Education
After having finished the publication of Flora Danica, he issued Nomenclator Floræ Danicæ in 1887 - a volume indexing all planches in Flora Danica alphabetically, systematically and chronologically.
After having finished the publication of Flora Danica, he issued Nomenclator Floræ Danicæ in 1887 - a volume indexing all planches in Flora Danica alphabetically, systematically and chronologically.
He held the post of Librarian at the Botanical library of the University of Copenhagen from 1851 to 1858. He began editing the in 1858, and was its last editors Together with Japetus Steenstrup, Johan Lange was the publisher of fasc.
44 (1858).
Thereafter, he edited alone fasc. 45-51 (1861-1883) and Supplement vols 2-3 (1865-1874), in total 600 plates. He travelled throughout Europe, completing extensive studies on the flora of Denmark, Greenland and other European countries, especially Spain.
(Willkomm & Lange, Prodromus Florae Hispanicae, 1861-1880).
He expanded on the classification developed by Linnaeus, writing Plantenavne og navngivningsregler (Plant-names and rules for name-giving) which was influential in developing the Code of Botanical Nomenclature, the system in use today. Charles Darwin borrowed a book written by Lange, which he failed to return in a timely manner as mentioned by Darwin in his correspondence.