The infill of an abandoned branch of the small river Vlootbeek, a tributary of the Meuse, revealed a record of the vegetation history from the Allerød to the Middle Ages, albeit with at least two hiatuses in its upper reach. Striking observations are the continuous presence of Pinus in a period long after this tree was absent elsewhere in the Dutch landscape, and the high percentages of Tilia pollen in the mid-Holocene. The former is explained by the sandy–gravelly subsoil in the valley of the Vlootbeek. The latter is ascribed to the short distance between the coring location and the plateau on which Tilia must have been the dominant tree. Anthropogenic influence is apparent from the Early Neolithic Linearbandkeramik farmers onwards.

Publication in 2012 of Tilia paucicostata Maxim. subsp. dictyoneura (V.Engl.) Pigott (Tiliaceae) was not valid because the publication by Engler in 1909 was not the work in which the intended basionym, T. dictyoneura, had been validly published, being predated by that of C.K. Schneider earlier in the same year. The new combination Tilia paucicostata subsp. dictyoneura (V.Engl. ex C.K.Schneid.) Pigott is validly published here, and designation of the lectotype is confirmed.

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.

Nine populations of Tilia dasystyla Steven (Tiliaceae) in the Crimean mountains (Krymskiye Gory), including the type locality at Kastel Dag, were studied in the field and sampled by collection of herbarium specimens. This material was compared with specimens referred to Tilia hegonifolia Steven collected in Crimea, the Caucasus and Iran. Measurements or scores of 21 morphological characters made on the dried material were analysed by principal components analysis and logistic regression. These analyses demonstrated that the majority of trees could be correctly allocated to either Crimea or the Caucasus and Iran on the basis of the shape of their leaves and the area of their bracts. In addition there are differences of leaf and bract texture and bract colour which can be observed in fresh material. Chromosome counts showed that Crimean trees and one Caucasian tree are tetraploid (2n = 164). It is proposed that the Crimean, Caucasian and Iranian trees be treated as a single species with at least two subspecies: Tilia dasystyla Steven subsp. dasystyla from Crimea and T. dasystyla Steven subsp. caucasica (V. Engl.) Pigott from the Caucasus and Iran.