Micronesia is a biodiversity hotspot with an exceptionally high richness of endemic plant species, 10 times higher than that of Hawaii. The Mariana Islands form an archipelago in the northwest of the Micronesian region.
In 2012, Craig M. Costion and David H. Lorence compiled a list of Micronesian endemic plants, and assessed that the Mariana Islands had 22 endemic plant species (16 species in the southern Mariana Islands, of which 11 were isolated to Guam, and 5 species in the northern Mariana Islands). They concluded that there was an approximately 3% rate of endemism in the Mariana Islands (endemic species per km2), which is comparable to the rates in Hawaii (4%) and Tonga (2%) but lower than the 14% rate of endemism among all Micronesian islands. However, the number of known Marianas endemics has greatly expanded since then with new discoveries, taxonomic revisions, and improvements in digitized databases.
The following list includes plants that have an endemic range only within the Mariana Islands. "Mariana Islands" is defined in accordance with the World Geographical Scheme for Recording Plant Distributions (WGSRPD), level 3 code "MRN," and includes the following geopolitical territories:
Only species, subspecies, varieties, and forms that are recognized as "accepted" by the Plants of the World Online database are included in this list; synonyms are not include. Some synonyms are listed next to the accepted name if they are still in common use in recent botanical literature. Subspecies are abbreviated "subs.," varieties "var.," and forms "f." after the species name.
The following list of Marianas endemic plants was compiled based on a list generated by Plants of the World Online in May 2023. This list may not be complete and may not reflect recent changes in taxonomy. An updated list of accepted species for a geographic area can be generated on the Plants of the World Online.[1]
Plants are listed in order by approximate size of their native range, beginning with those with the most restricted native ranges.
| Image | Scientific name | Chamorro name(s) | Order | Native distribution | Conservation status | |
|---|---|---|---|---|---|---|
| Terminalia rostrata Fosberg & Falanruw[2] | Myrtales | Asuncion | ||||
| Leptecophylla mariannensis (Kaneh.) C.M.Weiller[3] | Ericales | Alamagan | ||||
| Psychotria hombroniana (Baill.) Fosberg[4] | Aplokating-palaoan | Rubiales | Psychotria hombroniana: Marianas, Caroline Islands
| |||
| Osmoxylon mariannense (Kaneh.) Fosberg & Sachet[8] | No known common name[9] | Apiales | Rota | Critically endangered (IUCN)[10] Endangered (USFWS) | ||
| Nesogenes rotensis Fosberg & D.R.Herbst[11] | No known common name[12] | Lamiales | Rota | Endangered (USFWS) | ||
| Derris mariannensis Hosok.[13] | Fabales | Rota | ||||
Psychotria rotensis Kaneh.[14]
| Gentianales | Psychotria rotensis: Marianas, Caroline Islands
| Psychotria rotensis is considered a rare plant on Guam by GPEPP (University of Guam)[16] | |||
| Croton saipanensis Hosok.[17] | Euphorbiales | Saipan | ||||
| Mucuna pacifica Hosok.[18] | Fabales | Saipan | ||||
| Phreatia ladronica Tuyama[19] | Asparagales | Saipan | ||||
