.);

sepals displayed above bracts, spreading, green, oblong-lanceolate, shorter than petals, 20–30 × 7–19 mm, margins entire, apex acute;

petals long-lasting, erect, ± connivent, ± concealing stamens and ovary to spreading distally, soft pale sulfur-yellow, fading to ± cream, sometimes slightly spirally twisted, widely spatulate, clawed basally, 2.2–5 × 0.9–1.5 cm, thick-textured, margins entire, often upraised adaxially, at least 1 petal with apex strongly apiculate, nipplelike, others with apex apiculate-acuminate;

claw green, sometimes obscurely marked or mottled with purple, broadly cuneate;

stamens incurved-erect, 8–15 mm;

filaments purple, 1–2.5 mm;

anthers erect, straight or arcuate, brown, 6.5–14 mm, dehiscence introrse-latrorse;

connectives straight, extending 1–2 mm beyond anthers;

ovary purplish, ovoid, 6-ridged, 2.5–8.5 mm;

stigmas divergent to erect, distinct, purplish white, subulate, short, 2–6 mm, ± fleshy.

Fruits

greenish white, odorless, globose, 0.9–1.2 × 0.8–1 cm, pulpy, not juicy.

baccate, greenish white, subglobose, weakly 6-winged, 1–5 × 1 cm, pulpy or mealy, not juicy.

2n

= 10.

= 10.

Trillium rivale

Trillium discolor

Phenology Flowering spring (early Mar–early Jun); withering in summer. Flowering spring (mid Apr–early May).
Habitat Open, grassy hillsides, manzanita shrubbery, pine groves, clearings in sequoia groves, roadside banks, ledges, gravelly talus Rather acidic to clearly circumneutral or basic soils of mixed deciduous forests, often under oaks, near Rhododendron thickets, or near tangles of Leucothoë on moist stream banks, slopes near streams
Elevation 10–1400 m (0–4600 ft) 100–200 m (300–700 ft)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
from FNA
GA; NC; SC
[WildflowerSearch map]
[BONAP county map]
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 discolor occurs only in the upper drainage of the Savannah River, but it is locally frequent within its limited range.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 26, p. 102. FNA vol. 26, p. 109.
Parent taxa Liliaceae > Trillium > subg. Trillium Liliaceae > Trillium > subg. Phyllantherum
Sibling taxa
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, T. chloropetalum, T. cuneatum, T. decipiens, T. decumbens, T. discolor, T. erectum, T. flexipes, T. foetidissimum, T. gracile, T. grandiflorum, T. kurabayashii, T. lancifolium, T. ludovicianum, T. luteum, T. maculatum, T. nivale, T. ovatum, T. parviflorum, T. persistens, T. petiolatum, T. pusillum, T. recurvatum, T. reliquum, T. rugelii, T. sessile, T. simile, T. stamineum, T. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride, T. viridescens
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, T. chloropetalum, T. cuneatum, T. decipiens, T. decumbens, T. erectum, T. flexipes, T. foetidissimum, T. gracile, T. grandiflorum, T. kurabayashii, T. lancifolium, T. ludovicianum, T. luteum, T. maculatum, T. nivale, T. ovatum, T. parviflorum, T. persistens, T. petiolatum, T. pusillum, T. recurvatum, T. reliquum, T. rivale, T. rugelii, T. sessile, T. simile, T. stamineum, T. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride, T. viridescens
Name authority S. Watson: Proc. Amer. Acad. Arts 20: 378. (1885) T. Wray ex Hooker: Bot. Mag. 58: plate 3097. (1831)
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