''Shizhenia'' is a genus of flowering plants in the family Orchidaceae. Its only species is ''Shizhenia pinguicula'', native to south-east China (north-east Zhejiang).

Description

''Shizhenia'' grows from a ovoid shaped tuber. It has a single stem leaf, situated near the base of the stem. The inflorescence consists of a single relatively large flower, rose-red to purple in colour, with a three-lobed lip (labellum). The upper sepal and the lateral

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

s are grouped to form a hood. The flower has a conical spur, longer than the lip. There are two stigmas that extend under the short rostellum.

Taxonomy

The species was first described in 1878 as ''Gymnadenia pinguicula''. It was later transferred again to '' Habenaria'' and then '' Amitostigma''. A

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study in 2014, found that species of ''Amitostigma'', ''Neottianthe'' and ''

Ponerorchis ''Ponerorchis'' is a genus of Asian terrestrial tuberous orchids (family Orchidaceae). It is native to temperate Eurasia, from Poland to Japan, to the north of the Indian subcontinent and to northern Indochina. They can be found in evergreen for ...

'' were mixed together in a single

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

, making none of the three genera

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

as then

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every polyg ...

. ''Amitostigma'' and ''Neottianthe'' were subsumed into ''Ponerorchis'', with ''Amitostigma pinguicula'' becoming ''Ponerorchis pinguicula''. Later studies suggested that ''Ponerorchis pinguicula'' lay outside the main clade consisting of ''

Hemipilia ''Hemipilia'' is a genus of plants in the family Orchidaceae. It is native to China, the Himalayas and Southeast Asia. Species # '' Hemipilia calophylla'' C.S.P.Parish & Rchb.f. - Yunnan, Myanmar, Thailand, Vietnam # '' Hemipilia cordifolia'' ...

'', ''Ponerorchis'', '' Sirindhornia'', and ''

Tsaiorchis ''Tsaiorchis'' is a genus of flowering plants in the family Orchidaceae. Taxonomy ''Tsaiorchis'' is placed in the orchid subfamily Orchidoideae, tribe Orchideae, subtribe Orchidineae. The relationship between ''Tsaiorchis'' and the rest of the s ...

'', and a new genus, ''Shizhenia'', was created for it. After some adjustment of the generic boundaries, the five genera were related as shown in the following cladogram. All are placed in subtribe Orchidinae, tribe Orchideae, subfamily Orchidoideae.

References

{{Taxonbar, from1=Q50821085, from2=Q51468445, from3=Q43372414, from4=Q15500063, from5=Q51528766 Orchideae Flora of Southeast China Monotypic Orchidoideae genera Orchideae genera