| Hedyotis scabridifolia Kaneh.[20] | Gentianales | Hedyotis scabridifolia Marianas
| ||||
| Pogostemon guamensis Lorence & W.L.Wagner[23] | No known common name | Lamiales | Guam (northern limestone cliff faces)[24] | Critically endangered (preliminarily) | ||
| Tinospora homosepala Diels[25] | No known common name | Ranunculales | Guam | Endangered (USFWS) | ||
| Hedyotis megalantha Merr.[26] | Paudedo | Gentianales | Guam | Endangered (USFWS) | ||
| Eugenia bryanii Kaneh.[27] | No known common name | Myrtales | Guam | Endangered (USFWS) | ||
| Psychotria malaspinae Merr.[28] | Aplokating-palaoan | Gentianales | Guam | Endangered (USFWS) | ||
| Elatostema divaricatum (Gaudich.) Fosberg[29] | Rosales | Guam | ||||
| Elatostema stenophyllum Merr.[30] | Rosales | Guam | ||||
| Dianella saffordiana Fosberg & Sachet[31] | Asparagales | Guam | ||||
| Potamogeton marianensis Cham. & Schltdl.[32] | Alismatales | Guam | ||||
| Psychotria andersonii Fosberg[33] | Gentianales | Guam | ||||
| Digitaria gaudichaudii (Kunth) Henrard[34] | Poales | Guam | ||||
| Schleinitzia fosbergii Nevling & Niezgoda[35] | Fabales | Guam | ||||
| Allophylus holophyllus Radlk.[36] | Ericales | Guam | ||||
| Rhaphidophora guamensis P.C.Boyce[37] | Araceae | Guam | ||||
| Timonius nitidus (Bartl. ex DC.) Fern.-Vill.[38] | Gentianales | Guam | ||||
| Syzygium guamense Byng[39] | Myrtales | Guam | ||||
| Bulbophyllum raulersoniae Deloso, Paulino & Cootes[40] | Asparagales | Guam | Proposed by Deloso et al. to be listed as endangered[41] | |||
| Crepidium alamaganense (S.Kobay.) T.Yukawa[42] (synonym: Malaxis alamaganensis) | Asparagales | Northern Marianas | ||||
Peperomia mariannensis C.DC.[43]
| Piperales | Peperomia mariannensis: Marianas, Caroline Islands (Palau)
| ||||
| Dendrobium oblongimentum Hosok. & Fukuy.[45] | Asparagales | Guam (northern), Rota | ||||
| Serianthes nelsonii Merr.[46] | Håyun lågu (Guam)Trongkon guåfi (Rota) | Fabales | Guam, Rota | Endangered (USFWS) | ||
| Bulbophyllum guamense Ames[47] | Siboyas hålom tåno | Asparagales | Guam, Rota | Threatened (USFWS) | ||
| Thelypteris gretheri (W.H.Wagner) B.C.Stone[48] (synonym: Cyclosorus gretheri) | Polypodiales | Guam, Rota | ||||
| Thelypteris guamensis (Holttum) Fosberg & Sachet[49] (synonym: Cyclosorus guamensis) | Polypodiales | Guam, Rota | ||||
| Tabernaemontana rotensis (Kaneh.) B.C.Stone | International Plant Names Index">Web site: Tabernaemontana rotensis International Plant Names Index . 18 March 2023 . www.ipni.org . 18 March 2023 . https://web.archive.org/web/20230318134740/https://www.ipni.org/n/60477111-2 . live . (considered by POWO to be a synonym of the more widespread Tabernaemontana pandacaqui[50] although it was determined by USFWS, using genetic analysis, to be a distinct species.[51] | No known common name | Gentianales | Guam, Rota | Threatened (USFWS) (Tabernaemontana rotensis) | |
| Syzygium thompsonii[52] | Atoto[53] | Myrtales | Guam, Rota, Saipan | |||
| Solanum guamense Merr.[54] | Berenghenas halomtano | Solanales | Marianas | Endangered (USFWS) | ||
| Phyllanthus saffordii Merr.[55] | No known common name | Malpighiales | Marianas | Endangered (USFWS) | ||
| Hedyotis laciniata Kaneh.[56] | Gentianales | Marianas | Considered a rare plant on Guam by GPEPP (University of Guam)[57] | |||
| Claoxylon marianum Müll.Arg.[58] | Katot | Malpighiales | Marianas | Considered a rare plant on Guam by GPEPP (University of Guam)[59] | ||
| Nervilia jacksoniae Rinehart & Fosberg[60] | No known common name | Asparagales | Marianas | Threatened (USFWS) | ||
| Maesa walkeri Fosberg & Sachet[61] | No known common name | Ericales | Marianas | Threatened (USFWS) | ||
| Dendrobium guamense Ames[62] | No known common name | Asparagales | Marianas | Threatened (USFWS) | ||
| Trachoma guamense (Ames) Garay (synonym: Tuberolabium guamense)[63] | No known common name | Asparagales | Marianas | Threatened (USFWS) | ||
| Canavalia megalantha Merr.[64] | Fabales | Marianas | ||||
| Dischidia puberula Decne.[65] | Gentianales | Marianas | ||||
| Jasminum marianum DC.[66] | Banago | Lamiales | Marianas | |||
| Eugenia palumbis Merr.[67] | Agatelang | Myrtales | Marianas | |||
| Drypetes dolichocarpa Kaneh.[68] (synonym: Drypetes rotensis) | Mwelel[69] | Malpighiales | Marianas | |||
| Macaranga thompsonii Merr.[70] | Pengua | Malpighiales | Marianas | |||
| Ochrosia mariannensis A.DC.[71] | Langiti[74] | Gentianales | Marianas
| |||
| Discocalyx megacarpa Merr.[75] | Otot | Ericales | Marianas | |||
| Discocalyx ladronica Mez[76] | Ericales | Marianas | ||||
| Piper guahamense C.DC.[77] | Pupúlu aniti | Piperales | Marianas | |||
| Piper salicinum Opiz[78] | Piperales | Marianas | ||||
| Ischaemum longisetum Merr.[79] | Poales | Marianas | ||||
| Cyrtandra agrihanensis Ohba | Lamiales | Marianas | ||||
| Premna mariannarum Schauer[80] | Lamiales | Marianas | ||||
| Premna paulobarbata H.J.Lam[81] | Lamiales | Marianas | ||||
| Corchorus tiniannensis Hosok.[82] | Malvales | Marianas | ||||
| Grammatophyllum schmidtianum Schltr.[83] | Asparagales | Marianas | ||||
| Bikkia longicarpa Valeton[84] | Gentianales | Marianas | ||||
| Allophylus laetus Radlk.[85] | Sapindales | Marianas | ||||
| Tarenna sambucina var. glabra (Merr.) Fosberg & Sachet[86] | Gentianales | Marianas | ||||
| Callicarpa lamii Hosok.[87] | Lamiales | Marianas (Guam, Rota, Aguiguan, Tinian, Saipan, Alamagan, Pagan, Agrihan) | ||||
| Callicarpa candicans var. paucinervia (Merr.) Fosberg[88] | Hamlag | Lamiales | Marianas |
The following list includes plants that are native to the Marianas but have a broader native range in Micronesia or the Pacific islands. Plants with native ranges into the Asian continent are not included.
Only species or subspecies that are recognized as "accepted" by the Plants of the World Online database are included in this list (synonyms are not include). Some synonyms are listed with the accepted name if they are still in common use in recent botanical literature. This list is not complete and may not reflect recent changes in taxonomy. An updated and complete list can be generated on the Plants of the World Online.
Plants are listed roughly in order by size of their native range, beginning with plants with the most restricted native ranges.
