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)

Alchemilla and Lachemilla (both lady's mantles)

Aristida L. and Sartidia (both reeds)

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

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

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

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."

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

Eratigena Bolzern, Burckhardt & Haenggi, 2013 was moved from and anagrammed from Tegenaria Latreille, 1804 (spiders)

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

Galphimia , in the same family as Malpighia (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.

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)

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

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.]

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.

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.

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)

Zacateza named after Tacazzea (both Apocynaceae)

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

Eutatus and Utaetus Ameghino (S. American fossil armadillos),

Macrauchenia and Cramauchenia Ameghino (S. American ungulates),

Toxodon and Xotodon Ameghino. (S. American fossil perissodactyls) Florentino Ameghino was an Argentinian paleontologist; the genus Florentinoameghinia (a lower Eocene mammal) was named after him, as is an Argentine paleontology journal, Ameghiniana.

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

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.