Mitella integripetala H.Boissieu

M. Wakabayashi, 2006, Tiarella and Mitella, Flora of Japan, Volume 2 b: Angiospermae-Dicotyledoneae: Archichlamydeae (b), Kodansha, pp. 70-75 : 71

2. Mitella integripetala H.Boissieu

in Bull. Herb. Boissier 5: 689 (1897).

Japanese name: Ezo-no-charumeru-so.

Stoloniferous perennial herbs. Rhizomes short creeping, hypogaeous, with slender stolons. Radical leaf blade triangular-ovate, cordate, 3-7 cm long and wide, palmately or shallowly 3-5-lobed, with irregular teeth; upper surface sparsely pilose, lower surface glabrescent; petiole 10-15 cm long, sparsely minutely glandular, with long glandular hairs when young, with a pair of axillary stipules at base. Flowering stems 25-45 cm tall, erect, densely glandular hairy. Cauline leaves (1 or)2(or 3), short petiolate at middle of stem, closely alternate, similar to radical ones but more deeply lobed and acute. Inflorescences racemes 8-16-flowered. Flowers June; pedicel 2-3 mm long, densely minutely glandular. Calyx tube broadly cup-shaped, sparsely minutely glandular, greenish; calyx lobes 5, lanceolate-triangular, acute, 3-nerved, minutely glandular on abaxial surface and on upper half of adaxial surface, 2-2.3 mm long, longer than calyx tube, reflexed at anthesis, dark purplish. Petals 5, subulate-linear, 1-nerved, minutely glandular dotted, 5-6.4 mm long, ca. 0.6 mm wide at base, reflexed at anthesis, reddish purple. Stamens 5, opposite calyx lobes, attached to uppermost margin of calyx tube, ca. 1.6 mm long; anthers ovoid, cordate, ca. 1 mm long just before anthesis, yellow. Ovary subsuperior, minutely glandular on ventral surface of carpels, with dark purplish tinge. Styles 2, horn-like, thick at base and tapering, slightly divergent, with pointed stigma at tip, minutely glandular on ventral surface, ca. as long as ovary, ca. 1.2 mm long, with dark purplish tinge. Seeds oblong, ca. 0.7 mm long, glabrous, smooth, black.

Chromosome number: 2n = 14 (Wakabayashi 1973).

Japan: S. Hokkaido and N. Honshu. Shady and moist places in woods in mountainous areas. Endemic.

Icones: Nakai & Honda, Nov. FI. Jap. 3: f. 34 (1939); Kitamura & Murata, Herb. PI. 2: f. 71 3; Satake et al., Herb. PI. 2: photo. 151 3 & 4.