| Image | Scientific name | Chamorro name(s) | Order | Native Distribution | Conservation status | |
|---|---|---|---|---|---|---|
| Phreatia thompsonii Ames[89] | Asparagales | Guam, Pohnape | ||||
| Meryta senfftiana Volkens[90] | Apiales | Saipan to Caroline Islands | ||||
| Phyllanthus marianus Müll.Arg.[91] | Gaogao uchan | Malpighiales | Marianas to Caroline Islands (Ulithi) | |||
| Psychotria mariana Bartl. ex DC.[92] | Aplokating | Gentianales | Marianas to Caroline Islands (Fais) | |||
| Ixora triantha Volkens[93] | Guaguat[94] | Gentianales | Marianas, Caroline Islands (Yap) | |||
| Elaeocarpus joga Merr.[95] | Yoga | Oxalidales | Marianas, Caroline Islands (Palau) | |||
| Zeuxine fritzii Schltr.[96] | Asparagales | Marianas, Caroline Islands (Palau) | ||||
| Zeuxine ovata (Gaudich.) Garay & W.Kittr.[97] | Asparagales | Marianas, Caroline Islands (Palau) | ||||
| Artocarpus mariannensis Trécul[98] | Dugdug | Rosales | Marianas to Caroline Islands (Palau) | |||
| Heritiera longipetiolata Kaneh.[99] | Ufa hålom tåno' | Malvales | Marianas to Caroline Islands (Pohnpei) | Endangered (USFWS) | ||
| Glochidion marianum Müll.Arg.[100] (synonym: Phyllanthus mariannensis;[101] WFO recognizes Phyllanthus mariannensis as an accepted species.[102]) | Chosgu[103] | Malpighiales | Glochidion marianum: Guam and Caroline IslandsPhyllanthus mariannensis: Guam | |||
| Taeniophyllum marianense Schltr.[104] | Asparagales | Marianas, Caroline Islands | ||||
| Hedyotis fruticulosa (Volkens) Merr.[105] | Gentianales | Marianas, Caroline Islands | ||||
| Ficus microcarpa var. saffordii (Merr.) Corner[106] | Rosales | Marianas, Caroline Islands | ||||
| Tephrosia mariana DC.[107] | Fabales | Marianas, Caroline Islands | ||||
| Sporobolus farinosus Hosok.[108] | Poales | Marianas, Caroline Islands | ||||
| Coelogyne guamensis Ames[109] | Asparagales | Marianas, Caroline Islands | ||||
| Thelypteris maemonensis (W.H.Wagner & Grether) B.C.Stone[110] (synonym: Cyclosorus maemonensis) | Polypodiales | Marianas, Caroline Islands | ||||
| Elatostema calcareum Merr.[111] | Tupun ayuyu | Rosales | Marianas, Caroline Islands | |||
| Xylosma nelsonii Merr.[112] | Malpighialies | Marianas, Caroline Islands | ||||
| Gymnosporia thompsonii Merr.[113] (synonym: Maytenus thompsonii) | Luluhot | Celastrales | Marianas to Caroline Islands | |||
| Aglaia mariannensis Merr.[114] | Mapuñao | Sapindales | Marianas to Caroline Islands | |||
| Melastoma malabathricum var. mariannum (Naudin) Fosberg & Sachet[115] | Gafao | Myrtales | Marianas, Caroline Islands | |||
| Sphaeropteris aramaganensis (Kaneh.) R.M.Tryon[116] | Cyatheales | South Kazan-retto to Marianas | ||||
| Digitaria mezii Kaneh.[117] | Poales | Marianas, New Guinea | ||||
| Cycas micronesica K.D.Hill[118] | Fadang | Cycadales | Marianas, Caroline Islands, Marshall Islands) | Endangered (IUCN); Threatened (USFWS) | ||
| Melochia villosissima (C.Presl) Merr.[119] | Sayåfii[120] | Malvales | Kazan-retto (Minami-Iōtō) to northwestern Pacific (Caroline Is., Marianas) | |||
| Myoporum boninense Koidz.[121] | Lamiales | Ogasawara-shoto, Marianas, New South Wales | ||||
