16. Trillium albidum J. D. Freeman, Brittonia. 27: 48, fig. 11. 1975.
Rhizomes horizontal, ± erect, brown, superficially bulblike, short, thick, not brittle. Scapes often several from same rhizome terminus, round in cross section, 2.2–5.8 dm, stout. Bracts held well above ground, sessile; blade weakly mottled with scattered, darker green spots, mottling often fading later in season, broadly ovate, 10–20 × 12–15 cm, not glossy, base rounded, apex obtuse. Flower borne directly upon bracts, erect, fragrance roselike; sepals conspicuous, spreading, displayed above bracts, pale green, lanceolate, 30–65 × 12–15 mm, margins entire, apex acute; petals long-lasting, usually erect or slightly spreading, ± connivent, ± concealing stamens and ovary basally, white to creamy white, rarely soft pinkish rose near base, veins prominent but not engraved, not spirally twisted, obovate, more lanceolate in young plants, 4.8–8 × 2.2–3 cm, widest at or just above middle, ± thick-textured, base cuneate, margins entire, ± flat, apex rounded to acute; stamens erect, greenish white, 15–25 mm; filaments whitish green, 3–4 mm, slender; anthers erect, straight, yellow, 11–20 mm, dehiscence latrorse; connectives straight, extended ca. 1 mm beyond anther sacs, rounded; ovary green or occasionally purple, ovoid, rounded 6-gonal, 6–11 mm; stigmas erect to spreading, distinct, sessile, subulate, 4–7 mm, thin distally. Fruits green or purplish green, fragrance unknown, ovoid to globose, pulpy, juicy.
Flowering spring (mid Mar--late Apr). Moist slopes in rich mixed deciduous-coniferous forests or coniferous stands, brushy thickets on flats, open fields, pastures, and fencerows, dense second-growth coniferous forests, floodplains along streams and larger rivers; 100--200 m; Calif., Oreg.