Aceraceae (maples) and Arecaceae (palms).

Acledra Signoret 1864 (pentatomid bug), Clerada Sign. 1862 (lygaeid bug), Eldarca Sign. 1864 (coreid bug), Erlacda Sign. 1864 (rhyparochromid bug), Racelda Sign. 1863 (reduviid bug), and Dalcera Sign. 1864 (coreid bug; named changed to Dersagrena Kirkaldy 1904 because it was a junior synonym of the moth Dalcera Herrich-Schäffer, 1854). Signoret does not give etymologies for these names. [See Faúndez and Verdejo, 2009, Zootaxa 2147: 49-58.]

Adajinoperus Serov & Wilson, 1999 and Pseudojanira Barnard, 1925 (Pseudojanirid isopods)

Aetapcus Scott, 1936 (prowfish), named after Pataecus Richardson, 1844 (Red Indian fish). The latter is named after Pataikos, a Phoenician deity often used as a figurehead on ships' prows. The former was originally considered a subgenus of Pataecus.

Albidella Pichon named after Baldellia Parl. (both monocot forbs)

Albizia Durazz. 1772 and Balizia Barneby &. Grimes 1996 (mimosid trees)

Alchemilla and Lachemilla (both lady's mantles)

Alsomitra L. and Siolmatra (cucurbits) Alsomitra is the original.

Annesijoa, named after Joannesia (both euphorbs)

Aristida L. and Sartidia (both reeds)

Arixenia Jordan, 1909 and Xeniaria Maa, 1974 (earwigs)

Aterigena Bolzern, Haenggi & Burckhardt 2010 and Eratigena Bolzern, Burckhardt & Haenggi 2013 (spiders) were moved from and anagrammed from Tegenaria Latreille, 1804.

Behuria Cham. named after Huberia DC. (both Melatomataceae). Some consider Behuria a junior synonym.

Belotelson Packard, 1886 and Lobetelson Schram, 2006 (both Carboniferous crustaceans). The latter, in addition to being an anagram of the former, refers to "the lobate form of the uropodal rami." [Zoosystema 28:282]

Bombacaceae (kapok) and Cabombaceae (water plant). The type genera are Bombax and Cabomba, so the anagram was unintentional.

Buckollia (Apocynaceae) derived from Bullockia (Rubiaceae).

Carcinus Leach 1814 (crab) and Cicarnus Karasawa & Fudouji 2000 (Paleogene crab)

Chironia L., 1753 and Ornichia Klak., 1986 (both Gentianaceae)

Coeloptera Turner, 1945 (genus of moth) and Coleoptera (beetle order)

Conilera, Lironeca, Nerocila, Olencira and Rocinela Leach, 1818 (isopods) All anagrams of Caroline, W.E. Leach's wife. (Lironeca was later rejected in favor of Livoneca Leach 1818.) Others later added Renocila Miers, 1880, Creniola Bruce, 1987, Norileca Bruce, 1990. Anilocra and Cirolana Leach 1818, and later Alcirona Hansen, 1890, Lanocira Hansen, 1890, and Orcilana Nierstrasz, 1931 are anagrams of Carolina, Leach's mistress. (Orcilana is a junior synonym of Argathona Stebbing, 1905.)

Cydonia and Docynia (quinces)

Dacelo Leach, 1815 (kingfisher) and Lacedo (pulchella) (kingfisher) Both named after Alcedo Linnaeus 1758 (another kingfisher)

Daption Stephens, 1826 (Pintado petrel)

Dasytes Paykull, 1798 and Sydates Casey, 1895 (both dasytid beetles). Also Adasytes Casey, 1895 and Asydates Casey, 1895.

Dawsonia (R. Brown, 1811) (a moss), and Sawdonia (early vascular plant, now extinct). I do not know the etymology of Sawdonia; the anagram may be coincidence.

Denmoza (in Argentina, genus of Cactaceae) anagram of Mendoza.

Dorsilopha Sturtevant, 1942, Lordiphosa Basden, 1961, Phloridosa Sturtevant, 1942, Psilodorha Okada, 1968, and Siphlodora Patterson & Mainland, 1944 (flies) All subgenera of, and anagrams of, Drosophila.

Dulcimanna Jell & Duncan, 1986 (fossil mayfly) "An anagram for Mrs Ilma Duncan, for her support during many years of collecting."

Ekmania Gleason and Manekia Trel. (peppers) The latter is named after the former, though the two are not closely related.

