Showing papers in "Plant Ecology and Evolution in 2020"

New insights on spatial genetic structure and diversity of Coffea canephora (Rubiaceae) in Upper Guinea based on old herbaria

Abstract: Backgrounds and aims – Previous studies showed that robusta coffee (Coffea canephora Pierre ex A.Froehner), one of the two cultivated coffee species worldwide, can be classified in two genetic groups: the Guinean group originating in Upper Guinea and the Congolese group in Lower Guinea and Congolia. Although C. canephora of the Guinean group is an important resource for genetic improvement of robusta coffee, its germplasm is under-represented in ex situ gene banks and its genetic diversity and population structure have not yet been investigated. Methods – To overcome the limitations of living collections, we explored old herbarium specimens collected in Guinea and Cote d'Ivoire and conserved at the Museum National d'Histoire Naturelle, Paris. First, we reviewed the history of collection missions in both countries and how the C. canephora herbaria from the Museum were assembled. Then, using 23 nuclear microsatellite markers, factorial and model-based Bayesian analyses, we investigated the genetic diversity of 126 specimens and 36 controls, analysed their distribution among the Congolese and Guinean groups, and estimated admixture proportions for each individual. Key results – For the first time, we detected population genetic structure within the Guinean group of C. canephora. The Guinean genotypes can be assigned to five sub-groups with distinct geographic distribution, especially in Guinea where two sub-groups (Maclaudii and Game) are characterized by a low level of admixture due to geographical isolation. Conclusions – We showed how combining a literature review and genetic data from old herbarium specimens can shed light on previous observations made by botanists and guide further actions to better preserve native coffee plants in forest remnants of West Africa.

The hyperdominant tropical tree Eschweilera coriacea (Lecythidaceae) shows higher genetic heterogeneity than sympatric Eschweilera species in French Guiana

Abstract: Background and aims – The evolutionary history of Amazonia’s hyperabundant tropical tree species, also known as “hyperdominant” species, remains poorly investigated. We assessed whether the hyperdominant Eschweilera coriacea (DC.) S.A.Mori (Lecythidaceae) represents a single genetically cohesive species, and how its genetic constitution relates to other species from the same clade with which it occurs sympatrically in French Guiana. Methods – We sampled 152 individuals in nine forest sites in French Guiana, representing 11 species of the genus Eschweilera all belonging to the Parvifolia clade, with emphasis on E. coriacea. Samples were genotyped at four simple sequence repeat (SSR) markers. We delimited gene pools, i.e., genetically coherent putative taxa, using STRUCTURE software and principal component analysis. We compared the genetic assignment of individuals with their morphological species determination and estimated genetic diversity and differentiation for gene pools and species. We also estimated genome size using flow cytometry. Key results – SSR profiles commonly displayed up to four alleles per genotype, suggesting that the investigated Eschweilera species bear a paleopolyploid signature. Flow cytometry suggested that the studied species are diploid with haploid genome sizes of 871–1046 Mbp. We detected five gene pools and observed a good correspondence between morphological and genetic delimitation for Eschweilera sagotiana Miers and the undescribed morphospecies E. sp. 3 (which resembles E. grandiflora (Aubl.) Sandwith), and to a lesser extent for E. decolorans Sandwith and E. micrantha (O.Berg) Miers. Eschweilera coriacea was the most genetically diverse species and included individuals assigned to each gene pool. Conclusions – We found no conclusive evidence for cryptic species within E. coriacea in French Guiana. SSRs detected fewer gene pools than expected based on morphology in the Parvifolia clade but discriminated evolutionary relationships better than available plastid markers. A positive trend between demographic abundance of species and allelic richness illustrates that hyperdominants may have a high evolutionary potential. This hypothesis can be tested using more powerful genomic data in combination with tree phenotypic trait variation and characterization of niche breadth, to enhance our understanding of the causes of hyperdominance in Amazonian trees.

Notes on the plants of Bakossi, Cameroon, and the new Cola etugei and Cola kodminensis (Sterculiaceae s. str.)

