German lichenologist.
Henricus (Harrie) Johannes Maria Sipman (born 1945) is a retired Dutch lichenologist who specialised in tropical and subtropical lichens and authored or co-authored over 250 scientific publications. He was the curator of the lichen herbarium at the Berlin Botanical Garden and Botanical Museum from 1983 until his retirement in 2010. Between 1990 and 1997 he edited and distributed the exsiccata Lichenotheca Latinoamericana a museo botanico Berolinensi edita.