Three new species of Aeschynanthus (Gesneriaceae) from Sulawesi (Celebes), A. batesii, A. burttii and A. lobaticalyx, are described and illustrated. The phylogenetic position of A. batesii and A. lobaticalyx is briefly discussed; A. burttii has not yet been sequenced.

Nine species of Cyrtandra (Gesneriaceae) are recognized in Peninsular Malaysia. Three (C. cupulata, C. pendula and C. wallichii) are common and occur more or less throughout the area; C. pendula is also recorded from Singapore. Four (C. dispar, C. gimlettei, C. patula and C. suffruticosa) have more restricted distributions, and two (C. lanceolata and C. stonei) are local endemics. Three species and one variety originally described by Ridley are here reduced to synonymy: C. barbata (=C. cupulata), C. falcata (=C. suffruticosa) and C. rotundifolia (=C. pendula), and C. cupulata var. minor (=C. cupulata). Keys for fieldwork and herbarium use are presented and general information is provided. The appendix by M.H. Bokhari contains descriptions of leaf anatomy for eight of the nine species recognized and a key based on anatomical characters.

Chirita sect. Liebigia (Gesneriaceae), endemic to Sumatra, Java and Bali, is revised, paying particular attention to inflorescence and anther characters, the latter being illustrated. Whereas a previous worker considered the section to consist of the single species C. asperifolia, the present revision recognizes 12 species. Six are newly described (C. adenonema, C. dissimilis, C. leuserensis, C. praeterita, C. tenuipes and C. tobaënsis), and C. blumei var. cordifolia is given specific rank as C. neoforbesii. Notes on the history and nomenclature of sect. Liebigia are given in an appendix by B.L. Burtt.

A length polymorphism in the trnL/trnF intergenic spacer was used as a marker to determine the mode of chloroplast inheritance in Streptocarpus (Gesneriaceae). Exclusively maternal inheritance was recorded for all the F1 progeny of reciprocal intraspecific crosses between S. primulifolius and a population referred to as S. aff. primulifolius from the Igoda River mouth, Eastern Cape, South Africa, and for interspecific crosses between S. rexii and S. dunnii. A combination of molecular and morphological data was used to clarify the origin of S. aff. primulifolius, which possesses S. rexii-type cpDNA and rDNA, while the morphological data suggest an intermediate position between S. rexii and S. primulifolius. The distribution of S. rexii and S. primulifolius, combined with molecular and morphological data, supports the hypothesis that the S. aff. primulifolius population is a hybrid between S. rexii and S. primulifolius, with S. rexii as the maternal parent, and that substantial molecular but limited morphological introgression into S. primulifolius has taken place.

The new species Streptocarpus lilliputana (Gesneriaceae), collected on the Pondoland coast, South Africa, is described. Although its alliances are not obvious in terms of corolla morphology and rosulate habit, it approaches S. gardenii and its allies. The pollen and stigma of S. lilliputana differ markedly from the stenopalynous grains and bilobed stigmas of the other South African rosulate species. Streptocarpus lilliputana is exceedingly rare and is a further endemic from the Pondoland centre.

Four new species of Columnea (Gesneriaceae) section Collandra (syn. Dalbergaria Tussac) are described from the remnant forests of the western and central cordilleras of Colombia: C. coronocrypta, C. coronata, C. pedunculata, and C. queremalensis. The flowers of C. coronata are unusual in the genus in having a corona, as in genera of Gesneriaceae pollinated by euglossine bees. Columnea pedunculata is distinct in having pedunculate inflorescences.

Our knowledge of cytological data published on members of the family Gesneriaceae is summarized and critically evaluated in the light of current taxonomic treatments and phylogenetic hypotheses. There are about 1000 published chromosome counts, covering 56% of the genera but only 18% of the species. In particular the New World tribes Beslerieae and Napeantheae and the Old World tribe Didymocarpeae are underexplored at generic level. In Gesneriaceae chromosome data are a valuable source of taxonomic characters. From our current knowledge of the phylogenetic relationships in the family we know that basic chromosome numbers in the New World subfamily Gesnerioideae appear to be rather conserved, but that a more complex pattern of genome evolution seems to be present among the Old World tribes. Both polyploidy and dysploid changes have played a significant role in the evolution of the family. However, the number of species for which both cytological and molecular data are available is at present too low to reach firm conclusions on ancestral basic chromosome numbers, particularly for the Old World group. To facilitate wider access to cytological data on the Gesneriaceae, a website has been developed (http://www.rbge.org.uk/rbge/web/search/index.jsp), which is introduced in this paper.