Abstract: Background and aims – This paper reports a further discovery during preparation for a monograph of the genus Cola, and also in the context of a long-term botanical survey in the Cross River-Sanaga interval of west-central Africa, focussing on species discovery and conservation through the Tropical Important Plant Areas programme. Methods – Normal practices of herbarium taxonomy have been applied to study the material collected. The relevant collections are stored in the Herbarium of the Royal Botanic Gardens, Kew, London (K) and at the Institute of Research in Agronomic Development – National Herbarium of Cameroon (YA). Key results – Two species new to science, small trees or shrubs of cloud forest, are formally named from the Bakossi tribal area and assessed for their conservation status. Cola etugei, is endemic to the western slopes of Mt Kupe with conservation status assessed as Critically Endangered (CR B1+2ab(iii)) according to the 2012 criteria of IUCN. Cola kodminensis from the Bakossi Mts is also assessed as Critically Endangered (CR B1+2ab(iii)). This publication increases the number of documented narrowly endemic, threatened species in the Bakossi tribal area, and helps make the case for formal protection of Mt Kupe, which with 33 endemic and near-endemic plant species remains an extremely high candidate for such protection. Further effort is needed to publish the remaining informally named species of this location, and investment to support the protection of the mountain by local communities.

Combining the small South American genus Androtrichum into Cyperus (Cyperaceae)

Abstract: Background and aims – Molecular phylogenetic studies have provided a clearer understanding of the complex relationships within the family Cyperaceae. These studies have consistently shown that 12 allied genera are nested in the genus Cyperus. However, early Sanger sequencing-based phylogenies that included the two species of the small South American genus Androtrichum were inconclusive in placing this genus either as sister to Cyperus or as part of its early divergent lineages. A recent phylogenetic analysis however conclusively placed the two species of Androtrichum within the C3 Cyperus Grade. In this study, we investigate if the morphology and anatomy of Androtrichum species provide additional evidence for their placement in the genus Cyperus. In addition, we provide descriptions and distribution data for the species. Material and methods – Herbarium material from FLOR, FURB, GENT, ICN, and K has been studied. Samples of the culm and leaf were studied using histological methods. Taxonomic changes and typifications of names were performed according to the International Code of Nomenclature for algae, fungi, and plants. Key results – The morphology and the non-Kranz anatomy observed in the Androtrichum species confirm their placement among the other C3 Cyperus species. Androtrichum is combined into Cyperus. For one species, a combination in Cyperus is already available: Cyperus trigynus. For the other species, a new name in Cyperus is published: Cyperus byssaceus. Two typifications are established and morphological descriptions and distribution data are provided. Conclusion – By integrating recent molecular phylogenetic data with additional evidence from morphology and anatomy, Androtrichum is combined into Cyperus. As a result of this taxonomic change, a single monophyletic genus Cyperus is now recognised in the Cyperus Clade of tribe Cypereae.

Notes on Tricalysia elmar sp. nov. (Rubiaceae, Coffeeae), and cloud forest of the Cameroon Highlands

Abstract: Background and aims – This paper reports a further discovery in the context of a long-term botanical survey in the Cross River-Sanaga interval of west-central Africa, focussing on species discovery and conservation. Methods – Normal practices of herbarium taxonomy have been applied to study the material collected. The relevant collections are stored in the Herbarium of the Royal Botanic Gardens, Kew, London and at the Institute of Research in Agronomic Development – National Herbarium of Cameroon. Key results – Species new to science recently discovered from the cloud (submontane) forests of the Cameroon Highlands in Cameroon are reviewed. Most of these species are rare, highly localised, and threatened by habitat destruction. These discoveries increase the justification for improved conservation management of surviving habitat. Tricalysia elmar Cheek (Coffeeae-Rubiaceae) is described as an additional cloud forest species new to science. Its taxonomic position is discussed, and it is compared with similar species of the genus. Restricted so far to four locations, Mt Kupe, Bali Ngemba, Lebialem and Nta Ali, its conservation status is assessed as Endangered (EN B1+2ab(iii)) according to the 2012 criteria of IUCN.

Different ways to obtain similar results: the development of the corolla and epipetaly in Rubieae (Rubioideae, Rubiaceae)

Abstract: Background and aims – Rubieae is a tribe in the subfamily Rubioideae characterised by herbaceous plants with verticillate leaves and flowers with a rudimentary or absent calyx and a short, cup-shaped corolla. This is in contrast to the flowers of most other Rubiaceae, in which the tubular corolla is longer than the corolla lobes. Also, the description by Payer, a French 19th century pioneer of floral ontogenetic research, of the floral development in Asperula, Galium, and Rubia deviates from recent insights about the development of tubular corollas, which are based on investigations of flowers of tropical Rubiaceae. Tubular corollas are currently considered as resulting from the development of underlying annular intercalary meristems, whereas Payer explained the tubular corollas in the three taxa by postgenital fusion. We therefore tested both hypotheses in six Rubieae genera, including the three taxa studied by Payer. Methods – Floral ontogeny of ten species in six Rubieae genera based on scanning electron (SEM) and light microscopy (LM). Conclusions – Our results suggest that, in all species studied, the mature phenotype of the corolla as well as the epipetaly of the stamens is caused by a combination of three developmental processes (the development of a stamen-corolla tube, the development of a corolla tube sensu stricto, and postgenital fusion), and the relative moment of activation of each of these processes during floral development (plastochron variation or heterochrony).

