[3][4] He also translated the German language encyclopedia Grosse Bilderlexikon der Pflanzen, which was published under the title Tanums store blomsterbok og botaniske billedleksikon by the publishing house Tanum in 1970.
It was titled Ville planter i Norge ("Wild Plants in Norway"), and was reprinted in 1993.
[7][8] Although he preferred copyediting over writing, Wischmann wrote more than 60 articles for botanical journals in Scandinavia.
[2][9] Wischmann wrote more than 45,000 herbarium sheets and 21,000 checklists, which record more than half a million plant discoveries.
[9] On 7 November 2003, he was decorated as a Knight, First Class of the Order of St. Olav for his work within Norwegian botanics.