Clymenia

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Rosids
Cladus: Eurosids II
Ordo: Sapindales

Familia: Rutaceae
Subfamilia: Aurantioideae
Tribus: Aurantieae
Subtribus: Citrinae
Genus: Clymenia
Species: C. polyandra
Name

Clymenia Swingle
References

J. Wash. Acad. Sci. 1938, xxviii. 533, sine descr.; et in Journ. Arn. Arb.1939, xx. 251, descr.
USDA, ARS, Germplasm Resources Information Network. Clymenia Swingle in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 08-Apr-12.

Clymenia is a small genus of flowering plants in the family Rutaceae with two species. The genus is often included in Citrus.[1][2]

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).[3][4]

Native to a handful of locations on Papua New Guinea and nearby islets, including New Ireland, New Britain and the Admiralty Islands,[5] Clymenia is far more tropical than other citrus, and even in subtropical parts of the United States, it can only be grown in a greenhouse. Specimens thrived in greenhouses in Riverside, California, but perished when planted out in the arid climate. They are locally cultivated in indigenous villages, but have never been commercially cultivated.
Taxonomy
Main article: Citrus taxonomy § Australian and New Guinean species

Cultivated locally for its sweet fruits on a handful of southwestern Pacific islands, Clymenia was originally considered an obscure citrus 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. In the 1960s, botanist Walter Tennyson Swingle proposed that Clymenia might belong to a genus of its own. Swingle assumed that Clymenia and citrus evolved from a single common ancestor. Alternatively, Berhow suggested in 2000 that a close relationship existed between Clymenia and kumquat and that it might be a Citrofortunella hybrid.[3]

More recent genomic analysis showed Clymenia to cluster 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.[6][7][8] Because excluding them would make Citrus paraphyletic, the Clymenia species may likewise belong in Citrus,[6][7] with Clymenia relegated to the status of a subgenus. It is included in Citrus in a 2021 classification of the family Rutaceae.[2] Genomic analysis also showed Clymenia polyandra to be completely homozygous, proving it to be a distinct species and not a hybrid.[8]
Species

Species included in the genus:[9][5]

Clymenia platypoda B.C.Stone
Clymenia polyandra (Tanaka) Swingle

References

Stevens, P.F. "Rutaceae Genera". Angiosperm Phylogeny Website. Missouri Botanical Garden. Retrieved 2021-09-12.
Appelhans, Marc S.; Bayly, Michael J.; Heslewood, Margaret M.; Groppo, Milton; Verboom, G. Anthony; Forster, Paul I.; Kallunki, Jacquelyn A. & Duretto, Marco F. (2021). "A new subfamily classification of the Citrus family (Rutaceae) based on six nuclear and plastid markers". Taxon. doi:10.1002/tax.12543.
Krueger, R.R.; Navarro, L. (2007), Kahn, Iqrar Ahmad (ed.), "Citrus Germplasm Resources", Citrus Genetics, Breeding and Biotechnology, CAB International, pp. 64–65, ISBN 9781845931933
Jorma Koskinen and Sylvain Jousse. "Citrus Pages / Distant Citrus relatives". free.fr.
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
Bayer, Randall J; Mabberly, David J; Morton, Cynthia; Miller, Cathy H; Sharma, Ish K; Pfiel, Bernard E; Rich, Sarah; Hitchcock, Roberta; Sykes, Steve (2009). "A molecular phylogeny of the orange subfamily (Rutaceae: Aurantioideae) using nine cpDNA sequences". American Journal of Botany. 96 (3): 668–685. doi:10.3732/ajb.0800341. PMID 21628223.
Oueslati, Amel; Ollitrault, Frederique; Baraket, Ghada; Salhi-Hannachi, Amel; Navarro, Luis; Ollitrault, Patrick (2016). "Towards a molecular taxonomic key of the Aurantioideae subfamily using chloroplastic SNP diagnostic markers of the main clades genotyped by competitive allele-specific PCR". BMC Genetics. 17 (1): 118. doi:10.1186/s12863-016-0426-x. PMC 4991024. PMID 27539067.
Andrés García Lor (2013). Organización de la diversidad genética de los cítricos (PDF) (Thesis). pp. 79, 125–128.
"Clymenia Swingle". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2021-09-19.