Diversity of epiphyte ferns along an elevational gradient in El Triunfo Biosphere Reserve, southern Mexico

Abstract: Background and aims – In the tropics, some studies have found that the richness of epiphytic ferns present a peak at mountain mid-elevations. However, it is not well understood how transitions from tropical to subtropical conditions affect this peak, and even less is known about beta diversity of epiphytic ferns. Thus, the objective is to understand the effect of climatic gradients on the variation of local richness of ferns and beta diversity patterns along an elevational gradient in a mountain system in southern Mexico.Methods – We sampled 32 trees, each in four elevational bands (100–2200 m). Alpha diversity patterns were analysed using linear regression models. We used the Morisita index to quantify species turnover between bands. An additive partitioning approach was used to analyse the degree to which individual trees, plots, and bands contributed to total species richness. We evaluated the influence of climatic variables on species composition via linear regression models.Key results – A total of 30 species in five families were recorded. Each family contributed in different magnitude to the elevational richness pattern, with Polypodiaceae dominating due to its richness and presence along the entire transect. Alpha diversity at the three scales (αtree, αplot, αband) increased with elevation and rainfall, and with decreasing temperature. Species turnover was high along the gradient, but was scale-dependent, with βtransect (65–75%) and βband (14%) with the greatest contributing to total diversity. Although the contribution of the individual trees was lower, it increased with elevation. Conclusions – We emphasize the importance of including different scale levels in analyses of diversity along elevational gradients. In the region, cloud forest on the mountain peaks harbours the highest diversity of epiphytic fern communities. Due to a limited extent of this mountain range, the epiphyte ferns are susceptible to the effects of climate change.

Typology of the woody plant communities of the Ethiopian Nech Sar National Park and an assessment of vegetation-environment relations and human disturbance impacts

Abstract: 1Department of Biology, KU Leuven, Kasteelpark Arenberg 31-2435, BE-3001 Leuven, Belgium 2Department of Forestry, College of Agriculture, Arba Minch University, P.O. Box 21, Arba Minch, Ethiopia 3Division Forest, Nature and Landscape, KU Leuven, Celestijnenlaan 200E-2411, BE-3001 Leuven, Belgium 4Department of Biology, College of Natural Science, Arba Minch University, P.O. Box 21, Arba Minch, Ethiopia *Corresponding author: kenny.helsen@kuleuven.be REGULAR PAPER

Myxomycete diversity in a humid montane forest on the eastern slopes of the peruvian andes

Abstract: Background – The humid montane forests on the eastern slopes of the Peruvian Andes are known for their high biodiversity and natural resources. While their incredibly rich plant and animal communities are still in the process of being discovered, the diversity of smaller organisms such as the Myxomycetes are even more scarcely known. In this work, we document the Myxomycete diversity in these montane forests and evaluate species abundance, occurrence by substrates, distribution, and seasonality, thus documenting population status and species ecology. Material and methods – The study was carried out at the Wayqecha Biological Station located in the Cusco region of Peru. Two sampling campaigns took place in late January (wet season) and early May (dry season) of 2018. We performed a species inventory and evaluated alpha diversity, assemblage similarity, and abundance of Myxomycetes within six 100 m2 plots. We documented variations of species richness and abundance between seasons as well as between substrates. Results – We recorded a total of 81 taxa of Myxomycetes. The order Physarales was the most diverse, and the most abundant species were Didymium squamulosum and Diderma deplanatum during the wet and dry season, respectively. The substrate with highest diversity overall was dead leaves. Diversity was similar in both seasons but with a notable species turnover. Conclusion – The humid montane forest on the eastern slopes of the Andes in Peru revealed an unexpected richness in Myxomycetes. Based on our results, we conclude that this type of forest harbours one of the greatest Myxomycetes diversities in the Peruvian territory, also due to the important seasonal species turnover.