| Ixora casei Hance[122] | Gentianales | Northwest Pacific to Gilbert Islands (Caroline Is., Gilbert Is., Marianas, Marshall Is.) | ||||
| Dendrocnide latifolia (Gaudich.) Chew[123] | Rosales | Solomon Islands to W. Pacific (Caroline Is., Marianas, New Caledonia, Solomon Is., Vanuatu) | ||||
| Freycinetia reineckei Warb.[124] | Fianiti | Pandanales | Western Pacific (Caroline Is., Marianas, Samoa, Vanuatu) | |||
| Myrtella bennigseniana (Volkens) Diels[125] | Myrtales | Marianas, Caroline Is., New Guinea | ||||
| Hernandia labyrinthica Tuyama[126] | Laurales | Marianas, New Guinea, Solomon Is. | ||||
| Medinilla medinillana (Gaudich.) Fosberg & Sachet[127] | Myrtales | Sulawesi, Maluku New Guinea, and Marianas | ||||
| Leptopetalum foetidum (G.Forst.) Neupane & N.Wikstr.[128] | Gentianales | Cook Is., Fiji, Marianas, New Caledonia, Niue, Samoa, Tonga, Tubuai Is., Vanuatu | ||||
| Vitex cofassus Reinw. ex Blume | Lamiaceae | Bismarck Archipelago, Caroline Is., Maluku, Marianas, New Guinea, Solomon Is., Sulawesi[129] | ||||
| Ficus prolixa G.Forst. | Nunu | Moraceae | Caroline Is., Cook Is., Fiji, Gilbert Is., Line Is., Marianas, Marquesas, Nauru, New Caledonia, Niue, Pitcairn Is., Samoa, Society Is., Tonga, Tuamotu, Tubuai Is., Tuvalu, Vanuatu, Wallis-Futuna Is.[130] | |||
| Eugenia reinwardtiana (Blume) DC.[131] | A'abang | Myrtales | Jawa (Kangean Island) to Pacific (Borneo, Caroline Is., Cook Is., Fiji, Hawaii, Jawa, Lesser Sunda Is., Maluku, Marianas, Marquesas, New Guinea, Niue, Pitcairn Is., Queensland, Samoa, Society Is., Tonga, Tuamotu, Tubuai Is., Vanuatu, Western Australia) | |||
| Merrilliodendron megacarpum (Hemsl.) Sleumer[132] | Icacinales | Philippines to W. Pacific (Bismarck Archipelago, Caroline Is., Marianas, New Guinea, Philippines, Santa Cruz Is., Solomon Is., Sulawesi, Vanuatu) | ||||
| Capparis spinosa subsp. cordifolia (Lam.) Fici[133] (synonym: Capparis mariana) | Brassicales | Central Malesia to western and southern Pacific (Caroline Is., Cook Is., Fiji, Lesser Sunda Is., Marianas, Marshall Is., Nauru, New Caledonia, New Guinea, Niue, Philippines, Pitcairn Is., Samoa, Society Is., Solomon Is., Tonga, Tuamotu, Tubuai Is., Vanuatu, Wallis-Futuna Is.) | ||||
| Grewia prunifolia A.Gray[134] | Malvales | Cook Is., Fiji, Marianas, New Caledonia, Niue, Samoa, Society Is., Tonga, Tuamotu, Tubuai Is., Vanuatu, Wallis-Futuna Is. | ||||
| Gynochthodes myrtifolia (synonym: Morinda umbellata var. glandulosa (Merr.) Fosberg)[135] | Gentianales | G. myrtifolia: western and southern Pacific (Caroline Is., Cook Is., Fiji, Marianas, Marquesas, New Caledonia, Niue, Pitcairn Is., Samoa, Society Is., Tonga, Tuamotu, Tubuai Is., Vanuatu, Wallis-Futuna Is.) | Considered a rare plant on Guam by GPEPP (University of Guam) (listed as Morinda umbellata)[136] | |||
| Heliotropium anomalum Hook. & Arn.[137] | Boraginales | Caroline Is., Cook Is., Hawaii, Line Is., Marianas, New Caledonia, Niue, Pitcairn Is., Society Is., Tuamotu, Tubuai Is., Wake I. | ||||
| Geniostoma rupestre var. glaberrimum (Benth.) B.J.Conn[138] | Måhlok håyu, Anasser | Gentianales | Solomon Islands to western and southern Pacific (Caroline Is., Fiji, Marianas, New Caledonia, Niue, Pitcairn Is., Samoa, Santa Cruz Is., Society Is., Tonga, Tubuai Is., Vanuatu, Wallis-Futuna Is.) | |||
