Mitella koshiensis Ohwi

M. Wakabayashi, 2006, Tiarella and Mitella, Flora of Japan, Volume 2 b: Angiospermae-Dicotyledoneae: Archichlamydeae (b), Kodansha, pp. 70-75 : 74

9. Mitella koshiensis Ohwi

in Bull. Natl. Sci. Mus. Tokyo no. 26: 9 (1949).

Japanese name: Koshi-no-charumeru-so.

Perennial herbs. Rhizomes elongate, thickened, hypogaeous, with a tuft of leaves at apex. Radical leaf blade widely ovate or orbicular, deeply cordate, acute, 3-10 cm long, 3-9 cm wide, shallowly 5-lobed, irregularly incised and toothed, long hirsute above and on nerves on lower surface, greenish; petiole 3-12 cm long, densely long hirsute, with fused axillary stipules at base; stipules scarious, ovate, nearly entire or sparsely minutely glandular along margin. Flowering stems 15-35 cm tall, erect, densely glandular pubescent, hirsute toward base. Inflorescences racemes, many-flowered. Flowers April to May; pedicel ca. 2-4 mm long, minutely glandular. Calyx tube broadly obconical, densely glandular pubescent, greenish or with purplish tinge; calyx lobes 5, triangular, acute, glabrous on adaxial and sparsely glandular on abaxial surfaces, ca. 1.1 mm long, spreading or often reflexed, greenish or with purplish tinge. Petals 5, 5-7-pinnatiparted, glandular dotted, ca. 3.8 mm long, spreading or reflexed, greenish or with slightly purplish tinge; pinnae slender, spreading. Stamens 5, alternate calyx lobes, adjacent to base of petals, ca. 0.7 mm long; anthers broadly ovoid, cordate, ca. 0.6 mm long at anthesis, yellow. Disc prominent, flat, greenish. Ovary inferior. Styles 2, erect, ca. 0.6 mm long; stigmas thickened, shallowly 4-lobed. Seeds oblong, ca. 1 mm long, scabrous, with narrow longitudinal areolae elevated slightly, without papillae, brownish.

Chromosome number: 2n = 28 (Wakabayashi 1973).

Japan: C. Honshu (Niigata and E. Toyama Pref.). Moist, shady places along streams in lowlands. Endemic.

Icones: Satake et al., Herb. PI. 2: photo. 153 5 & 6.