PlantaeDB Logo
Login Sign-up

Genus Stemona in Family Stemonaceae

In botanical taxonomy, a genus (plural genera) is a rank used to group closely related species within a family. In the hierarchy, genus sits below family and above species.

Genera are defined by shared morphological, anatomical, and genetic characteristics (for example, features of flowers, fruits, seeds, or leaves) that indicate a close evolutionary relationship among the species they contain.

Each genus can include one or more species. Examples include Rosa (roses) and Solanum (nightshades, including tomato and eggplant).

Do you wish to read more about plant taxonomy? Click here!

Genus Description

Suggest a correction!

Stemona (Lour.), the type genus of Stemonaceae within Dioscoreales, comprises about 30 species of twining herbs distributed from South and Southeast China through mainland Southeast Asia to Malesia, with occasional occurrence in northern Australia and parts of the Pacific (POWO, 2024; GBIF, 2024). Plants form swollen, often J-shaped or coiled tubers and typically bear lanceolate, entire to slightly lobed leaves with reticulate venation and sometimes reduced or ephemeral stipules; indumentum varies from glabrous to pubescent. Inflorescences are axillary and few‑flowered; flowers are small with six tepals arranged in two whorls and a central androecium often said to comprise two whorls of stamens, anthers opening by slits or pores; the ovary is superior with axile placentation and matures into a dehiscent capsule bearing flattened seeds bearing long apical hairs that favor ant dispersal (Caddick et al., 2002; Duyfjes, 2010). The genus is best defined by its twining habit and characteristic J‑shaped tubers; in the field, Stemona is readily distinguished from the allied genera Croomia and Pentastemona by its climbing vine growth form and tuber morphology (Duyfjes, 2010).

Diversity and distribution are concentrated in China–Indochina and the northern Malay Peninsula, with several local endemics (e.g., in Hainan and Taiwan) and a few taxa extending into Malaysia, Indonesia, and northern Australia; species occur in open woodlands, riverbanks, and secondary growth from near sea level to mid‑elevations (Duyfjes, 2010). Pollination has seldom been recorded; the flowers are small and likely entomophilous, but specific mechanisms remain poorly documented. Fruits are dehiscent capsules, and seeds with apical hairs indicate myrmecochory (Caddynak et al., 2019). Chromosome numbers within Stemonaceae are mostly reported around a base of x=7, although counts for Stemona are not comprehensively surveyed (Duyfjes, 2010).

Taxonomically, Stemona has long been treated as the type of Stemonaceae; recent molecular phylogenetics consistently places the family within Dioscoreales and resolves Stemona as sister to a clade containing Croomia and Pentastemona (Chase et al., 2016; Caddick et al., 2002). Infrageneric groupings have been proposed historically (subgenera Stemona and Roxburghia), but neither broad morphological sectional schemes nor molecular clades are currently robustly supported across the entire genus, and synonymizations (especially under the older name Roxburghia) are not universally accepted (Mabberley, 2017; Duyfjes, 2010). Consequently, circumscription and sectional taxonomy remain provisional. Human relevance is primarily horticultural and edaphic: Stemona tuberosa is cultivated as a leafy vegetable in parts of China and Southeast Asia and sometimes used for root tubers, though pharmacological claims fall outside this scope; weedy behavior is not prominent (Duyfjes, 2010; WFO, 2024). Given the concentration of diversity in regions undergoing land‑use change and habitat fragmentation, regional conservation assessments and taxonomic clarity are priorities; improved phylogenomic resolution is needed to stabilize sectional treatment and define conservation units.

Pick a Species to see its components: