U.S. botanist specialising in the Araceeae family and Asian flora. The seeds of Dan Nicolson's interest in plants were sown while he was a child, for his family were nursery owners. He grew up in Shenandoah, Iowa, and with a role in the family enterprise in mind, enrolled to study business at Stanford University, gaining his MBA in 1957. During his undergraduate studies at Grinnell College he had become interested in botany and published his first article on the weeds of Iowa in 1955. While at Stanford, Nicolson assisted in the Dudley Herbarium and thereafter decided to enter into full time study of botany, obtaining an MSc in 1959 at Cornell University, where he also earned his PhD five years later. He married Alice Crawford in 1959, with whom he honeymooned at the Montreal Botanical Congress. They spent the next two years in Malaysia and Southeast Asia, where Nicolson carried out work on his thesis.

In 1964 Nicolson joined the herbarium of the Smithsonian Institution and made trips in the following few years to Dominica, Nepal and Bangalore. In the latter location he collaborated with Cecil J. Saldanha on the flora of the Hassan District. A keen field botanist, he spent a month collecting Araceae in Sri Lanka in 1979 and three months in Yunnan Province, China, in 1983. Among his publications are his PhD thesis, A Revision of the Genus Aglaonema (Araceae) (1969) and The Forsters and the Botany of the Second Cook Voyage (1772-1775) (2004). He has been much involved with the International Association for Plant Taxonomy, as regional treasurer, vice president and president, for example. He is also an active member of the Washington Biologists' Field Club.

Sources:
R. DeFilipps, 1999, "A Prolific Asian Plant Corrector", The Plant Press, National Museum of Natural History Smithsonian Institution, 2(1): 1
M.C. Perry, C.S. Bond and E.J.R. Lohnes, 2007, Washington Biologists' Field Club, USGS:
http://www.pwrc.usgs.gov/resshow/perry/bios/NicolsonDan.htm, accessed 15 December 2010.