New insights on Bjerkandera (Phanerochaetaceae, Polyporales) in the Neotropics with description of Bjerkandera albocinerea based on morphological and molecular evidence

Abstract: Fil: Motato-Vasquez, Viviana. Nucleo de Pesquisa Em Micologia, Instituto de Botânica; Brasil

A new species of Drypetes (Putranjivaceae) discovered by J. Léonard in the Democratic Republic of the Congo

Abstract: Background – During his stay in Yangambi in the 1940s, the Belgian botanist J. Léonard collected a species of the genus Drypetes endemic to the Democratic Republic of the Congo. He named it D. morocarpa on herbarium labels, but never published it. Methods – The present study is based on the revision of 26 collections of D. morocarpa. Morphometric measurements on herbarium specimens belonging to the new species and its closest relatives in Drypetes were carried out in order to describe this new species. Results – We describe here D. morocarpa J.Léonard ex D.J.Harris & Quintanar. It is easily recognisable by its blackish twigs and young branchlets, orbicular stipules, leaf blades usually entire, and hard fruits, covered with irregular protuberances. It has been collected in two areas along the course of the Congo river or its tributaries. A differential diagnosis, a detailed morphological description, a key to distinguish it from the most similar species, an illustration and all the available information about its habitat, distribution and conservation status are provided.

Further new species and records from the coastal dry forests and woodlands of the Rovuma Centre of Endemism – Erratum

Abstract: 1Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, UK 2Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK 3Honorary Research Associate, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, UK 4Instituto de Investigação Agrária de Moçambique (IIAM), P.O. Box 3658, Mavalane, Maputo, Mozambique 5Buffelskloof Herbarium, Buffelskloof Nature Reserve, P.O. Box 710, Lydenburg, Mpumalanga Province 1120, South Africa *Corresponding author: i.darbyshire@kew.org REGULAR PAPER

Cordia subcordata (Boraginaceae), a distylous species on oceanic coral islands, is self-compatible and pollinated by a passerine bird

Abstract: Background and aims – Distyly is usually rare on oceanic islands, which is probably due to the difficulty for distylous plants to colonize those islands. However, Cordia subcordata was observed to be distylous with shortand long-styled morphs on the Xisha Islands in the South China Sea. To characterize the reproduction system of Cordia subcordata and to understand how this distylous species maintains itself on these islands, we studied its reproductive and pollination biology. Methods – Seed set and pollen tube growth under manipulated intermorph, intramorph, and self-pollination were examined to investigate self-incompatibility in the species. The number of pollen grains deposited on the stigmas after a single pollinator visit were counted to investigate the pollination efficiency of different visitors. Key results – Our study indicated that Cordia subcordata shows reciprocal herkogamy as is typical in distylous species. Pollen tubes could reach the base of the style and move into the ovules under all the manipulated pollination treatments in both morphs. Seed set resulting from four hand-pollination experiments did not show any differences between both morphs, suggesting that Cordia subcordata lacks heterostylous self-incompatibility. The most frequent flower visitors, Zosterops japonicus and Apis cerana, were observed foraging on the large volumes of nectar and pollen grains, respectively, with Zosterops japonicus being the most effective pollinator, depositing large number of pollen grains on the stigmas during their visits. Conclusions – Our findings show that Cordia subcordata established itself and persists in the archipelago by producing fruits through a combination of self-compatibility and pollination by the most common passerine bird on the oceanic islands.

Un nouveau Cynorkis (Orchidaceae) pour la flore des Mascareignes

Abstract: Contexte et objectifs – Lors de la révision taxonomique du genre Cynorkis (Orchidaceae) aux Mascareignes, un nouveau taxon collecté à La Réunion a été découvert et est officiellement décrit ici.Matériel et méthodes – Une comparaison de 312 spécimens (conservés dans les herbiers de P, MAU et REU) des Mascareignes avec les types nomenclaturaux a été entreprise afin de confirmer le statut taxonomique du nouveau taxon. Son état de conservation a été évalué selon les Catégories et Critères de la Liste Rouge de l’UICN.Principaux résultats – Cynorkis borbonica Pailler sp. nov. est décrit et illustré. Il est endémique de La Réunion où il se trouve dans les écosystèmes naturels à plus de 1900 m au-dessus du niveau de la mer. Son habitat est principalement le maquis dominé par Erica borbonica où il se rencontre sur le sol dans un tapis de bryophyte. Cynorkis trilinguis est la seule espèce proche et en diffère morphologiquement par la forme de son éperon et par la forme des feuilles. D’un point de vue de la distribution altitudinale, C. borbonica se développe à des altitudes supérieures à C. trilinguis. L’espèce est considérée comme En Danger selon les catégories et critères de l’UICN. A new Cynorkis (Orchidaceae) for the flora of the Mascarene Islands Background and aims – While conducting a taxonomic revision of the genus Cynorkis (Orchidaceae) in the Mascarenes, a new species collected in La Réunion was discovered and it is formally described here.Material and methods – A comparison of about 312 specimens (housed at P, MAU, and REU herbaria) from Mascarenes with nomenclatural types was undertaken in order to confirm the taxonomical status of the new species. Its conservation status was assessed using the IUCN Red List Categories and Criteria. Key results – Cynorkis borbonica Pailler sp. nov. is here described and illustrated. It is endemic to La Réunion where it is found in natural ecosystems at an elevation of more than 1900 m a.s.l. Its habitat is mainly shrubland dominated by Erica reunionensis where it grows on the ground in bryophyte mats. The only morphologically close species is Cynorkis trilinguis but it differs from the latter by its spur and leaf, as well as growing at a higher elevation. The species is considered as Endangered according to the IUCN Red List Categories and Criteria.

