http://en.wikipedia.org/wiki/List_of_botanists_by_author_abbreviation
According to this reference, Carol Linnaeus should be cited as L. and
not as Linn. as many people do.
Here are some interesting examples which will help you understand the
usage of these abbreviated forms:
Bebb - Michael Schuck Bebb (1833–1895)
Becc. - Odoardo Beccari (1843–1920)
Bedd. - Richard Henry Beddome (1830–1911)
Hook. - William Jackson Hooker (1785–1865)
Hook.f. - Joseph Dalton Hooker (1817–1911)
W.Hook. - William Hooker (1779–1832)
Wight - Robert Wight (1796–1872)
W.Wight - William Franklin Wight (1874–1954)
Regards
Pankaj