Codonacanthus is a genus of flowering plants in the family Acanthaceae (order Lamiales), native to Assam, Indochina, southern China, and Japan. The genus includes the species Codonacanthus pauciflorus, a perennial erect herb or subshrub reaching 20–60 cm tall with many branches and quadrangular, lightly hairy stems. Its leaves are thin, elliptic to lanceolate, 5–12 cm long, with smooth or slightly wavy margins, green above and paler beneath. The inflorescences are simple racemes or small terminal panicles 3–10 cm long, bearing small, widely spaced white flowers with a bell-shaped corolla 8–10 mm long and two included stamens. The fruit is an oblanceolate capsule about 1.5 cm long containing 2–4 small round seeds. The genus is recognized by GBIF with a single accepted species, though Wikipedia additionally lists C. sanjappae and C. spicatus.
Distribution
Codonacanthus is native to Asia, ranging from Assam (India) through Indochina (Bhutan, Laos, Myanmar, Vietnam, Thailand) and southern China (Hainan, Guangdong, Guangxi, Guizhou, Yunnan, Fujian) to Taiwan, Hong Kong, and Japan.
Ecology
Species in this genus grow in subtropical regions, inhabiting forests and wet ravines. Codonacanthus pauciflorus flowers and fruits from October to January.
