A new species of Flacourtiaceae, Homalium palawanense, from Palawan, Philippines is described and illustrated.

The internal transcribed spacer (ITS) region of the nuclear ribosomal DNA was sequenced from 21 accessions of Viguiera from South America, including 14 from Brazil. Overall there was only a small amount of sequence variation, less than 3.4% among South American samples and less than 4.5% between the South American samples and the Mexican V. flava. Phylogenetic analysis revealed little divergence among the Brazilian samples of Viguiera. The low level of ITS sequence variation was in striking contrast to the taxonomic diversity and chemical variability that have been reported for Viguiera in Brazil. The low level of sequence variation suggests that, despite its clear morphological and phytochemical adaptations to the cerrado, Viguiera is probably a relatively recent addition (less than 3 million years) to the flora of this area.

Rhododendron loranthiflorum was previously regarded as an archipelagic endemic, with known stations in the Solomon Islands and New Britain. An exploratory survey of the Lakekamu Basin has now established the plant's presence on the southern side of the New Guinea mainland. The Lakekamu provenance represents a geographical disjunction distinguishable as a separate subspecies, and is formally described as subsp. lakekamuensis.

Salsola cyrenaica subsp. antalyensis (Chenopodiaceae) from the S Anatolian coast near Finike is illustrated and described as a new subspecies. Its anatomy, relationships, ecology and phytogeography are discussed. The new subspecies differs from subsp. cyrenaica by the reduced number of flowers per leaf axil, very dense axillary hairs, the smaller size of most floral organs, mostly 3 instead of 2 stigmas and 5 not 3 wings on the fruit. The new taxon grows in a narrow coastal strip of c.2km only, in open dwarf-shrub communities on limestone rocks from sea level to c.40m. It is the first representative of the S. longifolia group, sect. Coccosalsola, from Turkey and from the northern shores of the Mediterranean.

Pinus halepensis and P. brutia hybridize extensively. The analysis of monoterpenoid and morphological variability of 122 pine trees at five sites showed that the within-site heterogeneity is high while the entire provenance diversity is comparable with that of a circum-Mediterranean scale. Four morphotypes and four chemotypes were recognized. The congruence between morphological and monoterpenoid classification of pines was high (coefficient of contingency 89%) while thirteen family groups of genetically closely related trees were found by means of a specifically designed sampling scheme of continuous classification – identification and re-sampling. Putative hybrids contributed substantially to the observed diversity and there is considerable heterogeneity between sites. Low-altitude sites, presumably susceptible to sea-level fluctuations, alluvial deposition and human influence, are in general more diverse at both levels of genetic complexity than inland sites. The hybrid phenotypes were not merely intermediate forms of parental taxa, and in a multivariate sense they are located on a parabola in the space of morphological properties. The arrangement of hybrids in the monoterpenoid space did not reveal any clear-cut pattern except that three major composite axes can summarize 98.9% of the entire monoterpenoid variation. The observed pattern of variation was interpreted as a result of waves of introgressive influence of eastern P. brutia population on P. halepensis, which was caused by marine transgressions in Pliocene and eustatic sea-level fluctuations in Pleistocene. The human influence on this introgression accelerated the process, and amplified the resulted pattern, although it blurred in many instances the biogeographic routes of germplasm mixing. Its bearing on the evolution of pines is discussed, and it was found that the ‘Eocene refugia hypothesis’ of C.I. Millar holds by analogy also in central Aegean pines.

Internal transcribed spacer (ITS) nrDNA sequences of 42 accessions (representing 28 species) of Aframomum revealed an unusually low level of sequence variation, suggesting a recent radiation of the genus in Africa. The sample of species analysed includes all the main morphological variation and is based on wide geographical sampling. The Aframomum sequences varied from 187bp to 190bp (ITS 1) and 215bp to 216bp (ITS 2). Pair-wise sequence difference between accessions varied from 0% (e.g. A. luteoalbum and A. thonneri) to 2.74% (e.g. A. sp. nov. B to A. pseudostipulare). This contrasts with a comparable data set for the SE Asian genus Alpinia in the same tribe (Alpineae) in which maximum pair-wise difference is six times greater (range 0.5–15.6%). A parsimony analysis of the in-group and out-group taxa supports the monophyly of the genus Aframomum, but does not resolve the relationships between the in-group species. Four putative multi-species groups, however, have some jackknife support. The species sampled vary greatly in vegetative, floral and fruit characters. This morphological variation is not reflected in the ITS sequence data. This may be a result of rapid radiation under conditions of Pleistocene climatic change and effective dispersal of seeds by primates.

