Chromosomal evolution in Veronica L. and related genera (Wulfenia Jacq., Wulfeniopsis D. Y. Hong, Paederota L., Lagotis Gaertn., Picrorhiza Royle ex Benth., and Veronicastrum Heist. ex Fabr.; Veroniceae, Plantaginaceae; formerly Scrophulariaceae) is presented. To this end, we conducted an extensive literature survey of more than 400 publications covering ca. 300 out of 500 species in the tribe. We also report 44 new chromosome counts. Chromosome numbers of Veronica hispidula Boiss. & Huet. (2n  =  18, 36) and V. reuteriana Boiss. (2n  =  28, 42) are reported for the first time, and both species exhibit intraspecific ploidy level variation. Other new counts confirm chromosome numbers reported previously. The evolution of chromosome numbers in Veroniceae is discussed in light of recent results from DNA-based phylogenetic analyses. Most of the subgenera of Veronica exhibit only one single basic number, i.e., x  =  6, 7, 8, 9, 12, 17, or 20/21. In this genus, the putative ancestral base number of 9 has been reduced several times to 8 and 7, respectively (aneuploidy/dysploidy), often associated with transition to annual life history. In contrast, no unambiguous increase of chromosome base number has been inferred. A table that includes all species of Veroniceae and, if known, their chromosome number and full sectional and subsectional classification in Veronica is provided. For this purpose, three new combinations have been introduced (Veronica sect. Acinifolia (Römpp) Albach, Veronica sect. Glandulosae (Römpp) Albach, and Veronica subsect. Cochlidiosperma (Rchb.) Albach).

The pantropical and subpantropical genus Mimosa L. comprises more than 500 species, of which nearly 480 are reported for the American Continent. Mimosa is subdivided into five sections, four of which are represented in southern South America: Batocaulon DC., Habbasia DC., Calothamnos Barneby, and Mimosa. Previous taxonomic studies of the species from the austral region have found classification conflicts among (a) sections Batocaulon and Habbasia, (b) sections Calothamnos and Mimosa, and (c) series and subseries within section Mimosa. This paper reports a preliminary phylogenetic analysis of chloroplast nucleotide sequences of the trnL intron and the trnL-trnF intergenic spacer from 34 species of Mimosa and related genera. Key morphological characters were mapped onto the phylogenetic hypothesis and discussed. Sequence analysis indicates that the genus Mimosa is monophyletic; it is derived from Piptadenia viridiflora (Kunth) Benth. The four sections proposed by Barneby are not natural groups. The cladogram retrieved indicates that the representatives of Mimosa sect. Batocaulon are not clustered, the xerophylous representatives of this section are basal, and the remaining species are related to those species of section Habbasia, suggesting that section Batocaulon ser. Stipellares is more recently derived. The species of Mimosa sect. Calothamnos that were analyzed are nested in section Mimosa. The results seem to support retention of this section within section Mimosa as was noted previously by Bentham. The chloroplast sequence data suggest that the representatives from sections Calothamnos and Mimosa share a common ancestor with those from section Habbasia and section Batocaulon ser. Stipellares.

Nuclear DNA ITS and ETS sequences of 71 representatives from nine genera and 11 sections of the core Laureae were combined with a matrix of morphological characters, analyzed using maximum parsimony with both equally and successively weighted characters, and analyzed for Bayesian inference, minimum evolution by neighbor joining, and maximum likelihood inference for molecular data alone. The large genera Actinodaphne Nees, Lindera Thunb., and Litsea Lam. were polyphyletic, as were Lindera sect. Aperula (Blume) Benth. and Litsea sections Conodaphne (Blume) Benth. & Hook. f., Cylicodaphne (Nees) Hook. f., and Tomingodaphne (Blume) Hook. f. In contrast, Neolitsea (Benth.) Merr. was monophyletic and terminal in a larger monophyletic lineage above an Actinodaphne grade. A major disparity exists between these molecular results and traditional morphology-based classifications within Lauraceae. These results suggest that the use of two- versus four-celled anthers for Laureae generic delimitation has resulted in polyphyletic or paraphyletic genera, and the character of dimerous versus trimerous flowers is of only limited phylogenetic value. Several of the major lineages in Laureae are supported by inflorescence morphology and ontogeny, with Laureae defined by short shoots with a vegetative terminal bud, splitting into thyrsoid (Actinodaphne and Neolitsea) versus racemose (Laurus, Litsea s. str., and Lindera s. str. and Lindera sect. Aperula), although there appear to be at least two different pathways to form the Laureae pseudo-umbel. Similarly, imbricate, early deciduous inflorescence basal involucral bracts defined an Actinodaphne–Neolitsea–Parasassafras–Sinosassafras clade, although within it, Neolitsea was defined in part by decussate, persistent bracts. Accordingly, our study indicates the need for caution in the use of morphology for assessing affinity in Laureae, as virtually all traditional morphological characteristics show high levels of homoplasy and/or reversal, but future research may help to resolve whether this indicates problems of homology or ontogenetic convergence.

