False cleavers (Galium spurium L.) is an aggressive weed from the Rubiaceae. Here we assemble a chromosome scale draft of its genome, laying the foundations for determining the genetic basis of auxinic herbicide resistance and for systematic research into its polyphyletic genus. We use the genome to examine the population genetics in material from the Canadian Prairies and, in concert with a common greenhouse experiment, to examine whether the phenotypic variation observed in the field results primarily from genetic or environmental factors. The genome assembly covers approximately 85% of G. spurium’s expected 360Mbp genome size with 94% of BUSCO genes complete and most single copy (89%). Approximately 37% of the genome is repetitive elements and 35,540 genes were annotated using RNA-Seq data, including 100 homologs for genes involved or, potentially involved in, herbicide resistance. The genome shows strong synteny with other members of the Rubiaceae including smooth bedstraw (Cruciata laevipes Opiz) and robusta coffee [Coffea canephora (Pierre ex Froehner]. Double digested RADseq data for the 19 populations from the Canadian Prairies indicated that G. spurium has high levels of population structure (FST = 0.54) and inbreeding (FIS =0.86) with low levels of hetrozygosity (HO = 0.02) and nucleotide diversity (π = 0.0003). Variation in flowering time and seed weight largely overlapped among populations grown in the greenhouse. A redundancy analysis investigating genotype-phenotype associations showed few associations between SNP variation and these characteristics. In contrast, the majority of SNPs under selection were associated with mericarp hook density. This suggests that for most traits, environmental variation rather than genetic variation likely underlies phenotypic differences observed in the field. Several genes of interest including several homologs involved in the assembly of the Skp1-Culliun-F-Box IR1/AFB E3 ubiquitin ligase complex (e.g. CAND1, ECR1) are located in areas of the genome with evidence of selection and are targets for further investigation.

Micromorphological features of vegetative and reproductive organs in plants are considered important because they can be used as taxonomic characters. Asperula cankiriense B. Şahin & Sağıroğlu, commonly known as “Çankırı belumu”, belongs to the family Rubiaceae and generally occurs in gypsum steppes. This research reports for the first time the micromorphological characteristics of the vegetative and reproductive organs of A. cankiriense using light and scanning electron microscopy. Taxonomically critical diagnostic features, such as raphide crystals, presence and shape of trichomes, leaf cross-section shape, flower structure, and epidermal ornamentation, were described in detail. This study provided up-to-date information on the micromorphology of this newly described species and provided additional systematic information on A. cankiriense. New data about the species are reported here and will contribute to the knowledge about the family Rubiaceae.

A new species, Hedyotis rajasekaranii Karupp. & Ravichandran (Rubiaceae), is described from the Megamalai Hills of the Western Ghats in Tamil Nadu, southern India.

Morinda reticulata Gamble and Morinda umbellata Linn. (Rubiaceae) are medicinally important climbers distributed as a mixed population in southern Western Ghats of India. A close morphological resemblance of these two species misleads the harvester in the identification of plant parts for preparation of herbal medicines. Though both species contain anthraquinone derivatives and share common medicinal properties for treating stomach disorders, each of these species has unique curative properties for treating selective diseases. Conventional methods are not reliable for identification of these species due to similarities in morphology. Thus, misidentification often leads to the deterioration of the quality of medicines. Thus, authentication utilizing conserved gene sequences in the chloroplast genome of these two Morinda spp. has been attempted for precise identification. Here we report the use of two barcoding genes (maturase kinase and ribulose 1,5-bisphosphate carboxylase large subunit) to distinguish M. reticulata and M. umbellata based on single nucleotide polymorphism. The present findings can be used for authenticating leaf samples of M. reticulata and M. umbellata.

Coexistence of closely related species is a central issue in community ecology, and those species are expected to present niche differentiation, particularly when resources become scarce (García & Arroyo 2005). Hence, resource abundance and diet differences might be playing a key role in determining species coexistence (Chapman & Rosenberg 1991, Stevenson et al. 2000). Trophic niche differentiation in frugivorous birds could be driven by fruit selection, morphology, behaviour (Moermond & Denslow 1983, 1985) and the spatiotemporal resource dynamics (Blake & Loiselle 1991, Saracco et al. 2005, Solórzano et al. 2000).

A description of the defining characteristics of Gardenia (Rubiaceae) and a revision of the Philippine species distinguished mainly by calyx morphology are presented. A key to five species of Gardenia recognised for the Philippines, full descriptions and illustrations, and a list of names which should be excluded from Gardenia are given. Relevant Philippine names for which holotypes were not indicated or have been destroyed are lectotypified. Two new endemic species, Gardenia ornata K.M.Wong and G. vulcanica K.M.Wong, are described. Gardenia elata Ridl. and G. mutabilis Reinw. ex Blume are newly applied to Philippine species previously enumerated under other names. Gardenia pseudopsidium (Blanco) Fern.-Vill. is considered a doubtful name, to which some authors have referred the endemic G. barnesii Merr.

