Two keys to distinguish the genera Grewia and Microcos are presented, one based on macromorphological characters and the other on micromorphological characters. Grewia is revised for Peninsular Malaysia and Borneo. Despite the 33 names published under Grewia for the region only four species are recognized here. Grewia multiflora is newly recorded from Borneo and attention is drawn to its curious distribution; G. huluperakensis is endemic to Peninsular Malaysia; G. polygama is found in limestone forest in northern Peninsular Malaysia, and G. laevigata is common in Peninsular Malaysia and Borneo. A key, descriptions and illustrations are provided for all four species. A list of excluded species names is included: all are referable to Microcos.

The evolutionary relationships of several, mainly Iberian, Jasione taxa (Campanulaceae) were investigated using molecular data. A parsimony analysis of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA was partially successful in elucidating some interspecific alliances. One of the main clades included three morphologically rather disparate species from S Spain and Morocco which might indicate that these areas were refugia during the last glaciations. The fact that most of the other taxa fell in a large polytomy suggests a recent origin of these species. Amplified fragment length polymorphisms (AFLPs) were analysed for a larger sample set of two taxa from within the ITS polytomy to assess the partition of genetic variation between and within populations. All the British accessions named J. montana var. montana were found to be close to those so-named from Spain. However, individual accessions of J. montana var. montana from Argyll (Scotland), Devon (SW England) and the Shetland Islands proved to be genetically different from each other. This might suggest a low level of genetic diversification from a common progenitor due to a rapid northward migration. It is proposed that J. montana var. bracteosa and J. maritima var. sabularia merit recognition at higher rank. The possibility that J. montana vars gracilis and latifolia are mere repetitive segregants of J. montana var. montana is considered.

Mitotic chromosome numbers and karyotypes of species in two sections of Lycium (Solanaceae) from the American continent were determined in 23 populations. Both species in the small South American section Schistocalyx were examined: Lycium ciliatum and three varieties of L. chilense had diploid (2n=24) as well as tetraploid (2n=48) populations. Lycium ameghinoi from the small American section Sclerocarpellum was diploid with 2n=24. The basic number x=12 for the genus was confirmed. The karyotypes of these taxa were highly symmetrical: the chromosomes were metacentric or submetacentric with the formula: 11 m + 1 sm. Microsatellites were present in chromosome pair no. 1 and were attached to the short arms. As in other Lycium taxa already investigated, karyotypic features suggest that morphological differentiation in the group has not been accompanied by karyotype divergence.

The purpose of the present study was to investigate the correlations between environmental variables related to the substrate (soil and topography) and the distribution of tree species in a valley forest in the Chapada dos Guimarães National Park, Mato Grosso State, Brazil. The forest lies in the Cerrado Domain of Central Brazil where the dominant vegetation cover is cerrado (woody savanna). A survey of the tree community registered all live individuals with circumference at breast height (cbh)≥15cm found in eighteen 600m2 plots (total area 1.08ha). The substrate variables used in the gradient analyses were obtained from a topographic survey and from analyses of the chemical and physical properties of soil samples. A principal components analysis of soil and topography variables and a canonical correspondence analysis of the species–environment relationships produced similar results, separating both the substrate variables and the tree species abundances, mainly according to the two types of bedrock, sandstone or slate, underlying their soils, and secondly to the three topographic sectors recognized: Streamside, Mid Slope and Upper Slope. The differences in soil fertility and texture (related to the bedrocks) and the soil water regime (related to both soil texture and topography) were probably the chief factors determining the distribution of tree species in the forest.