Danish botanist. Oersted worked as a teacher in Copenhagen from 1839-1844 before making a trip to the West Indies and Central America in 1845-1848. Staying six weeks in Jamaica he collected plants alongside the Scots Gilbert McNab and James Macfadyen and ascended the Blue Mountain Peak. He also collected extensively in Nicaragua and Costa Rica, building up such an expertise in the region that F.W. Pennel in 1946 called him "the most important botanist of Central America". Returning to Europe Oersted took up work as a lecturer in botany at the University of Copenhagen, which granted him a PhD in 1854. He was later appointed professor. He published many papers on his botanical findings in Central America and the West Indies, being especially interested in the Acanthaceae and Fagaceae families. His major work L'Amérique Centrale was published in 1863. He also wrote articles on Danish and arctic nematodes, marine algae and plant-parasitic fungi. Plant taxa named after him include the orchid genus Oerstedella Reichenbach f.

Sources:
F.W. Pennel, "Historical Sketch", in F. Verdoorn, 1945, Plants and Plant Science in Latin America: 46
G. Sayre, 1975, "Cryptogamae Exsiccatae: an annotated bibliography of exsiccatae of algae, lichens, hepaticae, and music. V. Unpublished Exsiccatae: I. Collectors", Memoirs of the New York Botanical Garden, 19(3): 375
W. Stearn, 1965, Journal of the Arnold Arboretum, 46: 268.