Cyanotis is a genus of mainly perennial flowering plants belonging to the family Commelinaceae, the spiderwort family, within the order Commelinales. The genus was first described by the Scottish botanist David Don in 1825 in his Prodromus Florae Nepalensis, and currently encompasses around 51 accepted species.
Plants in the genus are typically low-growing herbs, often with succulent or somewhat fleshy stems and leaves, and are covered with conspicuous hair — a trait reflected in the genus name. The flowers are small and three-petalled, characteristic of the broader Commelinaceae family, and are often blue, violet, or purple, though white-flowered forms occur.
The genus has a broad Old World distribution, with species native across tropical and subtropical Africa, the Indian Subcontinent, southern China, Southeast Asia, and extending into northern Australia. Several species show wide ranges spanning multiple continents — for example, Cyanotis vaga occurs from tropical Africa and Yemen through the Himalayas, southern China, Indochina, and Java, and Cyanotis arachnoidea spans tropical Africa, the Indian Subcontinent, southern China, and Indochina.
Notable members include Cyanotis somaliensis (cat's ears), cultivated as an ornamental for its striking hairy foliage; Cyanotis lanata, widespread across tropical and southern Africa; and Cyanotis speciosa, ranging from central and southern Africa into Madagascar.
Etymology
The name Cyanotis derives from the Greek kyanos (κυανός), meaning "blue" or "dark blue," and ous/otos (οὖς/ὠτός), meaning "ear," likely alluding to the blue petals and the ear-shaped appearance of the floral bracts or petals in some species.
Distribution
Cyanotis is distributed across the Old World tropics and subtropics, with species native to Africa (including Madagascar), the Indian Subcontinent, southern China, Southeast Asia, and northern Australia. The centre of diversity appears to be in tropical Africa and southern Asia, with individual species ranging as far as Somalia, Saudi Arabia, the Philippines, Taiwan, and Java.
Taxonomy Notes
The genus was established by David Don in Prodromus Florae Nepalensis (1825) and is placed in the family Commelinaceae, order Commelinales, within the monocot class Liliopsida. GBIF recognises approximately 74 taxa under the genus (including infraspecific ranks), while around 51 species are currently accepted. Cyanotis is closely related to Tradescantia and Commelina within the family.
