Sarcochilus, commonly known as butterfly orchids or fairy bells, is a genus of approximately twenty species of flowering plants in the orchid family Orchidaceae, placed within the order Asparagales. The genus was first formally described in 1810 by the Scottish botanist Robert Brown in his landmark work Prodromus Florae Novae Hollandiae et Insulae Van Diemen, the foundational flora of Australia.
Plants in the genus are epiphytic or lithophytic monopodial herbs — meaning they grow on trees or rocks and extend from a single upright growing point. They have fibrous stems and relatively broad leaves folded lengthwise and arranged in two distinct rows. The flowers are fragrant and resupinate (twisted so the lip faces downward), borne along unbranched stems, each on a short thin stalk. Sepals and petals are free from one another and broadly similar in appearance, though petals are typically smaller than sepals. The labellum is hinged to the column and bears three lobes: the two side lobes are relatively large and often curve inward, while the structure of the middle lobe varies between species.
The genus contains roughly 27 recognised species according to GBIF, with Plants of the World Online recognising about twenty as of 2023. Most species are endemic to Australia, with a smaller number extending to New Guinea and New Caledonia. Molecular phylogenetic studies have shown the genus to be non-monophyletic, suggesting its circumscription may be revised in future treatments.
Etymology
The genus name Sarcochilus is derived from the Ancient Greek words sarx (σάρξ), meaning "flesh," and cheilos (χεῖλος), meaning "lip." The name alludes to the distinctively fleshy, hinged labellum that is a key morphological feature of the group.
Distribution
Most species of Sarcochilus are endemic to Australia, where they occur primarily along the eastern seaboard. A smaller number of species extend into New Guinea and New Caledonia. Within Australia the genus occupies both epiphytic habitats on trees and lithophytic habitats on rocky outcrops, particularly in moist, sheltered gullies and ranges.
Taxonomy Notes
Sarcochilus was first formally described by Robert Brown in 1810 in Prodromus Florae Novae Hollandiae et Insulae Van Diemen. The genus is placed in family Orchidaceae, order Asparagales. Molecular phylogenetic analyses have demonstrated that the genus as traditionally circumscribed is non-monophyletic, indicating that some members may be more closely related to species placed in other genera than to each other. Revised circumscriptions may be expected as studies of Australasian orchids continue.