Eugen Warming’s Florula Lagoensis revisited: old lessons to new challenges

Abstract: Background and aims – We revisited Florula Lagoensis, the first floristic list of the Cerrado, published in 1892 by Eugen Warming. All flowering plants were nomenclaturally and taxonomically updated and associated with type material collected by him. We also analysed the contribution of new collections made in Lagoa Santa to assess how many species were recollected after his work. Methods – We have used the list of phanerogams in Warming’s 1908 translation as primary data source and we performed a search on Brazilian virtual herbaria to retrieve all material collected at the locality of Lagoa Santa and surroundings. Key results – Out of 2270 species collected by Warming, 560 (24.7%) have been recollected after 150 years, and only 242 species (9.6%) were new additions to the list. A total of 381 (14.4%) specific or infraspecific names from Florula Lagoensis have type specimens collected by Warming. Conclusions – It is fair to recognize Eugen Warming as one of the pioneers of floristic studies in Brazil. We stress the completeness of his work and highlight the importance of following Warming’s footsteps, collecting intensively, exploring different environments, and working in a collaborative way.

Effects of heathland management on seedling recruitment of common juniper (Juniperus communis)

Abstract: Background and aims – Common juniper (Juniperus communis L.) is one of the most widespread woody species on the planet. Over recent decades, however, common juniper populations are decreasing in size and number in different regions. Lack of recruitment, caused by extremely low seed viability and the absence of suitable microsites for recruitment, is the key reason for this decline. For successful germination, the seeds need gaps in the existing vegetation and a soil with a relatively high base saturation. The aim of this study was therefore to assess how management actions such as sod cutting, rotavation and liming (alone or in various combinations) influence soil characteristics, seed germination and seedling survival of common juniper. Methods – We installed a sowing experiment across 104 1-m2 plots in four different sites in Belgium and the Netherlands using treatments with different combinations of fencing, sod cutting, rotavation, litter addition and liming. We determined how these treatments affected soil characteristics and how they influenced seed germination and seedling survival. Key results and conclusions – Across the whole experiment, germination rates of juniper seeds were very low (almost always

Patterns in the alien flora of the Democratic Republic of the Congo: a comparison of Asteraceae and Fabaceae

Abstract: Background and aims – This work provides the first pattern analysis of the alien flora of the Democratic Republic of the Congo (D.R. Congo), using Asteraceae and Fabaceae as a case study. Methods – Based on herbarium collections, existing databases, and literature data, a database of 38 alien species of Asteraceae and 79 alien species of Fabaceae has been assembled. Patterns in the introduction pathway, phylogeny, life form, morpho-functional traits, geographic origin, and occurrence in D.R. Congo are explored. Key results – America is the main source continent in both families, but Asia is also an important donor of Fabaceae. Taxonomic spectrum discrepancies between the alien and the native flora reflect the continent of origin. Sixty-six percent of alien Asteraceae have been accidentally introduced, most of which being annual weeds of disturbed soil. In contrast, 90% of alien Fabaceae have been deliberately introduced for forestry, agriculture, or environmental purposes, most of which being phanerophytes. Traits were compared between pairs of congeneric alien and native species. For Asteraceae, a sharp discrepancy was found in the life form spectrum (aliens: mostly therophytes; natives: phanerophytes). For Fabaceae, alien species had larger leaves and larger pods compared to their native congeners. The number of specimens in collections was positively correlated with the time since the date of first collection for both families. The GuineoCongolian region has the highest number of alien Fabaceae, while alien Asteraceae are overrepresented in the Zambezian region. Conclusions – Contrasting patterns between alien Asteraceae and Fabaceae in the flora of D.R. Congo in terms of life forms, trait divergence compared to the native flora, and occurrence, reflect the divergent biological attributes and relations to humans of the two families. The striking discrepancies between the two families call for analyses of patterns of alien flora at family level and warn against global generalisations.

