Claes Persson

Tracing the impact of the Andean uplift on Neotropical plant evolution.

Recent phylogenetic studies have revealed the major role played by the uplift of the Andes in the extraordinary diversification of the Neotropical flora. These studies, however, have typically considered the Andean uplift as a single, time-limited event fostering the evolution of highland elements. This contrasts with geological reconstructions indicating that the uplift occurred in discrete periods from west to east and that it affected different regions at different times. We introduce an approach for integrating Andean tectonics with biogeographic reconstructions of Neotropical plants, using the coffee family (Rubiaceae) as a model group. The distribution of this family spans highland and montane habitats as well as tropical lowlands of Central and South America, thus offering a unique opportunity to study the influence of the Andean uplift on the entire Neotropical flora. Our results suggest that the Rubiaceae originated in the Paleotropics and used the boreotropical connection to reach South America. The biogeographic patterns found corroborate the existence of a long-lasting dispersal barrier between the Northern and Central Andes, the “Western Andean Portal.” The uplift of the Eastern Cordillera ended this barrier, allowing dispersal of boreotropical lineages to the South, but gave rise to a huge wetland system (“Lake Pebas”) in western Amazonia that prevented in situ speciation and floristic dispersal between the Andes and Amazonia for at least 6 million years. Here, we provide evidence of these events in plants.

Estimating species diversity and distribution in the era of Big Data: to what extent can we trust public databases?

Abstract Aim Massive digitalization of natural history collections is now leading to a steep accumulation of publicly available species distribution data. However, taxonomic errors and geographical uncertainty of species occurrence records are now acknowledged by the scientific community – putting into question to what extent such data can be used to unveil correct patterns of biodiversity and distribution. We explore this question through quantitative and qualitative analyses of uncleaned versus manually verified datasets of species distribution records across different spatial scales. Location The American tropics. Methods As test case we used the plant tribe Cinchoneae (Rubiaceae). We compiled four datasets of species occurrences: one created manually and verified through classical taxonomic work, and the rest derived from GBIF under different cleaning and filling schemes. We used new bioinformatic tools to code species into grids, ecoregions, and biomes following WWFs classification. We analysed species richness and altitudinal ranges of the species. Results Altitudinal ranges for species and genera were correctly inferred even without manual data cleaning and filling. However, erroneous records affected spatial patterns of species richness. They led to an overestimation of species richness in certain areas outside the centres of diversity in the clade. The location of many of these areas comprised the geographical midpoint of countries and political subdivisions, assigned long after the specimens had been collected. Main conclusion Open databases and integrative bioinformatic tools allow a rapid approximation of large‐scale patterns of biodiversity across space and altitudinal ranges. We found that geographic inaccuracy affects diversity patterns more than taxonomic uncertainties, often leading to false positives, i.e. overestimating species richness in relatively species poor regions. Public databases for species distribution are valuable and should be more explored, but under scrutiny and validation by taxonomic experts. We suggest that database managers implement easy ways of community feedback on data quality.

Phylogeny of the herbaceous tribe Spermacoceae (Rubiaceae) based on plastid DNA data

Abstract In its current circumscription, the herbaceous tribe Spermacoceae s.l. (Rubiaceae, Rubioideae) unites the former tribes Spermacoceae s. str., Manettieae, and the Hedyotis–Oldenlandia group. Within Spermacoceae, and particularly within the Hedyotis–Oldenlandia group, the generic delimitations are problematic. Up until now, molecular studies have focused on specific taxonomic problems within the tribe. This study is the first to address phylogenetic relationships within Spermacoceae from a tribal perspective. Sequences of three plastid markers (atpB-rbcL, rps16, and trnL-trnF) were analyzed separately as well as combined using parsimony and Bayesian approaches. Our results support the expanded tribe Spermacoceae as monophyletic. The former tribe Spermacoceae s. str. forms a monophyletic clade nested within the Hedyotis–Oldenlandia group. Several genera formerly recognized within the Hedyotis–Oldenlandia group are supported as monophyletic (Amphiasma Bremek., Arcytophyllum Willd. ex Schult. & Schult. f., Dentella J. R. Forst. & G. Forst., Kadua Cham. & Schltdl., and Phylohydrax Puff), while others appear to be paraphyletic (e.g., Agathisanthemum Klotzsch), biphyletic (Kohautia Cham. & Schltdl.), or polyphyletic (Hedyotis L. and Oldenlandia L. sensu Bremekamp). Morphological investigations of the taxa are ongoing in order to find support for the many new clades and relationships detected. This study provides a phylogenetic hypothesis with broad sampling across the major lineages of Spermacoceae that can be used to guide future species-level and generic studies.

