Mitella nuda L.

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

1. Mitella nuda L. ,

Sp. PL: 406 (1753).

Tiarella unifolia Retz ., Observ. Bot. 3: 30 (1783).

Mitella reniformis Lam ., Encycl. 4: 196 (1797).

Mitella cordifolia Lam ., Encycl. 4: 196 (1797).

Japanese name: Maruba-charumeru-so.

Evergreen perennial herbs. Rhizomes slender, long creeping and branched, glandular, stoloniferous; leaves on rhizome alternate. Radical leaves few; blade ovate-orbicular, subcordate, 1.5-3.5 cm long and wide, shallowly crenate with pointed teeth, sparsely pilose on both surfaces; petiole 5-10 cm long, slender, appressed glandular hairy, with a pair of axillary stipules at base. Flowering stems 15-25 cm tall, slender, erect, densely short glandular hairy. Cauline leaves none, rarely 1, short petiolate. Inflorescences racemes sparsely 3-10-flowered. Flowers June; pedicel to 4 mm long, glandular hairy. Calyx tube broadly cup-shaped, glandular; disc on inner surface 10-lobed, thin; calyx lobes 5, triangular-ovate, acute, 3-nerved, minutely glandular on both surfaces, ca. 1.4 mm long, obliquely spreading and reflexed, pale green with pale purplish tinge. Petals 5, 9-pinnatiparted, not glandular, ca. 4.8 mm long, spreading or reflexed, pale green or pale purplish; pinnae slender, spreading. Stamens 10, ca. 1 mm long, attached to uppermost margin of calyx tube; anthers rounded, cordate, ca. 0.6 mm long just before anthesis, whitish yellow. Ovary half inferior, dome-shaped with slender styles apically, minutely glandular, with purplish tinge. Styles 2, divergent not glandular, ca. 0.6 mm long; stigma apical, pointed. Seeds few, broadly oblong, ca. 1.2 mm long, glabrous, smooth, black.

Chromosome number: 2n = 14 (Wakabayashi 1973), 28. Japanese plants are diploid (2n = 14).

Japan: C. to E. Hokkaido and C. Honshu (SE. Nagano Pref.). Mossy and shady places in woods in mountains; lowlands in Hokkaido; 1500-2000 m in Honshu.

Distr.: Siberia to Ussuri, Japan, North Korea, NE. China and North America.

Icones: Nakai & Honda, Nov. FI. Jap. 3: f. 33 (1939); Kitamura & Murata, Herb. PI. 2: f. 71 1 & 2; Satake et al., Herb. PL 2: photo. 151 1 & 2.