Eleotris Bloch and Schneider, 1801 and Erotelis (both sleeper fish)

Filago Linnaeus 1753, followed by Gifola, Ifloga, and Logfia Cassini, 1819, Oglifa Cassini, 1822, and finally Lifago Schweinfurth & Muschler, 1911 (all cudweeds)

Galphimia Cav., in the same family as Malpighia L. (acerola, a sub-tropical fruit)

Galypola Nieuwl., 1914 and Polygala L., both members of family Polygalaceae, the milkworts.

Guamatela Donn.-Smith, 1914 (genus of Rosaceae) anagram of Guatemala.

Kailarsenia Tirveng. and Larsenaikia Tirveng. (both Rubiaceae) The latter is named after and closely related to the former.

Kalanchoe mitejea Leblanc & Hamet, 1913 (African plant) Published jointly by French botanist Prof. Raymond Hamet and his friend Miss Alice Leblanc; the epithet is an anagram of "je t'aime" ("I love you").

Laxita and Taxila (nemeobiid butterflies)

Legenere (named for Berkeley botanist E. L. Greene)

Leymus Named after Elymus (both grasses)

Lomandra (mat-rush), and Romnalda (both Xanthorrhoeaceae).

Mesosemia and Semomesia (nemeobiid butterflies)

Mila Britton & Rose, 1922 (S. American cactus) Plants grow near the city of Lima.

Milax Gray, 1855 (mollusk) Named after Limax, another mollusk (Linaeus 1758, Martyn 1784, or Ferussac 1819)

Lanopis Signoret 1863, Nopalis Sign. 1863, Planois Sign. 1863, Sinopla Sign. 1864, Sniploa Sign. 1863 (all shield bugs). Presumably anagrams of [Maximilian] Spinola, an Italian entomologist. [See Faúndez, E., Boletín Sociedad Entomológica Aragonesa 44 (2009): 553.]

Melanthiaceae (northern monocot herbs) and Melianthaceae (African dicot trees and shrubs)

Momedossa Hessler, 1970 (Isopoda: Desmosomatidae) Anagram of Desmosoma Sars, 1864.

Nessiteras rhombopteryx (Loch Ness monster) Coined by naturalist Sir Peter Scott [in a letter to Nature, 1/15/1979]. Literally, it means "Ness monster with rhomboidal fin". Nicholas Fairbairn noted that it is also an anagram for "Monster hoax by Sir Peter S." Dr. Robert Rines, co-author of the name and obtainer of two possible underwater photographs of Nessie, shot back with his own anagram: "Yes, both pix are Monsters R."

Norysca (Clusiaceae) anagram from the related Hypericum ascyron, great Saint John's wort.

Ocinara Walker, 1856 (bombycid moth), from which the genus Racinoa Bouyer, 2008 was split.

Paeonia sect. Onaepia Lindl., 1839 (peony)

Palaechthon Simpson, Palenochtha Simpson, and Talpohenach Kay and Cartmill, 1977 (all plesiadapiforms, fossil stem-group primates) Palaechthon means "ancient native." George Gaylord Simpson created a meaningless anagram to name its relative Palenochtha. Kay and Cartmill's names for a third relative, besides being another anagram, is Welsh for "fragment of an ancient lineage."

Palinurus Weber, 1795 (spiny lobster), Linuparus (spiny lobster), Panilurus (rock lobster), and Palurinus (prawn) In Roman mythology, Palinurus was Aeneas's helmsman.

Platyura Meigen, 1803, Lapyruta, Laurypta, Lutarpya, Lyprauta, Plautyra, Pyratula, Pyrtaula, Ralytupa, Rutylapa, Rypatula, Taulyrpa, Truplaya, Tylparua, Urytalpa (predatory fungus gnats) F.W. Edwards introduced the anagram names as subgenera of Platyura, most in 1929; he added Lyprauta in 1931 and Plautyra in 1941. They are now treated as genera.

Polylepta lyptolape Blagoderov, 1998 (fungus gnat)

Pseudorhabdosynochus justinei Zeng & Yang, 2007 and P. enitsuji Neifar & Euzet, 2007 (diplectanid platyhelminths) Both teams, at the same time, wanted to name a new species after parasitologist Jean-Lou Justine. Note that "enitsuji" is simply "justine" reversed, plus an "i".

Ptinus, Niptus, and Tipnus (Coleopt: Ptinidae)

Pycreus and Cyperus, both members of Cyperaceae.

