''Phreatia listeri'', commonly known as the Christmas Island caterpillar orchid, is a plant in the

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowerin ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

and is an epiphyte with four to six flat, blunt leaves in a fan-like arrangement. A large number of tiny, greenish white flowers are arranged along a thin flowering stem. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

Christmas Island Christmas Island, officially the Territory of Christmas Island, is an Australian external territory comprising the island of the same name. It is located in the Indian Ocean, around south of Java and Sumatra and around north-west of the ...

Description

''Phreatia listeri'' is a clump-forming epiphytic herb with a short stem, thin roots and between four and six flat, blunt, dark green leaves long and about wide in a fan-like arrangement. A large number of greenish white non-resupinate flowers long and wide are arranged along a thin flowering stem long. The

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coine ...

s and petals are about long and do not spread widely. The labellum is about long and wide. Flowering occurs between September and October.

Taxonomy and naming

''Phreatia listeri'' was first formally described in 1890 by

Robert Allen Rolfe Robert Allen Rolfe (1855, Wilford, Nottinghamshire – 1921, Richmond, Surrey) was an English botanist specialising in the study of orchids. For a time he worked in the gardens at Welbeck Abbey. He entered Kew in 1879 and became second assistant. ...

who published the description in the ''

Journal of the Linnean Society, Botany The ''Botanical Journal of the Linnean Society'' is a scientific journal publishing original papers relating to the taxonomy of all plant groups and fungi, including anatomy, biosystematics, cytology, ecology, ethnobotany, electron microscopy, mor ...

''. The specific epithet (''listeri'') honours

Joseph Jackson Lister Joseph Jackson Lister FRS FRMS (11 January 1786 – 24 October 1869) was an amateur British opticist and physicist and the father of The 1st Baron Lister. Ancestry In 1705, Thomas Lister, a farmer and maltster, of Bingley, Yorkshire, Englan ...

who, with

John Maclear John Fiot Lee Pearse Maclear (27 June 1838 in Cape Town – 17 July 1907 in Niagara) was an admiral in the Royal Navy, known for his leadership in hydrography. He is best known for being commander of during the ''Challenger'' Expedition (1 ...

and the officers of H.M.S. ''Egeria'' collected the type specimen.

Distribution and habitat

Found only on Christmas Island, the orchid is common on rainforest trees.

References

{{Taxonbar, from=Q1245372 listeri Endemic flora of Christmas Island Plants described in 1890 Endemic orchids of Australia Taxa named by Robert Allen Rolfe