Melicope is a genus of about 240 species of shrubs and trees in the family Rutaceae, occurring from the Hawaiian Islands across the Pacific Ocean to tropical Asia, Australia and New Zealand. Plants in the genus Melicope have simple or trifoliate leaves arranged in opposite pairs, flowers arranged in panicles, with four sepals, four petals and four or eight stamens and fruit composed of up to four follicles.
Description Plants in the genus Melicope have simple or trifoliate leaves arranged in opposite pairs, or sometimes whorled. The flowers are arranged in panicles and are bisexual or sometimes with functionally male- or female-only flowers. The flowers have four sepals, four petals and four or eight stamens. There are four, sometimes five, carpels fused at the base with fused styles, the stigma similar to the tip of the style. The fruit is composed of up to four follicles fused at the base, each with one or two seeds.
Taxonomy The genus Melicope was first formally described in 1775 by Johann Reinhold Forster and his son Georg Forster in their book Characteres Generum Plantarum and the first species they described (the type species) was Melicope ternata.
The generic name Melicope is derived from Greek words μελι (meli), meaning "honey," and κοπη (kope), meaning "a division," referring to the glands at the base of the ovary. The 2009 Takhtajan system placed the genus in the subfamily Rutoideae, tribe Zanthoxyleae. A 2021 subfamily classification of the Rutaceae, based both on a new and previous molecular phylogenetic studies, places Melicope (with an expanded circumscription) in the subfamily Zanthoxyloideae, stating that the evidence does not yet support classification to tribal level.
Evidence from 2007 onwards showed that with its traditional circumscription, Melicope was not monophyletic. The previously separated genus Platydesma of four species is nested within the genus Melicope and is sister to all Hawaiian Melicope species. And while Melicope species are usually dioecious (individual plants only bear either male or female flowers), the flowers of the former Platydesma are hermaphroditic, suggesting a rare evolutionary reversion away from dioecy in Platydesma. Molecular phylogenetic analyses also suggest that the genera Comptonella, Dutaillyea, Picrella, and possibly Dutailliopsis, all from New Caledonia, might also be nested in Melicope, although they are accepted in the 2021 classification, as is the temperate Asian genus Tetradium, which has sometimes been merged into Melicope (possibly including the tropical Euodia).Hartley (2001)
Ecology Melicopes are foodplants for various animals, mainly invertebrates. Caterpillars of the Ulysses butterfly (Papilio ulysses) are fond of M. elleryana. Caterpillars of Thyrocopa moths have been found on M. clusiifolia. The larvae of some belid weevils from the genus Proterhinus also feed on Melicope although they prefer unhealthy, dying or dead specimens. The plants of some species may not be safe for humans. The nectar of wharangi (M. ternata) is known to yield toxic honey that may kill whoever eats it.Espina-Prez & Ordetx-Ros (1983): p.35
Conservation Several of the Hawaiian species are listed as "endangered" by the Government of the United States of America, due to habitat loss and competition from invasive non-native plants. A few species are already extinct.
Species list The following is a list of species accepted by Plants of the World Online as of July 2020:
Melicope aberrans T.G.Hartley – New Guinea (N.G.) Melicope accedens (Blume) T.G.Hartley – tropical Asia Melicope acuminata (Merr.) T.G.Hartley Melicope adscendens (H.St.John & Hume) T.G.Hartley & B.C.Stone - Hawaii Melicope aequata T.G.Hartley – N.G. Melicope affinis T.G.Hartley – Queensland (Qld.) Melicope alba Lauterb. – N.G. Melicope albiflora (Rech.) T.G.Hartley – Samoa Melicope alpestris T.G.Hartley – Philippines Melicope aneura (Lauterb.) T.G.Hartley – N.G. Melicope anisata (H.Mann) T.G.Hartley & B.C.Stone mokihana – Hawaii (?) Melicope anomala (Lauterb.) T.G.Hartley – N.G. Melicope bakeri T.G.Hartley – Madagascar Melicope balankazo (H.Perrier) T.G.Hartley Melicope balansae Guillaumin – New Caledonia (N.C.) Melicope balgooyi Appelhans, W.L.Wagner & K.R.Wood – Tubuai Melicope balloui (Rock) T.G.Hartley & B.C.Stone rock pelea – Hawaii Melicope barbigera A.Gray – Hawaii Melicope belahe (Baill.) T.G.Hartley Melicope benguetensis (Elmer) T.G.Hartley Melicope blancoi T.G.Hartley – Philippines Melicope bonwickii (F.Muell.) T.G.Hartley – Java, Borneo, the Philippines, N.G., Qld. Melicope borbonica (Bory) T.G.Hartley bois de catafaille blanc – Réunion Melicope boweriana (Christoph.) T.G.Hartley – Samoa Melicope bracteata (Nadeaud) S.L.Welsh – Cook Islands, Tubuai, Society Islands Melicope brassii T.G.Hartley – N.G. Melicope broadbentiana F.M.Bailey – Qld. Melicope buennemeijeri T.G.Hartley – Sumatra Melicope burmahia (Raizada & K.Naray.) T.G.Hartley – Myanmar Melicope burttiana B.C.Stone – Solomon Islands, Santa Cruz Island Melicope buwaldae T.G.Hartley – Sumatra Melicope calycina T.G.Hartley – Lesser Sunda Islands Melicope capillacea (Gillespie) A.C.Sm. – Fiji Melicope carrii T.G.Hartley – N.G. Melicope celebica T.G.Hartley – Sulawesi Melicope chapelieri (Baill.) T.G.Hartley – Mauritius Melicope christophersenii (H.St.John) T.G.Hartley & B.C.Stone – Hawaii Melicope chunii (Merr.) T.G.Hartley – Hainan Melicope cinerea A.Gray – Hawaii Melicope clemensiae T.G.Hartley – Borneo Melicope clusiifolia (A.Gray) T.G.Hartley & B.C.Stone – Hawaii Melicope conjuga T.G.Hartley – N.G. to Bismarck Archipelago Melicope contermina C.Moore & F.Muell. – Lord Howe Island Melicope coodeana T.G.Hartley – Réunion Melicope corneri T.G.Hartley – Peninsula Malaysia Melicope cornuta (Hillebr.) Appelhans, K.R.Wood & W.L.Wagner – Hawaii Melicope crassifolia (Merr.) T.G.Hartley – Vietnam Melicope crassiramis (K.Schum.) T.G.Hartley Melicope cravenii T.G.Hartley – N.G. Melicope crispula (Merr. & L.M.Perry) T.G.Hartley Melicope cruciata (A.Heller) T.G.Hartley & B.C.Stone cross-bearing pelea (extinct) – Hawaii Melicope cucullata (Gillespie) A.C.Sm. – Fiji Melicope degeneri (B.C.Stone) T.G.Hartley & B.C.Stone – Hawaii Melicope denhamii (Seem.) T.G.Hartley – N.G., Vanuatu, Santa Cruz Island Melicope dicksoniana T.G.Hartley – N.G. Melicope discolor (Baker) T.G.Hartley Melicope doormani-montis (Lauterb.) T.G.Hartley Melicope dubia (Merr.) T.G.Hartley Melicope durifolia (K.Schum.) T.G.Hartley – N.G. Melicope elleryana (F.Muell.) T.G.Hartley – N.G., Solomon Islands, Santa Cruz Island, Qld. Melicope elliptica A.Gray – Hawaii Melicope eriophylla (Merr. & L.M.Perry) T.G.Hartley Melicope erromangensis T.G.Hartley – Vanuatu Melicope euneura (Miq.) T.G.Hartley Melicope evanensis (A.C.Sm.) A.C.Sm. – Fiji Melicope exuta T.G.Hartley – N.G. Melicope fatraina (H.Perrier) T.G.Hartley Melicope fatuhivensis (F.Br.) T.G.Hartley & B.C.Stone – Marquesas Islands Melicope feddei (H.Lév.) T.G.Hartley & B.C.Stone – Hawaii Melicope fellii T.G.Hartley – Qld. Melicope flaviflora A.C.Sm. – Fiji Melicope floribunda (Baker) T.G.Hartley Melicope forbesii (Baker f.) T.G.Hartley – Santa Cruz Island Melicope frutescens (Blanco) Appelhans & J.Wen Melicope fulva (Guillaumin) B.C.Stone – N.C. Melicope glabella T.G.Hartley – Philippines Melicope glaberrima Guillaumin – N.C. Melicope glabra (Blume) T.G.Hartley – Malaysia, Andaman and Nicobar Islands Melicope glomerata (Craib) T.G.Hartley – Mainland Southeast Asia Melicope goilalensis T.G.Hartley – N.G. Melicope grisea (Planch.) T.G.Hartley – Bonin Islands to Volcano Islands Melicope haleakalae (B.C.Stone) T.G.Hartley & B.C.Stone Maui ruta tree (extinct) – Hawaii Melicope haupuensis (H.St.John) T.G.Hartley & B.C.Stone – Hawaii Melicope hawaiensis (Wawra) T.G.Hartley & B.C.Stone – Hawaii Melicope hayesii T.G.Hartley – Qld., New South