Colleters are multicellular secretory structures found on various organs in flowering plants. Colleters on the adaxial sides of stipules have been hypothesized to play a role in protecting the developing shoot. Rhizophoraceae is a stipulate family with a broad distribution from mangrove to montane environments, which makes the family well suited for the examination of this hypothesis, but the colleters of Rhizophoraceae are not well known. We compared species from all three tribes of Rhizophoraceae, including five inland genera and all four mangrove genera. In all species, several to hundreds of colleters, sessile or stalked, arranged in rows aggregated in genus-specific shapes, are found at the adaxial bases of open and closed stipules. Pellacalyx uniquely has additional colleters at the stipule margins. Colleters are all of the standard type, comprising a central axis of core parenchyma with large vacuoles and tannins, and an outer palisade-like epidermis with organelles involved in secretory activity. An exception is Pellacalyx axillaris, in which colleters appear as extremely small epidermal protrusions. Kandelia obovata has a tracheary element in some colleters. Pellacalyx uniquely has an unusual fleshy outgrowth on the adaxial stipule base. We propose an evolutionary sequence in which Macarisia has plesiomorphic stipule and colleter traits and the mangrove Kandelia obovata with colleter vascular traces is most derived. Colleter and stipule structures are largely concordant with habitat and phylogeny, and show taxonomic value. The strong alignment of colleter and stipule patterns with habitat is suggestive that colleters have a protective function, although some components of these patterns may be phylogenetically determined. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, ●●, ●●–●●.

Outbreeding confers an evolutionary advantage, and flowering plants have evolved a variety of contrivances for its maximization. However, neither fruit set nor seed set is realized to its fullest potential for a variety of reasons. The causes of low flower to fruit and seed to ovule ratios were investigated in naturally occurring bael trees (Aegle marmelos) at two sites for three seasons. The study established that the mass effect of synchronized flowering attracted a variety of insect pollinators to the generalist flowers; Apis dorsata was the most efficient pollinator. The seed to ovule ratio was low despite high natural pollination efficiency (c. 2400 pollen per stigma). Although pollination-induced structural and histochemical changes in the style allowed many (9.5 ± 2.1) pollen tubes to grow, only cross-pollen tubes could grow through the style. Gametophytic self-incompatibility, manifested in the stylar zone, resulted in a significantly slower growth rate of self-pollen tubes. The occurrence of obligate self-incompatibility, coupled with increased self-pollen deposition (geitonogamy), caused a significant number of flowers to abort. Fruit retention in the trees declined from 40% to 12% as a result of abortion of fruits at different stages of development. The number of mature fruits on a tree was negatively correlated (r = −0.82) with their size. It is inferred that low natural fecundity in A. marmelos is primarily a result of obligate self-incompatibility and strong post-fertilization maternal regulation of allocation of resources to the developing fruits. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 00, 000–000.

There is a long-standing debate on whether the occurrence of the iconic high-Andes Polylepis woodlands as small and isolated fragments is of natural or anthropogenic origin. We make inferences regarding the fragmentation history based on both a new population genetic study on P. besseri and a synthesis of available studies on the population genetics of Polylepis woodlands. We infer the timing of the main woodland fragmentation event by analysing: (1) the remaining levels of population genetic diversity and the relation to population size; (2) among-population genetic differentiation; and (3) the difference in genetic diversity between the offspring and adult generation. We retrieved seven publications on the population genetics of five Polylepis spp. We did not find a relationship between population size and genetic diversity, and genetic differentiation was low compared with that reported for similar plant species. These findings do not support a history of long-term fragmentation. The offspring showed a loss of genetic diversity and increasing differentiation compared with adults, suggesting that the main habitat fragmentation event is of relatively recent origin. For P. besseri, no significant differences were found between the adult and offspring genetic variation. We discuss the conservation and restoration consequences for this important high-Andean genus. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 00, 000–000.

