monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...
genus 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
legume
A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock f ...
Wisterieae
Wisterieae is a Tribe (biology), tribe of flowering plants in the bean family Fabaceae. The tribe was first described in 1994 for the sole genus ''Wisteria'', but was greatly expanded in 2019 to include 13 genera, six of which were new. Five had ...
. Its only species is ''Endosamara racemosa'', a
liana
A liana is a long- stemmed, woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the canopy in search of direct sunlight. The word ''liana'' does not refer to a ta ...
found from South India through Indo-China to the Philippines.
Description
''Endosamara racemosa'' is a robust twining woody
vine
A vine (Latin ''vīnea'' "grapevine", "vineyard", from ''vīnum'' "wine") is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas or runners. The word ''vine'' can also refer to such stems or runners themselv ...
. The young stems are green and covered with soft hairs (pubescent); the mature stems are pale brown and hairless. The leaves are evergreen and generally have 6–12 paired leaflets plus a terminal leaflet. The leaflets are long by wide. The robust
inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
is a many-flowered terminal
panicle
A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...
, long. The individual flowers are long and have the general shape of members of the subfamily Faboideae. The standard
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 ...
is long by wide. The inner surface is pink or pinkish purple, rarely white, with a dark greenish yellow nectar guide. The wing petals are slightly longer than the keel at long by wide, with short basal claws. The keel petals are long by wide, united into a cup. Nine of the
stamen
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10
Morphology and terminology
A stamen typically consists of a stalk called the filame ...
s are fused together, the other is free; all curve upwards at the apex. The flattened seed pods are long by wide, black when dry, and have 4–5 seeds. A unique feature of the genus ''Endosamara'' within the tribe Wisterieae is that the pods split into one-seeded segments before releasing the seeds. Each seed is covered in a layer of endocarp which extends into a papery wing, long and wide.
Taxonomy
''Endosamara racemosa'' was first described by William Roxburgh in 1832 in the genus ''
Robinia
''Robinia'' is a genus of flowering plants in the family Fabaceae, tribe Robinieae, native to North America. Commonly known as locusts, they are deciduous trees and shrubs growing tall. The leaves are pinnate with 7–21 oval leaflets. The flowe ...
''. It was later placed in a number of other genera, including ''
Millettia
''Millettia'' is a genus of legume in the family Fabaceae. It consists of about 150 species, which are distributed in the tropical and subtropical regions of the world. The genus was formerly known by the name ''Pongamia'', but that name was r ...
Robert Geesink
The name Robert is an ancient Germanic given name, from Proto-Germanic "fame" and "bright" (''Hrōþiberhtaz''). Compare Old Dutch ''Robrecht'' and Old High German ''Hrodebert'' (a compound of '' Hruod'' ( non, Hróðr) "fame, glory, honou ...
established the new genus ''Endosamara'' for the species, based principally on the unique structure of the seeds, which have flat samara-like wings but are enclosed in endocarp.
''Endosamara'' is placed in the tribe
Wisterieae
Wisterieae is a Tribe (biology), tribe of flowering plants in the bean family Fabaceae. The tribe was first described in 1994 for the sole genus ''Wisteria'', but was greatly expanded in 2019 to include 13 genera, six of which were new. Five had ...
, where it forms the earliest diverging
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, ...
with the genera ''
Sarcodum
''Sarcodum'' is a genus of flowering plants in the legume family, Fabaceae. It belongs to the subfamily Faboideae, tribe Wisterieae. Its three species are twining vines growing over shrubs, and are native from southeast mainland China to the Solo ...
'' and ''
Sigmoidala
''Sigmoidala'' is a monotypic genus of flowering plants in the family Fabaceae, first established in 2019. Its only species is ''Sigmoidala kityana'', native to Myanmar, northern Thailand and Laos. It was first described by William Grant Craib i ...
''. The structure of the seeds distinguishes ''Endosamara''.
Distribution
''Endosamara racemosa'' is found from South India to the Philippines, being native to
Assam
Assam (; ) is a state in northeastern India, south of the eastern Himalayas along the Brahmaputra and Barak River valleys. Assam covers an area of . The state is bordered by Bhutan and Arunachal Pradesh to the north; Nagaland and Manipur ...
, Bangladesh,
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
, Laos,
Malaya
Malaya refers to a number of historical and current political entities related to what is currently Peninsular Malaysia in Southeast Asia:
Political entities
* British Malaya (1826–1957), a loose collection of the British colony of the Straits ...