| Solanum repandum G.Forst.[139] (synonym: Solanum mariannense) | Solanales | Bismarck Archipelago, Cook Is., Fiji, Marianas, Marquesas, Niue, Pitcairn Is., Society Is., Vanuatu (Solanum mariannense previously reported to be endemic to Rota)[140] | ||||
| Sphaeropteris lunulata (G.Forst.) R.M.Tryon(often listed as its synonym, Cyathea lunulata (G.Forst.) Copel.[141] | Cyatheales | Bismarck Archipelago to western Pacific (Bismarck Archipelago, Caroline Is., Fiji, Marianas, Samoa, Santa Cruz Is., Solomon Is., Sulawesi, Tonga, Vanuatu, Wallis-Futuna Is.)[142] | Cyathea lunulata (synonymous name) is considered a rare plant on Guam by GPEPP (University of Guam)[143] | |||
| Cocos nucifera L.[144] | Niyok (coconut) | Arecales | Central Malesia to SW. Pacific (Bismarck Archipelago, Maluku, New Guinea, Philippines, Queensland, Samoa, Santa Cruz Is., Solomon Is., Tonga, Vanuatu) | |||
| Bikkia tetrandra (L.f.) A.Rich.[145] | Gausali | Gentianales | New Guinea to western Pacific (Caroline Is., Fiji, Marianas, New Caledonia, New Guinea, Niue, Solomon Is., Tonga, Vanuatu, Wallis-Futuna Is.) | |||
| Polyscias macgillivrayi (Benth.) Harms[146] Synonym: Polyscias grandifolia | Pepega | Apiales | New Guinea to western Pacific (Bismarck Archipelago, Caroline Is., Gilbert Is., Marianas, New Guinea, Queensland, Santa Cruz Is., Solomon Is.) | |||
| Meiogyne cylindrocarpa (Burck) Heusden[147] | Paipai | Magnoliales | Malesia to Marianas and N. Australia (Borneo, Jawa, Marianas, New Guinea, Northern Territory, Philippines, Queensland, Vanuatu, Western Australia) | |||
| Paratrophis pendulina (Endl.) E.M.Gardner[148] (synonym: Streblus pendulinus)[149] | Rosales | E. New Guinea to E. Australia and Pacific (Caroline Is., Fiji, Hawaii, Marianas, New Caledonia, New Guinea, New South Wales, Norfolk Is., Queensland, Tubuai Is., Vanuatu) | ||||
| Psydrax odoratus subsp. odoratus[150] | Gentianales | Caroline Is., Fiji, Hawaii, Marianas, Marquesas, New Caledonia, New Guinea, Pitcairn Is., Society Is., Tonga, Tuamotu, Tubuai Is., Vanuatu[151] | ||||
| Schoenus maschalinus Roem. & Schult. | Cyperaceae | Chatham Is., Marianas, New Guinea, New South Wales, New Zealand North, New Zealand South, Philippines, Queensland, South Australia, Sumatera, Tasmania, Victoria[152] | ||||
| Tristiropsis acutangula[153] [154] (synonym, Tristiropsis obtusangula)[155] | Fai'a | Sapindales | Bismarck Archipelago, Borneo, Caroline Is., Christmas I., Jawa, Lesser Sunda Is., Maluku, Marianas, New Guinea, Philippines, Queensland, Solomon Is., Sulawesi[156] | |||
| Trichomanes atrovirens (C.Presl) Kunze | Hymenophyllaceae | Bismarck Archipelago, Caroline Is., Maluku, Nansei-shoto, New Guinea, New South Wales, Norfolk Is., Philippines, Queensland, Santa Cruz Is., Solomon Is., Sulawesi, Vanuatu[157] | ||||
| Fagraea berteroana A.Gray ex Benth.[158] | Gentianales | Papuasia to Pacific (Bismarck Archipelago, Caroline Is., Cook Is., Fiji, Gilbert Is., Marianas, Marquesas, Nauru, New Caledonia, New Guinea, Niue, Queensland, Samoa, Society Is., Solomon Is., Tonga, Tubuai Is., Vanuatu, Wallis-Futuna Is.) | ||||
