Calanthe, commonly known as Christmas orchids, is a genus of approximately 220 species of terrestrial orchids belonging to the family Orchidaceae, within the order Asparagales. The genus was first formally described in 1821 by the Scottish botanist Robert Brown, with his manuscript published in The Botanical Register.
Members of the genus are ground-dwelling plants distinguished by small, crowded pseudobulbs, thick roots, and two to several large, corrugated or wrinkled leaves whose bases taper into a petiole-like stalk. Species range from fully evergreen to deciduous, shedding their leaves seasonally. The inflorescence is an erect, sometimes arching stem bearing numerous delicate but showy flowers crowded toward its apex. Flower colour spans white, pink, yellow, and orange. The sepals and petals are relatively narrow and spread widely, and are similar in size to each other. The labellum (lip) bears three or four spreading lobes and, in most species, a spur at its base. A key structural character distinguishing Calanthe from related genera is that the labellum is fused to the column rather than free.
The genus has a broad tropical and subtropical distribution centred on Southeast Asia, extending through the Indian subcontinent, China, Madagascar, Australia, Mexico, Central America, the West Indies, and numerous Pacific and Indian Ocean islands.
Etymology
The genus name Calanthe derives from the Ancient Greek words kallos ("beauty") and anthos ("flower"), a reference to the genus's ornamental blooms. It was first formally described in 1821 by Robert Brown, with the description published in The Botanical Register.
Distribution
Calanthe species occur across all tropical regions but are most densely concentrated in Southeast Asia. The range extends into subtropical areas including China, the Indian subcontinent, Madagascar, Australia, Mexico, Central America, the West Indies, and islands of the Pacific and Indian Oceans.
Cultivation
Calanthe orchids have been cultivated as ornamentals since the 19th century and are among the earliest orchid hybrids to have been produced. Deciduous species typically require a dry rest period after the leaves drop, while evergreen species prefer consistent moisture. They are generally grown in humus-rich, well-drained compost and prefer dappled shade.
