12. Mitella Linnaeus, Sp. Pl. 1: 406. 1753.
唢呐草属 suo na cao shu
Pan Jintang; Douglas E. Soltis
Herbs perennial. Rhizomes creeping, short. Leaves mainly basal, long petiolate, cauline ones few or absent; stipules scarious; leaf blade simple, cordate or ovate- to reniform-cordate, margin lobed or incised. Inflorescence terminal, racemose, bracteate. Flowers small. Sepals 5. Petals sometimes absent, margin usually pinnately cleft, rarely entire. Stamens 5 or 10. Carpels 2, connate; ovary appearing subsuperior to inferior, 1-loculed; placentas 2, parietal; styles 2. Fruit a capsule, dehiscing between styles. Seeds numerous, ovoid or narrowly ellipsoid, usually tuberculate.
About 20 species: E and N Asia, North America, one species (Mitella nuda) nearly circumboreal: two species (one endemic) in China.
As currently circumscribed, Mitella is not a natural group, but comprises several distinct lineages that should ultimately be treated as distinct genera. Mitella nuda is most closely related to M. diphylla from E North America, whereas M. formosana is most closely related to other Asian species of Mitella that appear to form a lineage distinct from all other species currently placed in the genus.