Although most diverse in the New World tropics, approximately 100 species of Solanum (Solanaceae) are native to continental Africa and Madagascar. The majority of these are ‘spiny solanums’ (subgenus Leptostemonum). We present here the first phylogenetic reconstruction of African and Madagascan species of Solanum subgenus Leptostemonum, with 62 of 76 species native to these areas, plus an additional seven species of largely Asian distribution, using internal transcribed spacer (ITS), waxy and trnT-F regions. We identify monophyletic groups, many of which correspond to previously recognized units, although the large, traditionally recognized sections of Oliganthes and Melongena are polyphyletic. These groups are distinguished from each other by their breeding systems, with members of Oliganthes being hermaphroditic and Melongena andromonoecious. The phylogenetic relationships suggest multiple changes of breeding system between these two states, and observations of plants across their range indicate that there is considerable lability in this character. The African and Malagasy clades are largely geographically coherent, although there is evolutionary interchange between African vegetation types. All of the Madagascan endemics included in the analysis form a coherent group and probably represent an in situ radiation. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 00, 000–000.

In molecular phylogenetic studies, Lophopyxidaceae and Putranjivaceae are well supported as sisters in the large rosid order Malpighiales. As the floral structure of both families is poorly known and the two families have never been compared, the present comparative study was carried out, as part of a larger project on the comparative floral structure of Malpighiales, using microtome section series and scanning electron microscopy (SEM) studies. Similar to other angiosperm clades, it appears that the structure of the ovules is a strong marker for suprafamilial relationships in Malpighiales. Both families have two collateral pendant antitropous ovules per carpel associated with obturators (as in some Euphorbiaceae s.l., to which Putranjivaceae belonged in earlier classifications). However, in contrast with Euphorbiaceae s.l., the ovules are not crassinucellar, but either incompletely tenuinucellar or only weakly crassinucellar with a long and conspicuously slender nucellus and an endothelium, and do not have a nucellar beak, but a normal micropyle, features they share with families other than Euphorbiaceae s.l. among Malpighiales. Other shared features of the two families include the following. The outer sepals tend to be smaller than the inner ones and the sepals do not protect the gynoecium in older buds. Sepals of some taxa have a single vascular trace. A short zone of synsepaly tends to be present. Stamens tend to be antesepalous in haplostemonous flowers. A short gynophore is present. The synascidiate zone extends up to above the placenta, but is restricted to the ovary in taxa with more than one carpel. The micropyle is formed by the inner integument. The ventral carpel slits extend down into the synascidiate zone as postgenitally fused furrows. The carpels have a broad dorsal band of vascular bundles in the style. The overall floral structure of the two families corroborates their sister position well and does not support the earlier association of Putranjivaceae with Euphorbiaceae s.l. or of Lophopyxidaceae with Geraniales–Sapindales–Celastrales, which rely on shared superficial floral similarities. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 00, 000–000.

Previous phylogenetic studies have indicated that Acacia Miller s.l. is polyphyletic and in need of reclassification. A proposal to conserve the name Acacia for the larger Australian contingent of the genus (formerly subgenus Phyllodineae) resulted in the retypification of the genus with the Australian A. penninervis. However, Acacia s.l. comprises at least four additional distinct clades or genera, some still requiring formal taxonomic transfer of species. These include Vachellia (formerly subgenus Acacia), Senegalia (formerly subgenus Aculeiferum), Acaciella (formerly subgenus Aculeiferum section Filicinae) and Mariosousa (formerly the A. coulteri group). In light of this fragmentation of Acacia s.l., there is a need to assess relationships of the non-Australian taxa. A molecular phylogenetic study of Acacia s.l and close relatives occurring in Africa was conducted using sequence data from matK/trnK, trnL-trnF and psbA-trnH with the aim of determining the placement of the African species in the new generic system. The results reinforce the inevitability of recognizing segregate genera for Acacia s.l. and new combinations for the African species in Senegalia and Vachellia are formalized. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, ●●, ●●–●●.

The systematic significance of the morphological structure of achenes in the Himalayan–Tibetan Plateau endemic genera Soroseris, Syncalathium and Parasyncalathium is described and discussed. The achene surface sculpturing of 15 samples representing 13 species of the three genera was investigated using scanning electronic microscopy (SEM) to evaluate inter- and intrageneric relationships of the three genera. Characters such as cell arrangement, shape of the epidermis, type of ornamentation of the outer cell wall and degree of wax development are described. The results show that characters such as the shape of the epidermis and the type of ornamentation of the outer cell wall are distinct between the three genera and useful for species-level classification. Parasyncalathium souliei differs from Syncalathium, in which it has traditionally been placed, in the short, stout beak of the achene and especially in the obscure outline of the epidermal cells and their long acuminate, steeple-like, end walls. Combined with karyological and molecular data, the differences in achene morphology and sculpturing further support our recognition of Parasyncalathium as distinct from Syncalathium. The achene characters are not only useful for assessing relationships, but are also useful for delimiting species. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 00, 000–000.