Wales (N.S.W.) Melicope hiepkoi T.G.Hartley – N.G. Melicope hiiakae (B.C.Stone) T.G.Hartley & B.C.Stone – Hawaii Melicope hivaoaensis J.Florence – Marquesas Melicope homeophylla A.C.Sm. – Fiji Melicope hookeri T.G.Hartley Melicope hosakae (H.St.John) W.L.Wagner & R.K.Shannon – Hawaii Melicope idiocarpa T.G.Hartley – Sulawesi Melicope improvisa T.G.Hartley – N.G. Melicope incana T.G.Hartley – Sumatra, Borneo, Sulawesi Melicope indica Wight Melicope inopinata J.Florence – Marquesas Melicope irifica (Coode) T.G.Hartley – Réunion Melicope jonesii T.G.Hartley – Qld. Melicope jugosa T.G.Hartley – Borneo Melicope kaalaensis (H.St.John) T.G.Hartley & B.C.Stone – Hawaii Melicope kainantuensis T.G.Hartley – N.G. Melicope kavaiensis (H.Mann) T.G.Hartley & B.C.Stone – Hawaii Melicope kjellbergii T.G.Hartley – Sulawesi Melicope knudsenii (Hillebr.) T.G.Hartley & B.C.Stone Knudsen's melicope – Hawaii Melicope kostermansii T.G.Hartley – Maluku Islands to N.G. Melicope laevis T.G.Hartley – Vanuatu Melicope lamii Lauterb. – N.G. Melicope lasioneura (Baill.) Baill. ex Guillaumin Melicope latifolia (DC.) T.G.Hartley – Malaysia, Lesser Sunda Island, Myanmar, Samoa, Santa Cruz Island Melicope lauterbachii T.G.Hartley Melicope laxa (Elmer)T.G.Hartley Melicope leptococca Guillaumin – N.C. Melicope littoralis (Endl.) T.G.Hartley ex P.S.Green – Norfolk Island Melicope lobocarpa (F.Muell.) T.G.Hartley Melicope longior T.G.Hartley – Bismarck Archipelago Melicope lucida (A.Gray) A.C.Sm. – Pacific Islands Melicope lunu-ankenda (Gaertn.) T.G.Hartley – Tibet, tropical Asia Melicope lydgatei (Hillebr.) T.G.Hartley & B.C.Stone - Hawaii Melicope macgregorii T.G.Hartley – N.G. Melicope macrocarpa (King) T.G.Hartley – Malaysia Melicope macrophylla Merr. & L.M.Perry – N.G. Melicope macropus (Hillebr.) T.G.Hartley & B.C.Stone – Hawaii Melicope madagascariensis (Baker) T.G.Hartley – Madagascar Melicope magnifolia (Baill.) T.G.Hartley Melicope makahae (B.C.Stone) T.G.Hartley & B.C.Stone – Hawaii Melicope maliliensis T.G.Hartley – Sulawesi Melicope margaretae (F.Br.) T.G.Hartley – Tuamotus Melicope maxii T.G.Hartley – Sulawesi Melicope megastigma T.G.Hartley – Maluku Islands Melicope micrococca (F.Muell.) T.G.Hartley white euodia – Qld., N.S.W. Melicope mindorensis T.G.Hartley – Philippines Melicope molokaiensis (Hillebr.) T.G.Hartley & B.C.Stone – Hawaii Melicope moluccana T.G.Hartley – Maluku Islands Melicope montana Baker f. – N.C. Melicope monticola T.G.Hartley Melicope mucronata Merr. & L.M.Perry – N.G. Melicope mucronulata (H.St.John) T.G.Hartley & B.C.Stone – Hawaii Melicope munroi (H.St.John) T.G.Hartley & B.C.Stone – Hawaii Melicope nealae (B.C.Stone) T.G.Hartley & B.C.Stone – Hawaii Melicope neglecta T.G.Hartley – Java to Lesser Sunda Islands Melicope nishimurae (Koidz.) T.Yamaz. – Bonin Islands Melicope novoguineensis Valeton – N.G. Melicope nubicola T.G.Hartley – Solomon Islands Melicope nukuhivensis (F.Br.) T.G.Hartley & B.C.Stone – Marquesas Melicope oahuensis (H.Lév.) T.G.Hartley & B.C.Stone – Hawaii Melicope oblanceolata T.G.Hartley – N.G. Melicope obovata (H.St.John) T.G.Hartley & B.C.Stone obovate melicope (extinct) – Hawaii Melicope obscura (Cordem.) T.G.Hartley – Réunion Melicope obtusifolia (DC.) T.G.Hartley gros catafaille – Mauritius Melicope oppenheimeri K.R.Wood, Appelhans & W.L.Wagner Melicope orbicularis (Hillebr.) T.G.Hartley & B.C.Stone orbicular pelea – Hawaii Melicope ovalis (H.St.John) T.G.Hartley & B.C.Stone wild pelea – Hawaii Melicope ovata (H.St.John & E.P.Hume) T.G.Hartley & B.C.Stone – Hawaii Melicope pachyphylla (King) T.G.Hartley – Malaysia Melicope pachypoda (Lauterb.) T.G.Hartley Melicope pahangensis T.G.Hartley – Laos Melicope palawensis (Lauterb.) T.G.Hartley – Philippines Melicope pallida (Hillebr.) T.G.Hartley & B.C.Stone – Hawaii Melicope paniculata (H.St.John) T.G.Hartley & B.C.Stone Lihue ruta tree – Hawaii Melicope papuana (Lauterb.) Lauterb. – N.G.