New records for the flora of Angola: observations from Uíge and Cuanza Norte

Abstract: Background and aims – Located in the transition zone of Guineo-Congolian and Zambezian phytochoria, the Angolan provinces of Uíge and Cuanza Norte are of particular interest for floristic studies and high biodiversity is expected. Nevertheless, explorations of the vegetation are relatively rare. Our study aims to supplement a recent checklist of vascular plants of Angola. Methods – Data were collected during 17 field trips between 2013 and 2018, during which herbarium specimens were prepared for later identification of plant species. The results were compared with the current checklist as well as with other floristic works, herbarium collections and online databases relevant for the region. Key results – We document 20 new records of indigenous vascular plant species for the flora of Angola (19 species and one subspecies), including four new generic records. Furthermore, nine alien species are added to the checklist of the flora of Angola. Conclusion – Our results confirm that the flora of northern Angola is composed by elements of various adjacent areas. However, not all species present are known yet. Further botanical investigation is needed to complete our floristic knowledge of the region.

Dracula’s mistress: removal of blood-red floral nectar results in secretion of more nectar

Abstract: Background and aims – Flowers of Jaltomata quipuscoae (Solanaceae) secrete blood-red nectar that serves as an energy reward and possible attractant to pollinators. The purposes of this study were to determine whether simulated pollinator visits (manual removal of nectar) stimulates replenishment of nectar, and report the pattern of nectar presentation during the lifespan of the flower. Methods – For the nectar replenishment experiments flowers were paired: each pair of flowers was selected to be on the same plant and at the same developmental stage. From all 62 flowers nectar was removed and discarded (not measured) at time zero. Then, over a period of eight hours, the nectar of one flower was measured four times, i.e., every two hours, while nectar of the paired control flower was measured only at the end of the eight-hour period. In the nectar dynamics experiment five sets of flowers received different treatments: flowers were unmanipulated for zero, one, two, three or four days and then nectar was removed once every day. The volume of nectar produced and concentration of sugar in the nectar were recorded at each extraction for both studies. Key results – In the nectar replenishment study significantly higher nectar volume and consequently significantly higher total sugar content was present in the experimental nectar-extracted flowers. In the nectar dynamics study, nectar was produced starting on day one or two, continuously through the life of the open flowers until one or two days before the corolla senesced. Delay of nectar removal from different flower sets for zero, one, two, three or four days resulted in a linear increase in nectar volume and total nectar sugar production, and had little or no effect on the cumulative (life of the flower) nectar production. Floral longevity, seven to ten days, was not affected by a single removal of nectar each day. Conclusions – The floral nectary of J. quipuscoae responded to nectar removal by secreting more nectar, and thus more total sugar (not a higher concentration of sugar) than was secreted by control flowers. In flowers from which nectar was not removed, nectar volume and thus total sugar secreted continued to accumulate linearly, suggesting that reabsorption of nectar either does not occur or is slow relative to the rate of secretion. The more we (or pollinators) take, the more the flowers make: the volume of nectar and sugar production increase if nectar is removed frequently but not if nectar is removed infrequently.

Natural intraspecific trait variation patterns of the wild soursop Annona senegalensis (Annonaceae) along a climatic gradient in Benin, West Africa

Abstract: 1Laboratoire de Biomathématiques et d’Estimations Forestières, Faculty of Agronomic Sciences, University of Abomey-Calavi, 04 BP 1525 Cotonou, Republic of Benin 2Laboratory of Applied Ecology, Faculty of Agronomic Sciences, University of Abomey-Calavi, 05 BP 1752 Cotonou, Republic of Benin *Corresponding author: hounkpeviachille@gmail.com ‡These authors contributed equally to this work REGULAR PAPER

Two new Critically Endangered species of Ditassa (Apocynaceae) from the threatened cangas of the Iron Quadrangle, Minas Gerais, Brazil

Abstract: 1Programa de Pós-Graduação em Botânica, Universidade Estadual de Feira de Santana, Av. Transnordestina, s/n, Novo Horizonte, 44036-900, Feira de Santana, Bahia, Brazil 2Departamento de Biologia, Centro de Ciências, Universidade Federal do Ceará, Av. Mister Hull s/n, campus do Pici, 60440-900, Fortaleza, Ceará, Brazil 3Centro de Formação em Tecnociências e Inovação, Universidade Federal do Sul da Bahia, Rua Itabuna, s/n, Rod. Ilhéus – Vitória da Conquista, km 39, BR 415, Ferradas, 45613-204, Itabuna Bahia, Brazil *Corresponding author: rapinibot@yahoo.com.br REGULAR PAPER

Niche conservatism in a plant with long invasion history: the case of the Peruvian peppertree (Schinus molle, Anacardiaceae) in Mexico

