''Pachystoma'', commonly known as kunai orchids or 粉口兰属 (fen kou lan shu), is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of two species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s in the orchid family,

Orchidaceae 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 flowering ...

. They are

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

herbs with one or two linear,

pleated A pleat (plait in older English) is a type of fold formed by doubling fabric back upon itself and securing it in place. It is commonly used in clothing and upholstery to gather a wide piece of fabric to a narrower circumference. Pleats are cat ...

or veiny leaves and more or less drooping flowers which do not open widely, on a thin, wiry flowering stem. Species in this genus are found in

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

and subtropical

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

to Australia and islands of the southwest

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

Description

Orchids in the genus ''Pachystoma'' are deciduous, terrestrial herbs with a branching underground rhizome and one or two linear, papery, pleated or veiny leaves. A thin, wiry flowering stem bears smallish, pink drooping flowers that are hairy on the outside. 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 similar in size and shape, the

lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction * Lateral cricoarytenoid muscle * Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral co ...

sepals having a hump at their base. The labellum has three lobes, the middle lobe projecting forwards and the side lobes unusually large.

Taxonomy and naming

The genus ''Pachystoma'' was first formally described in 1825 by

Carl Ludwig Blume Charles Ludwig de Blume or Karl Ludwig von Blume (9 June 1796, Braunschweig – 3 February 1862, Leiden) was a German- Dutch botanist. He was born at Braunschweig in Germany, but studied at Leiden University and spent his professional life wor ...

and the description was published in ''Bijdragen tot de Flora van Nederlandsch Indie''. The name ''Pachystoma'' is derived from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

words ''pachys'' meaning "thick" and ''stoma'' meaning "mouth", apparently referring to a thickened

callus A callus is an area of thickened and sometimes hardened skin that forms as a response to repeated friction, pressure, or other irritation. Since repeated contact is required, calluses are most often found on the feet and hands, but they may o ...

on the labellum.

Species

As of November 2022, Plants of the World Online lists the following two species of ''Pachystoma'': *'' Pachystoma nutans'' S.C.Chen & Y.B.Luo -

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...

*'' Pachystoma pubescens'' Blume - between tropical and subtropical Asia to the southwest

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

In 1879,

Heinrich Gustav Reichenbach Heinrich Gustav Reichenbach (Dresden, 3 January 1823 – Hamburg, 6 May 1889) was a botanist and the foremost German orchidologist of the 19th century. His father Heinrich Gottlieb Ludwig Reichenbach (author of ''Icones Florae Germanicae et Helv ...

described ''Pachystoma thomsonianum'' in ''

The Gardeners' Chronicle ''The Gardeners' Chronicle'' was a British horticulture periodical. It lasted as a title in its own right for nearly 150 years and is still extant as part of the magazine '' Horticulture Week''. History Founded in 1841 by the horticulturists Jose ...

'', now known as '' Ancistrochilus thomsonianus'' (Rchb.f.) Rolfe. The specific epithet (''thomsonianus'') honours the Victorian botanist George Thomson.

References

External links

*
The Internet Orchid Species Photo Encyclopedia - Pachystoma pubescens
{{Taxonbar, from=Q3241804 Collabieae genera