Pittonia 1: 32. 1887 ,.
Plants not stoloniferous. Flowering-stems 15–50 (–65) cm. Leaves: petiole 3–10 (–19) cm, short-stipitate-glandular and sparsely long-stipitate-glandular, longer hairs spreading or retrorse, white or reddish-brown; blade cordate-ovate or triangular-cordate, longer than or ± as long as wide, 1.3–7.7 (–9) × 1.2–7.1 (–8) cm, margins 5-lobed or 7-lobed, irregularly crenate or dentate, uniformly ciliate, apex of terminal lobe acute, surfaces short-stipitate-glandular and sparsely long-stipitate-glandular; cauline leaves absent or 1–2, proximal, alternate, petiolate, 0.3–3 × 0.3–1.6 cm. Inflorescences 1–3, closely to remotely 8–35-flowered, 1 (–2) flowers per node, weakly secund or not secund, 15–50 (–65) cm, short-stipitate-glandular and sparsely long-stipitate-glandular proximally, short-stipitate-glandular distally. Pedicels 0.2–1.5 mm, short-stipitate-glandular. Flowers: hypanthium obconic-campanulate, 1.2–1.8 × 1.4–2.2 mm; sepals erect or spreading, whitish, oblong-ovate to oblong-triangular or triangular, (0.6–) 0.9–1.2 × 0.6–1 mm; petals white, sometimes pink or purple-tinged, 3–5-lobed, 1–1.5 mm, lobes linear, lateral lobes ascending; stamens 5, opposite sepals; filaments white, 0.2–0.3 mm; anthers 0.1–0.2 × 0.1–0.2 mm; ovary at least 3/4 inferior; styles spreading, flattened, 0.1–0.2 mm; stigmas indistinctly 2-lobed. Seeds dark reddish-brown or blackish, 0.8–1.4 mm, pitted. 2n = 14.
Phenology: Flowering May–Jul.
Habitat: Moist woods, stream banks
Elevation: 500-2000 m
Calif., Oreg., Wash.
Mitella diversifolia occurs from Klickitat County, Washington, south to El Dorado County, California.