The morphological characteristics of mitotic interphase, prophase and metaphase nuclei were analysed for 21 taxa in 14 genera from three different tribes of subfamily Cyrtandroideae (Gesneriaceae) from Asia. Interphase nuclei were classified into three categories: (1) complex chromocentres, as in Ancylostemon, Briggsia, Briggsiopsis, Chirita, Loxostigma, Lysionotus, Oreocharis, Petrocosmea, Raphiocarpus and Whytockia, (2) simple chromocentres, as in Paraboea and Rhabdothamnopsis, and (3) round prochromosomes, as in Anna and Didymocarpus. Species with complex chromocentres seem to be most common among all three tribes. The data further indicate that tribe Didymocarpeae is cytologically much more heterogeneous than other tribes, which accords with the diversity in morphological characters. Three types of chromosome condensation pattern during mitotic prophase were observed, here described as interstitial, gradient and proximal. Except for Ancylostemon, exhibiting a proximal type, and Lysionotus and Whytockia possessing a gradient type, all other species analysed to date exhibit the interstitial type. Our study also reports the chromosome numbers of 12 species in 10 genera of subfamily Cyrtandroideae from China and Vietnam; 11 of these counts are new.

Anisocotyly, the prolonged meristematic growth of one of the two cotyledons, is a distinctive feature of Gesneriaceae subfam. Cyrtandroideae. The larger cotyledon, the macrocotyledon, often grows to resemble a normal foliage leaf, and in some taxa may be the only foliar organ of the plant. This raises a number of questions. Which cotyledon becomes the macrocotyledon? Is this pre-determined in the embryo or differentiated after germination? Which external factors such as gravity and light are involved? The observation that the macrocotyledons of unifoliate Gesneriaceae growing on steep rocks mostly point downwards suggests that gravity is involved, but it is not clear whether it plays an initial determinant role or merely later influences orientation. In order to identify possible controlling factors, several experiments were performed, mostly on material of Chirita lavandulacea and Streptocarpus rexii. All seedlings responded significantly to light, the cotyledon further from the light source becoming the macrocotyledon. Seedlings growing in inclined pots with the light source below the pots mostly developed an upper macrocotyledon. The explanation proposed is that this cotyledon receives more light when the two cotyledons unfold after germination. Later on, apparently due to gravity, Chirita seedlings showed re-orientation with the macrocotyledons ultimately pointing downwards, though in Streptocarpus no such downwards re-orientation was observed. This difference is probably correlated to a difference in hypocotyl structure. Our conclusion is that while light is the initial factor controlling macrocotyledon development, gravity may cause re-orientation in some species.

A phylogenetic analysis of the tribe Zingibereae (Zingiberaceae) was performed using nuclear ribosomal DNA (ITS1, 5.8S and ITS2) and chloroplast DNA (trnL (UAA) 5′ exon to trnF (GAA)). The tribe is monophyletic with two major clades, the Curcuma clade and the Hedychium clade. Paracautleya, sampled for the first time, comes out as predicted while Caulokaempferia comes out in a different position from that found in another recent study. The genera Boesenbergia and Curcuma are apparently not monophyletic.

The genus Caulokaempferia (Zingiberaceae) is recorded for the first time from Laos with the description and illustration of the new species C. burttii.

The new species Caulokaempferia larsenii (Zingiberaceae) from northern Thailand is described and illustrated.