Abstract: 1IPICYT/División de Ciencias Ambientales, Camino a la Presa San José 2055, Colonia Lomas 4a Sección, C.P. 78216, San Luis Potosí, San Luis Potosí, México 2Museo de Zoología “Alfonso L. Herrera”, Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Apartado Postal 70-399, C.P. 04510, Ciudad de México, México 3Laboratory for Research in Environmental Sciences (LARES), Faculty of Agricultural Sciences, Department of Environmental Sciences and Natural Renewable Resources, University of Chile, Av. Santa Rosa 11315, La Pintana, Santiago, Chile 4Departamento de Ciencias Ecológicas Instituto de Ecología y Biodiversidad, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Santiago, Chile *Corresponding author: ernesto.badano@ipicyt.edu.mx REGULAR PAPER

Checklist of vascular plants for Wind River Indian Reservation (USA) high-elevation basins: ecological drivers of community assemblages

Abstract: Background and aims – Native American reservations in the United States provide biodiversity critical for conservation and ecosystem functions. Unfortunately, botanical inventories are less common for reservations than other land jurisdictions. Such ecological importance and needs are apparent for the Wind River Indian Reservation (WRIR), the 7th largest reservation in the US (>890,000 ha) that is shared by the Eastern Shoshone and Northern Arapaho. Material and methods – A botanical study for two WRIR high-elevation basins (Saint Lawrence Basin (SLB) and Paradise Basin (PB)) to (1) reconcile a 1960 plant list, and (2) quantify plant communities ecologically was conducted. In 2017, 106 monitoring sites were established to quantify species presence. Across basins, 231 total vascular plant taxa (221 to species and 10 to genus) were identified, or > 3× more plant species than noted in the 1960 list. In SLB, 222 plant taxa (213 to species and 9 to genus) were identified and in PB 98 plant taxa (90 to species and 8 to genus) were identified. In 2018, sites were re-sampled to quantify species abundance, soil pH, organic matter, soil nutrients, CEC, salts, and texture. Key results – Slope and elevation explained species distributions in the topography ordination and soil organic matter, pH, texture, P, and K explained species distributions in the soil ordination. Eleven exotic species, and one rare endemic species were documented with implications for empowering tribal management. Using a classification approach followed by an indicator species analysis and fidelity (Phi) assessment, we identified 14 unique plant communities and related these to 6 alliances and 7 associations across 6 macrogroups from the US National Vegetation Classification database. These indicator species of communities included sedges (Carex aquatilus), grasses (Pseudoroegneria spicata, Elymus elymoides, Achnatherum lettermanii, Elymus trachycaulus subsp. trachycaulus, Poa glauca subsp. rupicola), forbs (Polygonum bistortoides, Balsamorhiza incana, Castilleja flava), shrubs (Artemisia tridentata, Betula glandulosa, Dasiphora fruticosa subsp. floribunda) and trees (Pinus contorta). Conclusion – The plant taxa, plant communities, and ecological drivers documented in this study will enhance tribal and federal monitoring of these high-elevation WRIR basins.

Seasonality drives herbaceous community beta diversity in lithologically different rocky outcrops in Brazil

Abstract: 1Centro Universitário Redentor, BR 356, Cidade Nova, Itaperuna, Rio de Janeiro, Brazil 2Universidade Federal de Viçosa, Department of Plant Biology, Campus Viçosa, 36570-900, Viçosa-MG, Brazil 3Universidade Federal de Viçosa, Department of Plant Biology, Laboratory of Ecology and Evolution of Plants, Campus Viçosa, 36570-900, Viçosa-MG, Brazil 4Universidade Federal de Viçosa, Department of Soil, Campus Universitário, 36570-900, Viçosa-MG, Brazil *Corresponding author: jaquelinabiologa@yahoo.com.br REGULAR PAPER

Population genetic structure and management perspectives for Armeria belgenciencis, a narrow endemic plant from Provence (France)

Abstract: Background and aims-Conserving threatened biodiversity needs a robust knowledge and delineation of the taxonomical entities targeted for in or ex situ conservation. In the genus Armeria (Plumbaginaceae), the frequent correlation between geographical isolation and morphological differentiation led to the delineation of some taxa consisting of few populations. Armeria belgenciensis is a narrow endemic represented by one population in southern France, which recently experienced a strong demographic decline caused by repeated disturbances of its habitat and was the object of a demographic rescue. Within two kilometres of A. belgenciensis, the presence of A. arenaria subsp. peirescii, also represented by one small population, poses the question whether the two populations are genetically isolated and should be considered as separated taxa for conservation. Material and methods-The genetic structure of Armeria belgenciensis and the geographically close populations of Armeria arenaria were analysed based on 328 AFLP markers using model-based and model-free clustering methods. In addition, flowering phenology was estimated to address the possibility of pre-zygotic isolation between A. belgenciensis and A. arenaria subsp. peirescii. Key results-The genetic structure supported a close relationship between A. belgenciensis and A. arenaria subsp. peirescii, compared to other populations of A. arenaria. Despite its recent decline, the genetic diversity of A. belgenciensis was not particularly low compared to the other studied populations or other rare species in this genus. The existence of gene flow between these two populations is likely given their moderate differentiation and the detection of admixture by one of the clustering methods. The phenological study showed that cross-pollination is possible during a short time period. Conclusion-We propose to place these two populations under the name A. belgenciensis, but to keep them as two different management units until there is no evidence of a harmful effect due to small effective sizes.