Rabilimis mirabilis (Brady, 1868) (ostracod)

Reevesia and Veeresia (flowering plants, Sterculiaceae)

Retama raetam (Forssk.) Webb & Berthel. (legume broom)

Rhamphosternarchus Günther, 1870 and Sternarchorhamphus Eignemann & Ward, 1905 (both apteronotid fish)

Saniba sabina (Plötz, 1882) (skipper) This species was originally known as Hesperia sabina, and when it was moved to its own genus, the name suggested was Sabina sabina, but Sabina was already a genus of polychaete worm, so Mielke & Casagrande named the genus with an anagram.

Selmes (fossil mousebird) One of many fossils found in the Messel pit, a German shale quarry. Lesmesodon (a small creodont mammal) also derives part of its name from an anagram of "Messel."

Solubea Bergroth, 1891 (bug) For Oebalus Stal 1862, which was a junior homonym.

Tuctoria named after Orcuttia (both grasses)

Ubochea Baill. (1891) named after Bouchea Cham. (1790) (both Verbenaceae)

Venada advena Mabille, 1889, Venada daneva, Venada nevada (Burns, 2005) (skippers) All are native to Central America.

Zacateza named after Tacazzea (both Apocynaceae)

Ethegotherium Simpson and Hegetotherium Ameghino 1887 (South American fossil mammals, hegetotheriid notoungulates)

Many more examples could be added if including names that are no longer valid.

Agirta Baill. 1858 (spurge) Named after Tragia L. and now considered a synonym.

Alciope and Capelio (Asteraceae) The latter name was given when it was determined that Alciope was not legitimately published.

Alibertia and Ibetralia (Rubeaceae trees) The latter is a junior synonym of Kutchubaea.

Asio otus (long-eared owl) and Otus asio (eastern screech owl) The latter, however, was revised to Megascops asio in 2003.

Bartsia L. and Starbia Thouars 1806 (both Orobanchaceae) The latter is now a synonym of Alectra.

Berardia Brongn. (Asteraceae) and Diberara Baill. (Bruniaceae) The latter-named Diberara is now a synonym of Nebelia.

Beriesa Steud. (madeira vine) following Siebera J. Gay (thistle) The former is a junior synonym of Anredera.

Berteroa DC. (false madwort) and Terobera Steud. (sedge) The latter is a junior synonym of Machaerina.

Bobea A.Rich. and Obbea Hook.f. (Hawaiian Rubiaceae) The latter is a junior synonym of the former.

Bolelia Raf. (calico flower) and Lobelia L. (lobelia) Bolelia is a junior synonym of Downingia.

Bouchea Cham. and Ubochea Baill. (both Verbenaceae) The latter is synonym of the accepted Stachytarpheta.

Danthonia DC. (oatgrass) and Thonandia H.P.Linder (grass). The latter is a synonym of Rytidosperma.

Despeleza Nieuwl., derived from and now a synonym of Lespedeza Michx. (legume).

Eroeda Levyns and Oedera L. (Asteraceae) Eroeda was so named by Levyns in 1948 as an anagram of Oedera, but the name was changed because Crantz had already used it for a genus of Liliaceae three years before Linnaeus published. (And that genus is invalid because it antedates Linnaeus.) It is now a synonym of Oedera.

Galaxias Cuvier 1816 (fish) Has inspired a proposed subgenus Agalaxis and new genus Saxilaga with subgenus Lixagasa. None but Galaxias are accepted names.

Gerardia Benth., Dargeria Decne., and Graderia Benth. (all Orobanchaceae forbs). The latter two were named after the first, which is now known as Agalinis. Dargeria is now Leptorhabdos.

Gyminda (Griseb.) Sarg. (false box) and Myginda Jacq. (staff-vine) Myginda came first, but all its species are now in other genera, mostly Crossopetalum.

Hottonia L. (featherfoil) and Honottia Rchb. (marshweed) The latter is a synonym of Limnophilia.

Kanimia Gardner, a synonym of Mikania Willd. (hempvine)

Lawrencia Hook. and Wrenciala A.Gray (both Malvaceae). The latter, derived from the former, is now in Plagianthus.

Lechlera Griseb. (Iridaceae), and Relchela Steud (grass). Lechlera, from with the latter was named, is properly Solenomelus.

Letestua Lecomte and Tulestea Aubrev. & Pellegr. (chicles) The latter, named after the former, is now Synsepalum.

Lobivia (a cactus from Bolivia) (The genus is no longer in use, having been split between Echinopsis and Rebutia.)

megachiropteran / cinematographer (15 letters) and Marsipobranchiata / basiparachromatin (17 letters) - Longest well-mixed anagrams. Megachiropteran = fruit bat; Marsipobranchiata = lampreys and hagfish; basiparachromatin = part of cell nucleus.