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brook trillium, brook wake-robin

giant purple wakerobin, giant trillium, giant wakerobin, sessile trillium, small-flower trillium

Rhizomes

horizontal, short, praemorse, fleshy.

± erect, brownish, somewhat compressed-thickened, superficially bulblike, praemorse, not brittle.

Scapes

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

1–3, green, round in cross section, 2–6.5 dm, robust.

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 (narrowing of bract blade may give bract subsessile appearance);

blade densely to weakly mottled in dark brownish green, mottling becoming more obscure to absent as bract matures, broadly ovate, 7–17.6 × 7.4–17.7 cm, not glossy, apex obtuse-rounded.

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 roselike, spicy;

sepals spreading-ascending above bracts, green, lanceolate, 35–65 × 7–12 mm, margins entire, flat, apex obtusely rounded;

petals long-lasting, erect, connivent, ± concealing stamens and ovary, yellow, bronze, maroon, brown, deep purple, reddish brown, pink, dark purplish red, purplish bronze, rarely greenish white, not spirally twisted, veins not engraved, oblanceolate to obovate, 6.5–10 × 1.5–2.5 cm, thick-textured, base cuneate, margins entire, apex variably acute to almost truncate, erose;

stamens erect, purplish, 17–26 mm;

filaments purple, ca. 4 mm, widest at base, much shorter than anther sacs;

anthers erect, straight, ± purple-brown, 13–22 mm, dehiscence introrse;

connectives purple, straight, extended ca. 1–1.5 mm beyond anther sacs;

ovary purple, ovoid, 6-angled, 6–12 mm;

stigmas small, divergent or erect, distinct, purple, subulate, 4–8 mm, not fleshy.

Fruits

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

red-purple, fragrance not reported, ovoid, obscurely 6-angled, 2.5–3 cm, pulpy, juicy.

2n

= 10.

= 10.

Trillium rivale

Trillium chloropetalum

Phenology Flowering spring (early Mar–early Jun); withering in summer.
Habitat Open, grassy hillsides, manzanita shrubbery, pine groves, clearings in sequoia groves, roadside banks, ledges, gravelly talus
Elevation 10–1400 m (0–4600 ft)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
from FNA
CA
[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.)

Varieties 2 (2 in the flora).

J. D. Freeman (1975) considered that Trillium chloropetalum differs from T. albidum in having introrse (not latrorse) anther sacs, and that the purple pigments present on anther and ovary tissue here are absent in T. albidum. In some places, hybridization between the two certainly has occurred, and a complete range of intergrades exists.

This species merits further study. The following varieties are only weakly differentiated and perhaps ought to be dropped.

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

Key
1. Petal tissue always with yellow pigments, often present with other pigments; petals yellow, greenish yellow, greenish purple, or bronze-green or brown.
var. chloropetalum
1. Petal tissue lacking yellow pigments; petals purple, reddish purple, garnet red, pink, or greenish white.
var. giganteum
Source FNA vol. 26, p. 102. FNA vol. 26.
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. 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. rivale, T. rugelii, T. sessile, T. simile, T. stamineum, T. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride, T. viridescens
Subordinate taxa
T. chloropetalum var. chloropetalum, T. chloropetalum var. giganteum
Synonyms T. sessile var. chloropetalum, T. giganteum var. chloropetalum
Name authority S. Watson: Proc. Amer. Acad. Arts 20: 378. (1885) (Torrey) Howell: Fl. N.W. Amer., 661. (1902)
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