Three new species of Rubiaceae from Central Africa are described and illustrated. Chassalia lutescens O.Lachenaud & D.J.Harris (widespread from Cameroon to Democratic Republic of Congo) is recognised inter alia by the T-shaped ventral furrow of the seeds and the orange-yellow discoloration of inflorescences in herbarium specimens. Psychotria nodiflora O.Lachenaud & D.J.Harris (Central African Republic, Congo-Brazzaville and Democratic Republic of Congo), belonging to Psychotria subgen. Psychotria sect. Involucratae, is unique among African species of the genus in having paired axillary inflorescences. Psychotria pteropus O.Lachenaud & D.J.Harris (Central African Republic and Democratic Republic of Congo) belongs to Psychotria subgen. Tetramerae; it is closely related to P. leptophylla Hiern but differs in its narrow corolla tube and globose to ellipsoid fruits.

The taxonomic history of Porterandia (Rubiaceae) is reviewed. Its plant architecture and other morphological characteristics are compared with those of the related Atractocarpus and Bungarimba. Porterandia species are typically gynodioecious (and sometimes gynomonoecious), with sexual dimorphism in inflorescence form and flowers. Secondary pollen presentation in bisexual flowers is present. In a cladistic analysis using 34 morphological characters, Porterandia, Atractocarpus heterophyllus (type species of Atractocarpus) and Bungarimba were neatly polarised from Aidia, the outgroup. The 20 species of Porterandia in the analysis formed a well-supported monophyletic group, clearly delimited by primary and lower-order branches with terminal cymes in forks, stipules fused into a tube and with hairy inner surfaces, anisophyllous leaf pairs, corollas with stiff bristle-like hairs over the tube outer surface and adaxially hairy lobes. A revision enumerated 22 species of Porterandia, including a new species, P. dinghoui Zahid & K.M.Wong. Borneo, with 19 species, is the centre of diversity; outlying taxa appear to diverge from Bornean taxa in some characters; for example, Porterandia anisophylla and P. scortechinii (Sumatra, Malaya) are the only species with downward-pointing hairs on the corolla tubes (the rest have upward-pointing hairs), and P. celebica (Sulawesi) has atypical hood-like, fused (instead of free) inflorescence bracts. The northwest Borneo region has a significant species diversity and congregation. Extinction of Porterandia populations from heavily disturbed or open sites indicates that habitat conservation and the integrity of large forest patches and tree stands are critical.

Pollen and seed characters of 12 Nepalese representatives of the Hedyotis–Oldenlandia–Kohautia complex (Spermacoceae s.l.; Rubiaceae) were investigated morphologically using scanning electron and light microscopy. The members of the complex were found to show remarkable variation in fruit, seed and pollen features. Pollen grains were all colporate with the aperture number varying from 3–4 to occasionally 5. The ectoaperture was a colpus, and the endoaperture was an endocingulum, a lalongate endocolpus or an endocolpus combined with an annulus around the mesoporus. Sexine ornamentation was variable, being perforate, reticulate or microreticulate. Three species were found to have a double reticulum. Supratectal elements were generally absent, but sometimes muri were beset with granules. Seeds were numerous per capsule, small and non-crateriform. Three types of seed were distinguished based on shape: (1) lenticular with a narrow wing-like margin, (2) trigonous, and (3) globose/subglobose. Trigonous seeds exhibited marked variation in colour, size and shape. On the basis of the pollen and seed characters, used in combination with the type of fruit dehiscence, five natural groups are identified for Nepalese taxa. The generic status of Hedyotis, Oldenlandia and Kohautia is maintained but some species are transferred from Hedyotis to Oldenlandia. Pollen and seed morphology, together with the type of fruit dehiscence, proved to be helpful in delimiting supra- and infrageneric groups within the Hedyotis–Oldenlandia–Kohautia complex.

A new species of Rubiaceae, Hedyotis kottangathattiensis M.B.Viswan. & U.Manik., is described from the Kalakkad-Mundanthurai Tiger Reserve in the Agastyamalai hills of the southwestern Ghats in South India. Hedyotis kottangathattiensis is allied to Hedyotis barberi (Gamble) Henry & Subram. but differs in its branching, leaf shape and colour, the presence of raphides, the colour and shape of the stipules, the inflorescence structure, calyx lobe shape, corolla lobe shape and colour, and capsule shape. A conservation status is proposed.

