''Clymenia'' is a small genus of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s in the family

Rutaceae The Rutaceae () is a family (biology), family, commonly known as the rueRUTACEAE
in Bo ...

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

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

''.

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 A hesperidium (: hesperidia) is a modified berry with a tough, leathery rind, as in the oranges and lemons of the genus ''Citrus''. Etymology Carl Linnaeus gave the name Hesperideæ to an order containing the genus ''Citrus'', in allusion to ...

, 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, officially the Independent State of Papua New Guinea, is an island country in Oceania that comprises the eastern half of the island of New Guinea and offshore islands in Melanesia, a region of the southwestern Pacific Ocean n ...

and nearby islets, including New Ireland,

New Britain New Britain () 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 Island, Umboi the Dampie ...

and the

Admiralty Islands The Admiralty Islands are an archipelago group of 40 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-cov ...

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

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, 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. It is named for its location beside the Santa Ana River. As of the 2020 census, the city has a population of 314,998. It is the most populous city in th ...

, 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 The Pacific islands are a group of islands in the Pacific Ocean. They 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 several ...

, ''Clymenia'' was originally considered an obscure

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

hybrid. Botanist Tyôzaburô Tanaka noted that ''Clymenia'' would hybridize with a few other citrus plants (notably kumquats), but otherwise was generally different from other citrus in many aspects of its appearance. Botanist Walter Tennyson Swingle 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 (; ) is a heroine in Greek mythology. There are two versions of the huntress Atalanta: one from Arcadia (region), Arcadia, whose parents were Iasus and Clymene (mythology), Clymene and who is primarily known from the tales of the Caly ...

. 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, 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. Mos ...

, 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 Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

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

subgenus In biology, a subgenus ( 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 the ge ...

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

Rutaceae The Rutaceae () is a family (biology), family, commonly known as the rueRUTACEAE
in Bo ...

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'' B.C.Stone *'' Clymenia polyandra'' (Tanaka) Swingle

References

External links

Pictures of Clymenia
in Papua New Guinea.

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