Myrtaceae are one of the most species-rich families of flowering plants in the Neotropics. They include several complex genera and species; Hexachlamys is one of the complex genera. It has not been recognized as a distinct genus and has been included in Eugenia, based on morphological grounds. Therefore, molecular systematic studies may be useful to understand and to help to solve these relationships. Here, we performed a molecular phylogenetic analysis using plastid and nuclear data in order to check the inclusion of Hexachlamys in Eugenia. Plastid (accD, rpoB, rpoC1, trnH-psbA) and nuclear (ITS2) sequence data were analysed using Bayesian and maximum parsimony methods. The trees constructed using ITS2 and trnH-psbA were the best able to resolve the relationships between species and genera, revealing the non-monophyly of Hexachlamys. The molecular phylogenetic analyses were in agreement with previous morphological revisions that have included Hexachlamys in Eugenia. These results reinforce the importance of uniting knowledge and strategies to understand better issues of delimitation of genera and species in groups of plants with taxonomic problems. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, ●●, ●●–●●.

The aim of our study was to verify, on the basis of statistical analyses of nine quantitative morphological features of pollen grains, the hypothesis that pollen grains of three parental species of Crataegus (C. laevigata, C. monogyna, C. rhipidophylla) differed from the pollen of three spontaneous hybrids of these species (C. × macrocarpa, C. × media, C. × subsphaericea). Contrast analysis revealed that a majority of the pollen features of hybrid species were characterized by significantly higher mean values than those of parental species. Analysis of pollen shape classes indicated that the parental species clearly differed from each other in contrast with hybrids, which were characterized by a similar proportion of pollen in individual pollen shape classes. Statistical analyses showed that the pollen grains of two parental species, C. laevigata and C. monogyna, were most similar to one another. Pollen grains of typical C. rhipidophylla were similar to the pollen of hybrids and the mean values of almost all studied pollen features [P, E, Exp, Exp/P, Le, d, d/E (PAI)] of C. rhipidophylla var. rhipidophylla were intermediate between those of C. monogyna and C. rhipidophylla var. lindmanii. This corroborates Zieliński's conjecture that C. rhipidophylla is probably an old, conserved hybrid between C. monogyna and C. calycina (= C. lindmanii = C. rhipidophylla var. lindmanii). According to the analysis of canonical variables, C. × macrocarpa and C. × media pollen grains were most similar. C. × subsphaericea and C. rhipidophylla var. rhipidophylla and C. rhipidophylla var. lindmanii formed another pair (group), and C. monogyna and C. laevigata constituted separate ‘single species groups’. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 00, 000–000.

Subfamily Ixoroideae is one of three major lineages in Rubiaceae, with approximately 4000 species. Previous molecular phylogenetic studies have indicated that many genera and tribes previously placed in other subfamilies are better considered as part of Ixoroideae. However, the internal resolution and clade support have generally been low, and several genera found to be nested in the subfamily do not appear to be associated with any described tribe. In order to resolve the phylogeny and assess the tribal delimitations in the expanded Ixoroideae, phylogenetic reconstructions were performed using Bayesian and parsimony analyses of six plastid DNA regions and a broad sampling of genera from all tribes of the subfamily. In the inferred phylogenetic hypotheses, the tribal relationships were mostly well supported, with Ixoroideae consisting of the Coffeeae and the Vanguerieae alliances as sister groups and a grade comprising Condamineeae, Henriquezieae, Posoquerieae, Retiniphylleae, Sipaneeae and the genus Steenisia. A revised tribal classification, including the description of five new tribes, Airospermeae, Augusteae, Scyphiphoreae, Steenisieae and Trailliaedoxeae, is provided. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, ●●, ●●–●●.

