Chromosome numbers for all 23 species of Tilia recognized by the author, and for several subspecies and hybrids, are reviewed. Counts or cytometric analyses for 14 species are reported for the first time; of these, eight species are diploid (2n=82): T. amurensis subsp. taquetii, T. chingiana, T. endochrysea, T. kiusiana, T. mandshurica, T. caroliniana, T. heterophylla and T. mexicana, five are tetraploid (2n=164): T. chinensis, T. henryana, T. miqueliana, T. mongolica and T. paucicostata, and one is octoploid (2n=328): T. nobilis. T. japonica, previously reported as diploid, is tetraploid in Japan (Hokkaidō) and in China. Three new combinations are created: T. amurensis Rupr. subsp. taquetii (C.K. Schneid.) Pigott, T. cordata Mill. subsp. sibirica (Bayer) Pigott and T. platyphyllos Scop. subsp. corinthiaca (Bosc ex K. Koch) Pigott.