| Asplenium laserpitiifolium Lam.[159] | Polypodiales | Nansei-shoto to Malesia and Pacific (Bismarck Archipelago, Caroline Is., Fiji, Kazan-retto, Lesser Sunda Is., Maluku, Marianas, Marquesas, Nansei-shoto, New Caledonia, New Guinea, Niue, Ogasawara-shoto, Philippines, Queensland, Samoa, Society Is., Solomon Is., Sulawesi, Tonga, Tubuai Is., Vanuatu, Wallis-Futuna Is.) | Considered a rare plant on Guam by GPEPP (University of Guam) | |||
| Alyxia stellata (J.R.Forst. & G.Forst.) Roem. & Schult.[160] | Gentianales | Northeast Queensland to Pacific (Caroline Is., Cook Is., Fiji, Hawaii, Marianas, Marquesas, New Caledonia, Niue, Pitcairn Is., Queensland, Samoa, Society Is., Solomon Is., Tonga, Tuamotu, Tubuai Is., Vanuatu, Wallis-Futuna Is.) | ||||
| Pandanus tectorius Parkinson[161] | Pandanales | Philippines to Pacific and eastern Australia (Bismarck Archipelago, Caroline Is., Cocos (Keeling) Is., Cook Is., Fiji, Gilbert Is., Hawaii, Jawa, Lesser Sunda Is., Line Is., Maluku, Marianas, Marquesas, Marshall Is., Nauru, New Caledonia, New Guinea, New South Wales, Niue, Philippines, Pitcairn Is., Queensland, Samoa, Santa Cruz Is., Society Is., Solomon Is., Tokelau-Manihiki, Tonga, Tuamotu, Tubuai Is., Tuvalu, Vanuatu, Wake I., Wallis-Futuna Is.) |
The following list includes select species or variants that have previously been considered endemic to the Mariana Islands, and may still be listed as such in certain publications, but are not considered to be valid species according to the Plants of the World Online database. Also included here are species that have more recently been proposed to be distinct species or subspecies, but have not yet been accepted.
| Scientific name | Chamorro name(s) | Order | Native Distribution | Conservation status | |
|---|---|---|---|---|---|
| Korthalsella species (unnamed species presented at Micronesia Terrestrial Conservation Conference)[162] | Santalales | ||||
| Zehneria guamensis (Merr.) Fosberg[163] | Ahgaga[164] | Cucurbitales | Despite its species name, it is listed as native to China South-Central, China Southeast, Marianas, Nansei-shoto, Taiwan. However, it is elsewhere described as a Marianas endemic.[165] [166] [167] | Considered a rare plant on Guam by GPEPP (University of Guam) | |
| Carallia tulasnei Baill (unplaced name)[168] | Malpighiales | Marianas | |||
| Melanolepis multiglandulosa var. glabrata (Müll.Arg.) Fosberg[169] (now considered a synonym of the more widespread Melanolepis multiglandulosa (Reinw. ex Blume) Rchb. & Zoll.) | Ålom[170] | Malpighiales | Melanolepis multiglandulosa var. glabrata (previously reported to be endemic to the Marianas)Melanolepis multiglandulosa (S. Indo-China to Nansei-shoto and NW. Pacific, including Marianas) | ||
| Ceratopteris gaudichaudii Brongn. (now considered a synonym of the pan-tropical Ceratopteris thalictroides (L.) Brongn.)[171] | Polypodiales | Ceratopteris gaudichaudii:Ceratopteris thalictroides: pan-tropical/subtropical[172] | |||
| Cerbera dilatata Markgr.[173] (now considered a synonym of Cerbera odollam Gaertn.)[174] | Chiute[175] | Gentianales | Cerbera dilatata: previously listed as a Marianas endemicCerbera odollam: South India to Pacific |