Colchicaceae (Liliales) comprise c. 250 species and 15–21 genera of rhizomatous or cormous perennials and are distributed through temperate and tropical Africa, Europe, Asia and North America. They have been traditionally divided into two subfamilies, but this division is still unclear and the phylogenetic relationships among members of the family and the sister relationships of the family have been debated. Moreover, it is uncertain whether the expanded circumscription of Colchicum, Gloriosa and Wurmbea to include Androcymbium, Littonia and Onixotis plus Neodregea, respectively, is unavoidable. In this study, sequences of three plastid genes, atpB, matK and rbcL, were analysed to reconstruct phylogenetic relationships in Colchicaceae. The matK region was the most variable and provided the most potentially parsimony-informative sites. We also conducted molecular phylogenetic analyses using the combined data with sequences for three non-coding regions generated by Vinnersten and Reeves. Our results strongly support the monophyly of Colchicaceae and the redefined circumscription to include two subfamilies, Wurmbeoideae and Uvularioideae. The Uvularia-Disporum clade, i.e. Uvularioideae, is sister to the rest of Colchicaceae and differentiated from Burchardia, previously suggested to be sister to the rest of Colchicaceae. In our analysis, Burchardia is placed in Wurmbeoideae. A close relationship between Tripladenia and Schelhammera was strongly supported and these are transferred to Wurmbeoideae from Uvularioideae. The six tribes sensu Vinnersten and Manning were shown to be monophyletic. Our results support the expanded circumscription of Colchicum (including Androcymbium) and Gloriosa (including Littonia), but the circumscription of Wurmbea and related genera requires further study. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172, 255–269.

We investigated the phylogenetic relationships in Tulipa in Turkey using DNA sequences from the plastid trnL-trnF region and the internal transcribed spacer (ITS) of nuclear ribosomal DNA. We generated trnL-trnF and nuclear ITS sequences for 11 Tulipa spp. from Turkey and compared the utility of trnL-trnF and ITS sequences for phylogenetic analysis. Neighbor-joining, Bayesian and maximum parsimony methods were implemented using the same matrices. Our study of Tulipa based on molecular data revealed congruent results with previous studies. Despite the relatively lower resolution of trnL-trnF than that of ITS, both sequence matrices generated similar results. Three clades were clearly distinguished, corresponding to subgenera Tulipa, Eriostemones and Orithyia. It is not fully resolved whether Clusianae should be recognized as a separate section of subgenus Tulipa or a distinct subgenus. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172, 270–279.

Tulipa (tulips; Liliaceae) is a genus of geophytes comprising c. 76 species, occurring from southwestern Europe and North Africa to Central Asia. The taxonomy and classification of the genus have been contentious in the past. We investigated the phylogenetic relationships in the genus using DNA sequences from five plastid regions (trnL intron and trnL–trnF spacer, rpl16 intron, rps12–rpl20 intergenic spacer and matK) and the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. Amana and Erythronium were used as outgroups. Sequences were obtained from 25 Tulipa taxa representing all major lineages previously identified as distinct and four outgroups (two Amana spp. and two Erythronium spp.). In the combined maximum parsimony analysis, Tulipa was strongly supported as monophyletic and four clearly defined clades in the genus were obtained, although the relationships between them were unclear. In support of previous molecular studies, the results suggest that section Clusianae should be excluded from subgenus Tulipa and accepted at subgeneric rank. Subgenus Eriostemones and subgenus Tulipa (excluding Clusianae) were both strongly supported. Tulipa sprengeri, traditionally placed in subgenus Tulipa, was shown to be a member of Eriostemones. Orithyia, in this study represented by T. uniflora, formed a fourth lineage, also to be treated at subgeneric level. In the Bayesian analysis, the genus Tulipa was strongly supported and the same four lineages (subgenera) were identified. In this case, Orithyia was sister to the rest of the genus (with moderate support) and subgenera Clusianae and Eriostemones together formed a clade with strong support. Original species descriptions and type specimens of as many names as possible were reviewed and, on this basis, a revised checklist with full synonymy, typification and distribution is provided. The status of T. ×gesneriana and its synonyms is discussed. All accepted species are classified into the four subgenera supported by our phylogenetic study. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172, 280–328.

Epidendrum is one of the largest Neotropical genera of Orchidaceae and comprises approximately 1500 species. Only 2.8% of these species have been studied cytologically, demonstrating chromosome numbers ranging from n = 12 in E. fulgens to n = 120 in E. cinnabarinum. The present work evaluated the evolution of the karyotypes of Epidendrum spp. based on data gathered from the literature and from analyses of the karyotypes of 16 Brazilian species (nine previously unpublished). The appearance of one karyotype with n = 12 with one larger chromosome pair in subgenus Amphiglottium appears to have occurred at the beginning of the divergence of this lineage, and x = 12 probably represents the basic number of this subgenus. Epidendrum secundum exhibits wide variation in chromosome numbers, with ten different cytotypes found in 22 Brazilian populations, seven of which were new counts: 2n = 30, 42, 50, 54, 56, 58 and 84. Most lineages of Epidendrum seem to have been secondarily derived from one ancestral stock with x = 20, as is seen in the majority of the present-day representatives of the genus. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172, 329–344.