Two new species of Phialiphora (Spermacoceae, Rubiaceae) exemplify drought adaptations in western Madagascar

Abstract: 1Meise Botanic Garden, Nieuwelaan 38, BE-1860 Meise, Belgium 2Kew Madagascar Conservation Centre, Lot II J 131 Ambodivoanjo, Ivandry, Antananarivo, Madagascar 3Parc Botanique et Zoologique de Tsimbazaza, Antananarivo, Madagascar 4Ecology, Evolution and Biodiversity Conservation, KU Leuven, Kasteelpark Arenberg 31, P.O. Box 2435, BE-3001 Heverlee, Belgium *Corresponding author: petra.deblock@meisebotanicgarden.be REGULAR PAPER

Revision of Eulophia (Orchidaceae) in Nigeria, Cameroon, Equatorial Guinea, Gabon, and the Republic of the Congo

Abstract: Background and aims – The genus Eulophia (Orchidaceae) is revised for Nigeria, Cameroon, Equatorial Guinea, Gabon, and the Republic of the Congo. The aims are: to present a morphological characterization of the main vegetative and reproductive features of Eulophia to clarify the delimitation of the taxa within the genus in the studied countries; to provide an updated identification key and an updated checklist of the genus with nomenclatural data, distribution maps, ecological information, and preliminary conservation status. This revision may serve as a basis for future studies of the genus in other regions of Africa. Material and methods – Relevant material kept in BM, BR, FHI, HBG, K, MA, P, and WAG was examined, using standard practices of herbarium taxonomy. Vegetative and reproductive structures were analysed. MapMaker was used to produce the distribution maps. Key results – A total of 24 species are recognised in the study area. The variability of perennating organs, leaves, sepals and petals, lip (including ornamentation), spur, and anther cap are described and depicted, and were found to be informative for species recognition. A taxonomic treatment is given with an identification key, synonymy, distribution maps, preliminary conservation status, and specimen citations. Eulophia galeoloides is neotypified, E. brevipetala, E. leonensis, E. penduliflora, and Lissochilus elatus are lectotypified. According to our study, we consider E. parvula a synonym of E. pyrophila. E. sordida is considered as a doubtful species in the study area.

Englerodendron libassum (Leguminosae-Detarioideae-Amherstieae), a new Critically Endangered tree species from coastal Liberia

Abstract: Background and aims – While searching the banks of a lagoon close to Monrovia for known local endemic plant species, an unknown tree species was discovered. Its unijugate leaves allowed to quickly establish that this legume belongs to Englerodendron. This paper formally describes the finding as a new species and assesses its conservation status. Material and methods – The paper is based on data from fieldwork and morphological investigation of available herbarium material. Key results – The novelty named here E. libassum is one more endemic species from the special coastal vegetation on old beach sand. Only five mature trees were found in a relatively well-known area where not much original forest is left. The species is provisionally assessed as Critically Endangered.

Plagiochila xerophila (Plagiochilaceae, Marchantiophyta) – a highly xerophilous new species from the Tibetan Spur (China)

Abstract: Background and aims – The xeric landscapes of the Tibetan floristic province are adverse habitats for leafy liverworts. Here we report on the occurrence of a population of a species of the genus Plagiochila from exposed high-elevation cliffs in the Sichuan Province, China. We assessed its taxonomic distinctiveness and affinities within a morphological and phylogenetic framework. Results and discussion – The population is accommodated in a new species, Plagiochila xerophila Bakalin & Vilnet – probably the most xerophilous taxon within the genus in Asia – and a new section (sect. Xerophilae Bakalin & Vilnet) based on integrative analyses of molecular and morphological traits. The species is characterized by a greenish colour, unexpected given the highly exposed habitat, rigid texture and stem paraphyllia. The closest morphological relatives from sect. Poeltiae are phylogenetically only distantly related, whereas members of its sister groups, namely of sect. Trabeculatae and sect. Fruticosae are morphologically conspicuously different.