Field studies were conducted for 15 species of Iochroma Benth. and the nested genus Acnistus Schott to quantify the diversity of pollination systems and to assess the potential contribution of pollinator behavior to the persistence of closely related species in sympatry. We combined measures of pollinator visitation and pollen deposition to estimate the importance of major groups of pollinators for each species, and we calculated proportional similarity in the pollinator assemblage among species. We found that 12 species of Iochroma, encompassing a range of flower colors and sizes, were principally pollinated by hummingbirds and, in many cases, by the same hummingbird species. The remaining species were either pollinated by a mix of hummingbirds and insects (two species) or exclusively by insects (two species). Based on proportional similarity values, the overlap in pollinator assemblages was found to be higher for sympatric species than for allopatric ones, reflecting sharing of local pollinator fauna. However, observations of individual pollinator fidelity, perhaps related to territorial interactions among hummingbirds, suggested that pollinators may still contribute to the reproductive isolation of sympatric congeners. Nonetheless, because interspecific pollen flow does occur, the maintenance of species boundaries in sympatry probably requires postmating reproductive isolating mechanisms.

A synoptic treatment of the Tachigali Aubl., including Sclerolobium Vogel, in northern South America (Colombia, Venezuela, Guyana, French Guiana, Suriname, Amazonian Brazil, Ecuador, and Peru) is presented and contains brief descriptions of, and a key to, the 54 species recognized in northern South America. Ten species, T. barnebyi van der Werff, T. bicornuta van der Werff, T. candelabrum van der Werff, T. cenepensis van der Werff, T. chrysaloides van der Werff, T. ferruginea van der Werff, T. fusca van der Werff, T. inconspicua van der Werff, T. loretensis van der Werff, and T. vaupesiana van der Werff, are newly described. Three overlooked names published by Tulasne (T. glauca, T. poeppigiana, and T. richardiana) have been taken up again. One new combination, T. melanocarpa (Ducke) van der Werff, is proposed. Lectotypes are designated for three species, T. alba Ducke, T. melanocarpa, and T. plumbea Ducke. The following species are placed in synonymy: Sclerolobium froesii Pires in T. bracteosa (Harms) Zarucchi & Pipoly; T. tessmannii Harms in T. formicarum Harms; T. myrmecophila (Ducke) Ducke in T. glauca; S. radlkoferi Rusby, S. uleanum Harms, and S. subbullatum Ducke in T. guianensis (Benth.) Zarucchi & Herend.; T. grandiflora Huber, T. ulei Harms, T. rusbyi Harms, and T. pulchra Dwyer in T. paniculata Aubl.; T. sulcata Benoist and T. bracteolata Dwyer in T. richardiana; and T. reticulosa (Dwyer) Zarucchi & Herend. in T. tinctoria (Benth.) Zarucchi & Herend.

The flora of Xishuangbanna in southern Yunnan, southwestern China, consists of 3340 native seed plant species belonging to 1176 genera and 182 families. Tropical floristic elements at the generic level form a major contribution (78.3%) to the total flora of southern Yunnan, of which the dominant geographic elements are those of tropical Asian distribution. The tropical Asian flora of Xishuangbanna is similar in composition to other tropical floras from Yunnan, especially in the families with the most species richness. These regional floras have similarities of more than 89% at the family level and more than 76% at the generic level, but share only 43%–50% similarity at the specific level. Comparison with mainland Southeast Asia (Thailand) and Malesia (Malay Peninsula) floras reveals that most of the dominant families from southern Yunnan are also dominant in mainland Southeast Asian and Malesian floras. The floristic similarities between the flora of southern Yunnan and those of tropical Asia are more than 80% at the family level and more than 64% at the generic level. This suggests that the tropical flora of southern Yunnan has a close affinity with tropical Asian flora and supports the idea that the flora of southern Yunnan, together with mainland Southeast Asian flora, belongs to the Indo-Malaysian floristic subkingdom of the Paleotropical kingdom as suggested by Takhtajan, or the Malaysian subkingdom of the Paleotropical kingdom as suggested by Wu and Wu. However, situated at the northern margin of tropical Asia, the flora of southern Yunnan comprises less strictly tropical elements compared to Malaysian flora and, consequently, represents only a marginal type of Indo-Malaysian flora. The tropical flora of southern Yunnan is supposed to be derived from tropical Asian flora with the formation of the eastern monsoon climate after the Tertiary.