''Pachystoma nutans'', is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of 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 flowering ...

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

. 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 elsew ...

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 C. Wells, Joh ...

. It was first described by

Sing Chi Chen Singing is the act of creating musical sounds with the voice. A person who sings is called a singer, artist or vocalist (in jazz and/or popular music). Singers perform music (arias, recitatives, songs, etc.) that can be sung with or without ...

and

Yi Bo Luo Yi or YI may refer to: Philosophic Principle * Yì (义; 義, righteousness, justice) among the 三綱五常 Ethnic groups * Dongyi, the Eastern Yi, or Tung-yi (Chinese: , ''Yí''), ancient peoples who lived east of the Zhongguo in ancient C ...

in 2002. The type specimen of ''Pachystoma nutans'' was previously overlooked among unidentified ''Eulophia'' species at the Royal Botanic Garden herbarium in

Edinburgh Edinburgh ( ; gd, Dùn Èideann ) is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. Historically part of the county of Midlothian (interchangeably Edinburghshire before 1921), it is located in Lothian ...

. It is only known from the type specimen, which was collected near Mong Yaw, Myanmar.

Description

The only specimen of ''P. nutans'' was described as follows: tall with an erect, glabrous stem. It has 5 membranous, nerved sheaths, also glabrous. No leaves were included with the specimen, probably due to the general absence of leaves during flowering, similar to other ''Pachystoma'' and ''Eulophia'' species. The raceme is long with 2 nodding flowers. The pedicel (botany) and ovary are long and white-pubescent. The flowers are pale cream, faintly flushed with pink, with a bright yellowish-green lip. The dorsal

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 coined b ...

is puberulous on both surfaces, elliptic-oblong, long and across, with 5 nerves. The lateral sepals are similar to the dorsal, but oblique. The petals are linear, acuminate at the apex, puberulous, long, and across, with 3 nerves. The lip is orbicular-ovate in outline, constricted slightly below the middle, forming three large lobes. ''Pachystoma nutans'' is distinguished from ''Pachystoma pubescens'' by its two-flowered inflorescence (versus many-flowered); glabrous rachis (versus more or less pilose), flowers nodding (rather than horizontally spreading), and its lip trilobed slightly below the middle (rather than above the middle).

References

{{Taxonbar, from=Q15480854 nutans Endemic flora of Myanmar Orchids of Myanmar Plants described in 2002