; Sp. Pl. [Linnaeus] 1: 392 (1753)
Distribution: Europe (9), Asia, esp. China (ca. 560), Himalayas and montane Malesia, esp. New Guinea (174), Australia (1), North America (ca. 25); Russia (S-Siberia, Far East) and Caucasus (ca. 20). Following molecular results, the genus is taken in a broad sense, including Ledum, Menziesia and others.
= Anthocoma K.Koch; Hort. Dendrol. 338 (1853)
= Anthodendron Rchb.; Moessl. Handb. 1: p. 40: 244, 308 (1827)
= Azalea L.; Sp. Pl. [Linnaeus] 1: 150 (1753), nom. rej.
= Azaleastrum Rydb.; Mem. New York Bot. Gard. 1: 297 (1900)
= Biltia Small; Fl. S.E. U.S. [Small] 884 (1903)
= Candollea Baumg.; Cat. Hort. Bollw., s. p. (1810), nom. illeg.
= Chamaecistus Regel; Gartenflora 60 (1874)
= Chamaerhododendron Mill.; Gard. Dict. Abr., ed. 4 (1754)
= Diplarche Hook.f. & Thomson; Hooker´s J. Bot. Kew Gard. Misc. 6: 382. t. 11 (1854)
= Dulia Adans.; Fam. Pl. [Adanson] 2: 165 (1763)
= Haustrum Noronha; Verh. Batav. Genootsch. Kunst. 5(4): 2 (1790), nomen
= Hochenwartia Crantz; Inst. Rei Herb. 2: 468 (1766)
= Hymenanthes Blume; Bijdr. Fl. Ned. Ind. 862 (1826)
= Iposues Raf.; Autik. Bot. 186 (1840)
= Ledum Ruppius ex L.; Sp. Pl. [Linnaeus] 1: 391 (1753)
= Loiseleria Rchb.; Fl. Germ. Excurs. 1: 416 (1831)
= Menziesia Sm.; Pl. Icon. Ined. I. 56 (1791)
= Osmothamnus DC.; Prodr. [A.P. de Candolle] 7: 715 (1839)
= Plinthochroma Dulac; Fl. Hautes-Pyrénées 419 (1867)
= Rhodora L.; Sp. Pl. [Linnaeus], ed. 2: 561 (1763)
= Rhodothamnus Lindl. & Paxton; Paxton´s Fl. Gard. 1: t. 22 (1850), nom. illeg.
= Stemotis Raf.; Sylva Tellur. 152 (1838)
= Theis Salisb. ex DC.; Prodr. [A.P. de Candolle] 7: 715 (1835)
= Theis Salisb. ex DC.; Prodr. [A.P. de Candolle] 7: 715 (1839), nom. inval.
= Therorhodion (Maxim.) Small; N. Amer. Fl. 29: 45 (1914)
= Tsusiophyllum Maxim.; Mém. Acad. Imp. Sci. St.-Pétersbourg, Sér. 7, 16(9): 12 (1871)
= Tsutsusi Adans.; Fam. Pl. [Adanson] 2: 164 (1763)
= Vireya Blume; Bijdr. Fl. Ned. Ind. 854 (1826)
= Waldemaria Klotzsch; Bot. Ergebn. Reise Waldemar [Klotzsch & Garcke] 99 (1862)
= xAzaleodendron Rodigas; Gard. Chron., Ser. 3, 13: 665 (1893)
= xLedodendron F.de Vos; Quart. Bull. Amer. Rhododendron Soc. 16: 272 (1962)
= xRhodazalea Anon.; J. Soc. Natl. Hort. France, Sér. 4, 9: 328 (1908)