(1979–) A.F.Hill – Albert Frederick Hill (1889–1977) A.Fröhl. – Anton Fröhlich (1882–1969) A.Heller – Amos Arthur Heller (1867–1944) A.J.Hill – Albert Joseph Hill (1940–) A.Nelson – Aven Nelson (1859–1952) A.S.George – Alexander Segger George (1939–) A.Schüssler – Arthur Schüssler A.W. Benn. – Alfred William Bennett (1833–1902) A.W. Hill – Arthur William Hill (1875–1941) Abbot – John Abbot (1751–1840 lub 1841) Ach. – Erik Acharius (1757–1819) Adams – Johannes Michael Friedrich Adams (1780–1838) Adans. – Michel Adanson (1727–1806) Aderh. – Rudolf Aderhold (1865–1907) Afzel. – Adam Afzelius (1750–1837) Agassiz – Louis Agassiz (1807–1873) Agosti – Giuseppe Agosti (1715–1785) Ait. (Aiton) – William Aiton (1731–1793) Al. Brongn. – Alexandre Brongniart (1770–1847) Alb. – Johannes Baptista von Albertini (1769–1831) Alderw. – Cornelis Rugier Willem Karel van Alderwerelt van Rosenburgh (1863–1936) Alexander – Edward Johnston Alexander (1901–1985) All. – Carlo Allioni (1728 lub 1729–1804) Allemão – Francisco Freire Allemão (1797–1874) Allesch.