The chemistry and geographical distribution of the non-saxicolous species of Lecidella are reviewed. The genus is characterised chemically by the abundant occurrence of chlorinated xanthones. The chemotypes of the taxa are listed. Although most species occur in both hemispheres, several species are restricted to either the Northern or Southern Hemisphere. The centre of diversity of non-saxicolous species of Lecidella is in the Northern Hemisphere. Five new combinations are proposed: Lecidella aeruginea (H. G. FALK) KNOPH & LEUCKERT comb. nova, Lecidella leprothalla (ZAHLBR.) KNOPH & LEUCKERT comb. nova, Lecidella sendaiensis (ZAHLBR.) KNOPH & LEUCKERT comb. nova, Lecidella tumidula (A. MASSAL.) KNOPH & LEUCKERT comb. nova, Lecidella xylophila (TH. FR.) KNOPH & LEUCKERT comb. nova. Key words: Chemotypes, distribution, xanthones, Lecidella, lichens.