The sub-Saharan and mainly western southern African genus Babiana (Iridaceae–Crocoideae) is morphologically diverse, containing some 80 species. The Socotran B. socotrana, which differs from all other members of the genus inter alia in its trisulcate pollen grains, basic chromosome number, x=10, corms of axillary origin, and globose, colliculate–tuberculate seeds, is here excluded from Babiana and referred to the new genus Cyanixia. Other Babiana species have monosulcate pollen grains with a two-banded operculum, a basic chromosome number of x=7, terminal corm ontogeny, and derived pear-shaped seeds with a smooth glossy surface. Cyanixia socotrana was previously assigned to Babiana because of superficial similarities in morphology, including plicate leaves and blue flowers, thought at the time to be bilabiate, although now known to be actinomorphic and rotate. DNA sequence analysis using the chloroplast gene matK confirms that Babiana is a monophyletic assemblage, whereas B. socotrana is sister to the Lapeirousia/Savannosiphon clade of sub-Saharan Africa. The latter shares axillary corm ontogeny with the southern African Micranthus, Thereianthus, and Watsonia, in contrast to the more common situation in Crocoideae (including Babiana) in which the corm develops from the base of the flowering stem. The tropical African Zygotritonia, which also has axillary corm development, shares with Cyanixia a trisulcate pollen grain, but it differs markedly from that genus in its small, zygomorphic flower, undivided style, and basic chromosome number x=8. Cyanixia is here described as a new monotypic genus of Crocoideae, probably most closely allied to Savannosiphon, also a monospecific genus.

A revised generic synopsis of sub-Saharan Hyacinthaceae is presented, based on a molecular phylogenetic analysis of the family. Generic rank is accorded only to reciprocally monophyletic clades that can be distinguished by recognizable morphological discontinuities, thereby permitting an appropriate generic assignment of species not included in the analysis. Three subfamilies are recognized within the region. Subfamily Ornithogaloideae, characterized by flattened or angular seeds with tightly adhering testa, is considered to include the single genus Ornithogalum, which is expanded to include the genera Albuca, Dipcadi, Galtonia, Neopatersonia and Pseudogaltonia. Recognizing any of these segregates at generic level renders the genus Ornithogalum polyphyletic, while subdivision of Ornithogalum into smaller, morphologically distinguishable segregates in order to preserve the monophyly of each is not possible. Subfamily Urgineoideae, characterized by flattened or winged seeds with brittle, loosely adhering testa, comprises the two mainland African genera Bowiea and Drimia. The latter is well circumscribed by its deciduous, short-lived perianth and includes the previously recognized genera Litanthus, Rhadamanthus, Schizobasis and Tenicroa. The monotypic Madagascan Igidia is provisionally included in the subfamily as a third genus on the basis of its seeds, pending molecular confirmation of its relationships. Subfamily Hyacinthoideae resolves into three clades, distinguished as tribes Hyacintheae (strictly northern hemisphere and not treated further), Massonieae and Pseudoprospereae tribus nov. Full descriptions and a key to their identification are provided for all genera. New combinations reflecting the generic circumscriptions adopted here are made for most African and all Indian and Madagascan species.

The karyotype of a recently described species of Galtonia (Hyacinthaceae), G. regalis, is described and its cytotaxonomic relationship to other members of the genus examined. Since conflicting cytological patterns for the genus exist in the literature, the chromosome compositions of the three other species, G. candicans, G. princeps and G. viridiflora, are re-investigated. This study demonstrates that the karyotype of Galtonia is uniformly asymmetrical and distinctively trimodal, with 2n=16. Also included in this investigation is the allied monotypic genus Pseudogaltonia. Its karyotype is also asymmetrical, but differs from Galtonia in its chromosome number of 2n=18, and in certain other features.

The Drakensberg Alpine Centre (DAC) comprises the 40,000km2 high-altitude range of hills, mountain peaks and escarpment plateau bordering the eastern interior of southern Africa. Renowned for its species-rich flora and high levels of endemism, the DAC is here shown to support over 2800 specific and infraspecific native taxa, with c.16% of the angiosperm taxa being endemic, the latter equalling the flora of KwaZulu-Natal. Comparisons of the DAC's largest families and genera are made with those of the Cape Floral Region and KwaZulu-Natal, and the largest families are also compared with those of the Afromontane and Pondoland regions. In addition, comparisons are made between the high-altitude floras of southern and south-central Africa on the basis of their Cape element.