The geographical distribution, population structure and pollination ecology are key aspects in the conservation and management of rare orchids. Here, we address these aspects and the main threats affecting the endangered Cuban orchid Broughtonia cubensis. This rewardless orchid is self-compatible, but pollinator dependent. However, seed production can be negatively affected by insect-mediated selfing. Three species of small bee (genera Ceratina and Lasioglossum) act as pollinators. As in the case of other nectarless orchids, we detected two species of plant producing large amounts of nectar in the area, the floral morphology of which closely resembles that of B. cubensis. The simultaneous flowering of these species could positively affect the reproductive success of B. cubensis. Nonetheless, the fitness of this orchid in natural conditions is low, possibly related to strong pollen limitation. To the problems arising from reduced fitness is added the fact that its historical distribution range has been greatly reduced in recent years. Throughout this study, we have detected dramatic reductions in the population sizes, in some cases as a result of human plundering, but also as a consequence of hurricanes. Based on the results of this study, we propose some guidelines to manage and conserve this orchid. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172, 345–357.

The systematically difficult genus Epipactis (Orchidaceae) is often subdivided into two sections: Epipactis and Arthrochilium. Until now, the latter has attracted much less taxonomic attention than the former, but here we reassess the alleged distinction of two rare and nationally endangered taxa from tropical Asia (E. flava, E. atromarginata), based on morphological examination of live plants in situ in northern Thailand and of herbarium specimens from the entire range of the complex (Thailand, Laos and Vietnam). As the variation in vegetative and floral dimensions, flower colour and labellum morphology broadly overlaps between the two taxa, we merge them under the oldest valid name at species level, E. flava. Geomorphological features of our three study sites in Thailand and high shared occurrence of previously confirmed rheophytes among the accompanying species indicate that E. flava is itself rheophytic (a very rare feature in the Orchidaceae). Possible adaptations of E. flava to its rheophytic lifestyle are discussed. Among these, the formation of pure stands through dense clonal growth involving a creeping rhizome places E. flava as a ‘mat-rooted rheophytic landplant’ (sensu van Steenis). Combining taxonomic, distributional and ecological data, we discuss the occurrence of this stream-inhabiting Epipactis in a conservation context. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172, 358–370.

The anatomy and morphology of leaves in Carex have the potential to be taxonomically useful. However, studies on the variability of leaf characteristics in the genus are sparse. Researchers therefore risk using leaf anatomical characters without the knowledge of whether they are consistent in a species. We examined 22 qualitative and seven quantitative leaf anatomy characters from transverse leaf sections to test their consistency across 11 Carex spp. The characters were clearly described and primarily microscopic. Some characters were found to exhibit high levels of intraspecific variation, whereas other characters exhibited high levels of consistency in a species, including the shape of the leaf section, the density of papillae and the size of epidermal cells. Caution must be applied when choosing leaf anatomy to delimit taxa because of the intraspecific variability found in some characters, but sufficient numbers of invariant characters exist to provide useful taxonomic separation. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172, 371–384.

Pollinators have long been known to select for floral traits, but the nature of this relationship has been little investigated in trap pollination systems. We investigated the trapping devices of 15 Arum spp. and compared them with the types of insects trapped. Most species shared a similar general design of trap chamber walls covered in downward-pointing papillate cells, lacunose cells in the chamber wall and elongated sterile flowers partially blocking the exit of the trap. However, there was significant variation in all these morphological features between species. Furthermore, these differences related to the type of pollinator trapped. Most strikingly, species pollinated by midges had a slippery epidermal surface consisting of smaller papillae than in species pollinated by other insects. Midge-pollinated species also had more elongated sterile flowers and tended to have a larger lacunose area. We conclude that pollination traps evolve in response to the type of insect trapped and that changes to the slippery surfaces of the chamber wall are an important and previously little recognized variable in the design of pollination traps. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172, 385–397.