The following new species, subspecies and combinations are proposed for plants occurring in the Flora of Bhutan area: Anaphalis cooperi Grierson & Springate, Artemisia bhutanica Grierson & Springate, Ixeridium beauverdianum (H.Lév.) Springate, Ligularia lancifera (J.R.Drumm.) Grierson, L. latiligulata (R.D.Good) Springate, Parasenecio chenopodifolius (DC.) Grierson, Saussurea donkiah C.B.Clarke ex Springate, S. pinnatiphylla Grierson & Springate, Tanacetum tatsienense var. tanacetopsis (W.W.Sm.) Grierson and Youngia silhetensis subsp. bhutanica Grierson & Springate. A description of Ligularia latiligulata is provided. A lectotype is designated for Saussurea obscura Lipsch.

Seven new species and one new subspecies in Scrophulariaceae from the Flora of Bhutan area are described. They include two new species of Euphrasia, E. chumbica R.R. Mill sp. nov. (Chumbi, Sikkim and C Bhutan) and E. melanosticta R.R. Mill sp. nov. (Sikkim, N Bhutan); one new species of Kickxia, K. papillosa R.R. Mill sp. nov. (E Bhutan); one new species of Lagotis, L. chumbica R.R. Mill sp. nov. (Chumbi); one new species of Neopicrorhiza, N. minima R.R. Mill sp. nov. (N Bhutan); two new species of Scrophularia, S. cooperi R.R. Mill sp. nov. (C Bhutan) and S. subsessilis R.R. Mill sp. nov. (N Bhutan); and a new subspecies of Ellisiophyllum pinnatum (Wall.) Makino, subsp. bhutanense R.R. Mill subsp. nov. (Bhutan). Alectra avensis (Benth.) Merr., Bacopa monnieri (L.) Pennell, Scrophularia himalayensis Royle, Striga asiatica (L.) Kuntze and S. densiflora Benth. are all recorded from Bhutan and/or Sikkim for the first time. A brief argument is given for the continued use of hyphenated fel-terrae as the correct spelling of that epithet in Picria.

This study treats some structural aspects of a population of Callisthene fasciculata (Spr.) Mart. growing on a ridge in the Pantanal of Poconé, in Mato Grosso State, Brazil. The project was carried out in 1ha of cerradão (savanna forest) at Fazenda Retiro Campo Largo, Poconé. Callisthene fasciculata is a common species in the cerradão. Formations of C. fasciculata, regionally denominated `carvoeiro' and/or `carvoal', occur frequently. This species is of economic importance because of its use for fence posts, charcoal and firewood. Data on its population structure were analysed and are presented based on the circumference class categories at breast height (cbh) and variation in height. The 869 individual trees in the sample hectare included 17 families and 33 species, and were dominated by the 229 individuals of C. fasciculata.

The Pleistocenic Arc, which must have originated from the climatic shifts in South America during the late Pleistocene, ranges from the Caatingas of north-eastern Brazil through south-eastern Brazil to the Paraguay and Paraná rivers confluence, into south-western Bolivia and north-western Argentina, and extends sporadically into dry Andean valleys of Peru or coastal western Ecuador. It is regarded as a new phytogeographic unit for South America, here named the Tropical Seasonal Forests Region, as it is characterized by a considerable number of endemic plant taxa at both generic and species level. The paradigm of the arc is the distribution pattern of Anadenanthera colubrina (Fabaceae), which, when superimposed on those of other woody species of seasonal forests, permits a reasonably accurate mapping of the new region, which might also have biogeographic implications for endemic bird taxa. The plant communities of this newly recognized unit are unique in their nature and floristic composition, when compared with other floristic areas of the continent by means of classic phytosociological and numerical analyses (PCA). These ecosystems have remained submerged within other vegetation units in South American phytogeography (such as the Chaquenian or Amazonian regions), and have been particularly neglected in conservation policies. An urgent call is made for these areas to be preserved before they disappear, because they are located in areas with some of the best agricultural soils of tropical South America, and therefore subject to clearing for farming.