A new species of Rubiaceae, Hedyotis shenzhenensis T.Chen, from Shenzhen, South China, is described and illustrated.

Specimens of Pseudopyxis Miq. (Rubiaceae) from China and Japan were studied and compared. As the plants from China differ considerably from those from Japan a new species, Pseudopyxis monilirhizoma T.Chen, is described and a key to Pseudopyxis is presented.

Two new species of Gardenia (Rubiaceae), Gardenia beamanii Y.W.Low and Gardenia chanii Y.W.Low, endemic to Borneo, are described. These species are distinguished from Gardenia griffithii Hook.f. and Gardenia pterocalyx Valeton, respectively, to which they are superficially similar in calyx characters. Gardenia pterocalyx is lectotypified.

We evaluated the effects of topography on the distribution of understorey herbs, shrubs and small trees of the pantropical genus Psychotria (Rubiaceae) in a 10000-ha rain-forest reserve in central Amazonia. As plots were long and thin, and followed altitudinal isoclines, we were able to avoid the trade off between plot size and precision of measurement of topographical variables. The minimum distance between plots (1 km) was sufficient to avoid spatial autocorrelation in topographical variables. However, indices of plot similarity based on species composition were spatially autocorrelated to distances of at least 4 km. Although Multivariate Analysis of Covariance (MANCOVA) indicated significant effects of altitude, slope, and watershed on species composition within plots, topographical variables were generally poor surrogates for species distributions. Differences between eastern and western watersheds within the reserve were not due to distance effects, and most species occurred in both watersheds, indicating that differences in species assemblages between watersheds are determined by ecological factors. Habitat specialization and local density were not clearly associated with rarity. At scales of 1–10 km, both distance and habitat affect the distribution of understorey shrubs of the genus Psychotria, but much of the variation in species abundances remains unexplained.

Interest in the colour of fruits eaten by vertebrates has a long history (Ridley 1930, Turcek 1963, van der Pijl 1972). Within a given geographical area, colours of bird-consumed fruits compared with mammal-consumed fruits are fairly consistent (Janson 1983, Wheelwright & Janson 1985, Willson & Whelan 1990), but comparisons among different regions reveal selective pressures of different animal groups (Lord 2002, Willson et al. 1989). One consistent pattern among regions is that fruits with a two-colour display typically are eaten by birds (Wheelwright & Janson 1985, Willson & Thompson 1982, Willson & Whelan 1990). Thus, it is thought that such bicoloured displays are specifically adapted to attract birds and plants with these displays presumably benefit from seed dispersal by birds (Janson 1983, Willson & Whelan 1990).

This study addresses the pollination ecology of shrub species in an upper montane forest in Costa Rica, where the diversity of insect visitors is much below that of the well-studied tropical forests of lower elevations. Data are presented on visitation rates by the tropical bumblebee Bombus ephippiatus to flowers of three species, pollen loads on bumblebee bodies, and pollen loads on stigmas of two of the species. High visitation rates to flowers of Palicourea brenesii were found, a species which produces copious amounts of nectar. Visitation rates to nectarless Leandra subseriata and Deppea grandiflora were much lower. Conspecific pollen comprised on average 90% of the pollen load on stigmas of Leandra, while Palicourea stigmas carried only 26 to 55% conspecific pollen. With only two ovules per flower, fruit and seed set in Palicourea were not limited by a shortage of conspecific pollen. In Leandra, 20–25% of the flowers received too few conspecific pollen grains for maximum seed set among 440 ovules per flower. Individual bumblebees showed no constancy in plant choice, judging from the high number of different pollen types (6–12) on their bodies. Workers returned frequently to the same Palicourea patch without visiting nearby Palicourea plants, which suggests the use of foraging paths.

Critical discussions are presented concerning two species complexes within Galium L. (Rubiaceae). the G. acutum Edgew. and G. asperifolium Wall, groups, with special reference to the E Himalayas. In the G. acutum group, two new species, G. megacyttarion R.R. Mill sp. nov. and G. rebae R.R. Mill sp. nov., are described and G. himalavense Klotzsch & Garcke is reduced to a variety of G. acutum, necessitating a new combination. Within the G. asperifolium group, G. craticulatum R.R. Mill sp. nov. is described, and G. asperifolium and G. sikkimense Gand. regarded as distinct species. The typification of several epithets (G. blinii Lev., G. bodinieri Lév., G. cavaleriei Lév., G. comari Lév. & Vaniot, and G. esquirolii Lév.), which all antedate G. sikkimense, is discussed. Only G. cavaleriei poses a potential threat but it is here maintained separate from G. sikkimense. Brief notes on G. asperifolium sensu stricto and supposedly allied plants of south India (G. asperifolium var. pilosissimum Cufod.) are given.