10. Calla Linnaeus, Sp. Pl. 2: 968. 1753.
水芋属 shui yu shu
Authors: Heng Li, Peter C. Boyce & Josef Bogner
Aroides Heister ex Fabricius; Callaria Rafinesque; Provenzalia Adanson.
Herbs, perennial. Rhizome creeping. Leaves several, distichous; petiole sheathing; sheath ligulate, long; leaf blade broadly ovate-cordate to cordate-orbicular, apex acute to acuminate; venation parallel-pinnate. Inflorescence solitary, flowering with leaf appearance; peduncle erect. Spathe persistent, fully expanded, elliptic to ovate, base decurrent, apex acuminate. Spadix stipitate, cylindric, apex obtuse. Flowers numerous, densely arranged, bisexual, naked (perigone absent), only uppermost flowers often male. Stamens free, usually 6, sometimes more (9-12); filaments flattened; anthers dorsifixed; connective short and slender; thecae ellipsoid, dehiscing by longitudinal slit; pollen grains diaperturate, globose, small, exine foveolate and apertural exine verrucate. Pistil ovoid, 1-loculed; ovules 6-9 (rarely more), anatropous and oblong; funicle distinct; placenta basal; stylar region attenuate; stigma subhemispheric, small. Infructescence subglobose to broadly ellipsoid. Berry globose-conic, with many seeds (usually 4-9). Seed oblong-cylindric to somewhat ellipsoid; testa thick, scrobiculate toward chalaza and sulcate-striate toward micropyle; raphe prominent; embryo axile, elongate; endosperm copious. 2n = 36, 54, 72.
One species: N temperate regions and subarctic areas of Asia, Europe, and North America, including China.