• Baisia V.A. Krassilov in V.A. Krassilov & E.V. Bugdaeva, 1982 † (uncertain)
• Banisia Walker, 1863
• Barisia Gray, 1838
• Belvisia Desvaux, 1814 accepted as Napoleonaea Palisot de Beauvois, 1804 [Family: Lecythidaceae]
• Belvisia Mirbel in Lamarck & Mirbel, 1802 [Family: Polypodiaceae]
• Brachisia Yang, Zhang & Yang, 1995
• Bradisa Gistl, 1848 accepted as Trocheta Dutrochet, 1817
• Bradysia Winnertz, 1867
• Braesia Grote & Robinson, 1869 (uncertain)
• Brainia Uvarov, 1922
• Brandisia J.D. Hooker & T. Thomson, 1864
• Branikia Havlicek, 1957 †
• Brapasia W.W.G. Moir, 1957 (uncertain)
• Brasia Strand, 1932 accepted as Beziella Enderlein, 1937
• Brasilia Buckman, 1898 † [Family: Ammonoidea (awaiting allocation)]
• Brasilia Clarke, 1913 † accepted as Chapadella Greger, 1920 † [Family: Terebratulida (awaiting allocation)]
• Brasilia Cossmann, 1918 † accepted as Buckmanina Cossmann, 1920 † [Family: Archaeogastropoda (awaiting allocation)]
• Brasilia G.M. Barroso, 1962 accepted as Calea Linnaeus, 1763 [Family: Asteraceae]
• Brassia A. Massalongo, 1860 accepted as Thelotrema Acharius, 1803 [Family: Thelotremataceae]
• Brassia R. Brown in W.T. Aiton, 1813 [Family: Orchidaceae]
• Braunsia Buckman, 1902 † (uncertain) [Family: Hildoceratidae]
• Braunsia Kriechbaumer, 1894 [Family: Braconidae]
• Braunsia Schwantes, 1928 [Family: Aizoaceae]
• Bravaisia A.P. de Candolle, 1838
• Braxilia Rafinesque, 1840 (unaccepted)
• Brazilia Clarke, 1913 † (uncertain)
• Gravisia Mez in C.F.P. Martius, 1891 accepted as Aechmea Ruiz & Pavón, 1794
• Travisia Johnston, 1840