''Clymenia'' is a small 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 t ...

s in the family

Rutaceae The Rutaceae is a family, commonly known as the rueRUTACEAE
in BoDD – Botanical Der ...

with two species. The genus is often included in ''

Citrus ''Citrus'' is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is native to ...

''.

Description

''Clymenia'' forms a shrub or small tree, free of spines. Leaves feature a short, narrow petiole, which sets them apart from most other citrus, especially the papedas native to the same general area. ''Clymenia'' fruits are a small hesperidium, very similar to a citrus fruit. Sweet and lemony in flavor, the tangerine-sized fruits are highly segmented, with yellow pulp, and a leathery rind, similar to a true citrus fruit. They contain a large number of polyembryonic seeds. The fruit are eaten by the Bismarck islanders, who call it ''a-mulis'' ( Namatanai). Native to a handful of locations on

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

and nearby islets, including New Ireland,

New Britain New Britain ( tpi, Niu Briten) is the largest island in the Bismarck Archipelago, part of the Islands Region of Papua New Guinea. It is separated from New Guinea by a northwest corner of the Solomon Sea (or with an island hop of Umboi the D ...

and the

Admiralty Islands The Admiralty Islands are an archipelago group of 18 islands in the Bismarck Archipelago, to the north of New Guinea in the South Pacific Ocean. These are also sometimes called the Manus Islands, after the largest island. These rainforest-co ...

, ''Clymenia'' is far more tropical than other citrus, and even in subtropical parts of the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

, it can only be grown in a greenhouse. Specimens thrived in greenhouses in

Riverside, California Riverside is a city in and the county seat of Riverside County, California, United States, in the Inland Empire metropolitan area. It is named for its location beside the Santa Ana River. It is the most populous city in the Inland Empire an ...

, but perished when planted out in the arid climate. They are locally cultivated in indigenous villages, but have never been commercially cultivated.

Taxonomy

Cultivated locally for its sweet fruits on a handful of southwestern

Pacific islands Collectively called the Pacific Islands, the islands in the Pacific Ocean are further categorized into three major island groups: Melanesia, Micronesia, and Polynesia. Depending on the context, the term ''Pacific Islands'' may refer to one of se ...

, ''Clymenia'' was originally considered an obscure

citrus ''Citrus'' is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is native to ...

hybrid. Botanist Tyôzaburô Tanaka noted that ''Clymenia'' would hybridize with a few other citrus plants (notably

kumquat Kumquats (; zh, 金桔), or cumquats in Australian English, are a group of small fruit-bearing trees in the flowering plant family Rutaceae. Their taxonomy is disputed. They were previously classified as forming the now-historical genus ''For ...

s), but otherwise was generally different from other citrus in many aspects of its appearance. Botanist

Walter Tennyson Swingle Walter Tennyson Swingle (January 8, 1871 – January 19, 1952) was an American agricultural botanist who contributed greatly to the classification and taxonomy of citrus. Biography Swingle was born in Canaan, Pennsylvania, and moved with his ...

proposed moving ''Clymenia'' out of ''Citrus'', circumscribing the genus in 1939, naming it after a figure from Greek mythology, Clymene, an Orchomenian princess who was the mother of

Atalanta Atalanta (; grc-gre, Ἀταλάντη, Atalantē) meaning "equal in weight", is a heroine in Greek mythology. There are two versions of the huntress Atalanta: one from Arcadia, whose parents were Iasus and Clymene and who is primarily kno ...

. Swingle assumed that ''Clymenia'' and citrus evolved from a single common ancestor. In 2000, Berhow suggested that a close relationship existed between ''Clymenia'' and kumquats and that it might be a

Citrofortunella Citrofortunella are a large group of commercial hybrids that cross the kumquat with other citrus. In the system of citrus taxonomy established by Swingle, kumquats were placed in a different genus, '' Fortunella'', from ''Citrus'', which included ...

, a kumquat hybrid with another citrus. Recent genomic analysis has shed new light on the phylogeny of ''Clemenia'', potentially clarifying questions of its taxonomy. ''Clymenia polyandra'' was found to be completely

homozygous Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism. Mo ...

, proving it to be a distinct species and not a kumquat hybrid. ''Clymenia'' clusters within the genus ''Citrus'' in a clade with the Australian and New Guinean limes, which though formerly placed in genera ''Eremocitrus'' and ''Microcitrus'' are now considered members of ''Citrus''. Because excluding ''Clymenia'' would make ''Citrus''

paraphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In ...

, the ''Clymenia'' species may likewise belong in ''Citrus'', with ''Clymenia'' relegated to the status of a

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between ...

. It is included in ''Citrus'' in a 2021 classification of the family

Rutaceae The Rutaceae is a family, commonly known as the rueRUTACEAE
in BoDD – Botanical Der ...

Species

Species included in the genus:Benjamin C. Stone (1985). "New and noteworthy palotropical species of Rutaceae", ''Proceedings of The Academy of Natural Sciences of Philadelphia'', vol. 137, pp. 213-228 *''

Clymenia platypoda ''Clymenia'' may refer to: * ''Clymenia'' (ammonite), an ammonite genus in the family Clymeniidae * ''Clymenia'' (plant), a flowering plant genus in the family Rutaceae {{genus disambiguation ...

'' B.C.Stone *''

Clymenia polyandra ''Clymenia'' may refer to: * ''Clymenia'' (ammonite), an ammonite genus in the family Clymeniidae * ''Clymenia'' (plant), a flowering plant genus in the family Rutaceae {{genus disambiguation ...

'' (Tanaka) Swingle

References

External links

Pictures of Clymenia
in Papua New Guinea.

{{Taxonbar, from=Q5137103 Aurantioideae Aurantioideae genera Edible fruits