Nigritella Richard.

Herbs, terrestrial, medium-sized, slender to robust. Tubers palmately lobed, fleshy, neck with several slender, slightly fleshy roots. Stem erect, terete, fleshy, glabrous, leafy. Leaves cauline, alternate, linear-ligulate to elliptic, basally conduplicate and sheathing stem. Inflorescence capitate to elongate, with a few lanceolate sterile bracts proximally and many flowers in a dense terminal raceme; floral bracts shorter than, equal to, or slightly longer than ovary. Flowers resupinate, small to medium-sized; ovary usually twisted, narrowly cylindric or fusiform, glabrous. Sepals free, spreading; dorsal sepal concave; lateral sepals reflexed. Petals connivent with dorsal sepal and forming a hood, straight, slightly shorter than sepals; lip broadly rhombic to obovate, concave at base, spurred, conspicuously 3-lobed to entire; spur often slightly arcuate, cylindric, longer or shorter than ovary, apex obtuse or bilobed. Column short; anther oblong or ovoid, 2-locular; pollinia 2, clavate, granular-farinaceous, sectile, each with a slender caudicle attached to a separate viscidium; viscidia naked, narrowly oblong to elliptic; rostellum small to elongate, inconspicuously 3-lobed; staminodes 2, small, subglobose, placed laterally at base of anther; stigma distinctly 2-lobed, rather large, placed at base of column. Capsule erect.

About 16 species: throughout Europe and parts of C and E Asia, the Himalayas, and Japan; five species (three endemic) in China.

(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Stephan W. Gale, Phillip J. Cribb)