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The pollen morphology of 54 species and one variety of seven genera in Polygonatae including Clintonia, Disporopsis, Disporum, Maianthemum, Polygonatum, Smilacina and Streptopus was observed and studied in detail; of these, nine species were reported for the first time. Our results showed that the surface ornamentation of pollen grains of the studied materials could be divided into seven types, namely gemmate, granulate-foveolate, perforate, reticulate, rugulate, rugulate-perforate and verrucate. In line with previous studies, we believe that (i) Smilacina ginfushanicum should be classified into the genus Heteropolygonatum rather than the genus Smilacina; (ii) Polygonatum should be divided into section Polygonatum and section Verticillata; (iii) Smilacina and Maianthemum should be combined as one genus, i.e. Maianthemum sensu lato; and (iv) Clintonia, Disporum and Streptopus should be separated from the tribe Polygonatae.

We report results of karyotype analyses using nine species of Maianthemum from China. The species, except M. atropurpureum (with 2n = 72), had 2n = 36, and the results support the earlier suggestion that Maianthemum has x = 18 with 2n = 36 in most species. The species examined, however, showed marked differences in karyotype, particularly in the numbers of metacentric, submetacentric, and acrocentric chromosomes as well as in the number of satellites. In addition, we distinguished three different modes based on the number of clear gaps in chromosome length variation: unimodal, bimodal, and trimodal. The unimodal variation (with no gap) was found in M. dahuricum and M. atropurpureum, the bimodal variation (with one gap) in M. tatsienense, and the trimodal variation (with two gaps) in M. bifolium, M. forrestii, M. japonicum, M. henryi, M. purpureum, and M. lichiangense. In the trimodal variation, the positions of the two gaps may differ from species to species. In addition, the frequency of acrocentric chromosomes per complement was generally higher in the trimodal variation than in the unimodal and bimodal variations. Results of our analyses, which had not been clearly presented prior to this, may provide a better understanding of species evolution in the tribe Polygonatae.

The chloroplast gene encoding ribulose-1,5-bisphosphate-carboxylase (rbcL) was sequenced for phylogenetic analysis of 13 species (10 genera) in the tribe Polygonatae s.l. of the Liliaceae-Asparagoideae. The data were analysed using maximum parsimony and neighbour-joining methods. There were 233 phylogenetically informative sites out of 1368 base pairs compared. The results suggest that there are three monophyletic groups within Polygonatae s.l. with high bootstrap confidence values. Group A represents Polygonatae s.str., with genera Maianthemum, Smilacina, Convallaria, Disporopsis, and Polygonatum. Group B contains Uvularia and Disporum and group C includes Streptopus, Tricyrtis, Clintonia, and Prosartes. The study suggests that Polygonatae s.l. are not a monophyletic group, including at least three groups of different phylogenetic origin. Monophyly of the taxa within groups A, B, and C is supported by the high bootstrap confidence values (85— 100%) of the bootstrap replications for both parsimony and neighbour-joining methods. The differences between each group (calculated as 100x base substitutions per site) were 6.99—9.03 for group A and B, 4.92—7.35 for A and C, and 6.66—7.57 for B and C.