Johan Martin Christian Lange (20 March 1818 – 3 April 1898) was a prominent Danish botanist. He held the post of Librarian at the Botanical library of the University of Copenhagen from 1851 to 1858. He was Director of the Botanical Garden there from 1856 to 1876, the Reader of botany at the Danish Technical University from 1857 to 1862, and Reader of Botany at the Royal Veterinary and Agricultural University from 1858 to 1893, achieving full professor standing in 1892. He began editing the Flora Danica in 1858, and was its last editor. Together with Japetus Steenstrup, Johan Lange was the publisher of Flora Danica fasc. 44 (1858). Thereafter, he edited alone fasc. 45-51 (1861–83) and Supplement vols 2-3 (1865–74), in total 600 plates. After having finished the publication of Flora Danica,