Phylogenetic structure and clade circumscriptions in the Gardenieae complex (Rubiaceae)

In this study we investigate the large and diverse Rubiaceae-Gardenieae and closely related tribes Bertiereae, Coffeeae, Cremasporeae, Octotropideae, and Pavetteae. Some of the tribes or groups have been shown to be monophyletic and strongly supported, but the phylogeny of this large complex is still far from being satisfactorily elucidated particularly for Gardenieae, both in terms of intertribal relationships as well as tribal delimitations. We reconstruct the phylogeny of the complex using an extensive sampling of 108 genera and five plastid DNA regions. Phylogenetic relationships demonstrate that Gardenieae sensu Andreasen & Bremer is polyphyletic, as Burchellia, Didymosalpinx, Monosalpinx, and Mantalania are closer to Octotropideae-Cremasporeae. In addition, Pavetteae and the investigated members of Aulacocalyceae are nested in a supported but partially unresolved Gardenieae-Pavetteae clade. Within this clade, several strongly supported groups are resolved: an Aidia group, an Alibertia group, a Gardenia group, Pavetteae including Pelagodendron, a Porterandia group, a Randia group, a Rothmannia group (including Aulacocalyx and Heinsenia), a Sherbournia group, and the two isolated genera Massularia and Schumanniophyton. The latter genus presented a high rate of genetic substitutions, which resulted in perturbations of the phylogenetic reconstruction. A revised tribal circumscription is given for Gardenieae, the Alibertia group is recognized at tribal level as an emended Cordiereae, and a new tribe, Sherbournieae, is described to accommodate the members of the Sherbournia group.

Screening for leaf-associated endophytes in the genus Psychotria (Rubiaceae)

Burkholderia endophytes were identified within the leaves of non-nodulated members of the genus Psychotria. In contrast to leaf-nodulated Psychotria species, which are known to accommodate their endosymbionts into specialized endosymbiont-housing structures, non-nodulated species lack bacterial leaf nodules and harbor endosymbionts intercellularly between mesophyll cells. Based on molecular data (rps16, trnG, and trnLF), the phylogenetic reconstruction of the host plants revealed a separate origin of leaf-nodulated and non-nodulated Psychotria species. Despite a distinct phylogenetic position of the two host clades, the endophytes of the non-nodulated plants were not placed into a single monophyletic group but were found to be closely related to the leaf-nodulated endosymbionts. The observation of genetically similar endophytes in both nodulated and non-nodulated Psychotria lineages suggests that the host plant is playing a crucial role in the induction of leaf nodule formation. Moreover, the concentration of endosymbionts into specialized leaf nodules may be considered as a more derived evolutionary adaptation of the host plant, serving as an interface structure to facilitate metabolic exchange between plant and endosymbiont.

Rubiacearum Americanarum Magna Hama Pars XXVIII: New Taxa, New Combinations, New Names, and Lectotypification for Several Species Found in Mexico and Central America

Abstract.  The Neotropical genus Borojoa Cuatrec. (Rubiaceae) is now considered a synonym of Alibertia A. Rich. ex DC. Consequently, three species named in Borojoa and found in Costa Rica and Panama are transferred to Alibertia with these corresponding nomenclatural changes: the new combination A. atlantica (Dwyer) Delprete & C. H. Perss. is based on B. atlantica Dwyer, the new name A. dwyeri Delprete & C. H. Perss. is provided for B. panamensis Dwyer, and the new combination A. patinoi (Cuatrec.) Delprete & C. H. Perss. is provided for B. patinoi Cuatrec. Additionally, the species A. premontana C. M. Taylor is reduced to a variety of A. edulis (Rich.) A. Rich. ex DC., as A. edulis var. premontana (C. M. Taylor) Delprete & C. H. Perss. A lectotype is selected for A. edulis. The recent publication of Arachnothryx chimalaparum Lorence ex Borhidi designated a holotype deposited at MO, but no such specimen has been located; a lectotype is here chosen based on a duplicate of the holotype deposited at MEXU. The new species Notopleura recondita Hammel & C. M. Taylor of the Osa Peninsula of Costa Rica can be distinguished from N. polyphlebia (Donn. Sm.) C. M. Taylor by its leaf blades with the secondary veins plane on the adaxial surface and its short cymose or paniculiform inflorescences. The new species Palicourea matamana C. M. Taylor of premontane forests of central-eastern Costa Rica can be separated from P. orosiana C. M. Taylor by its larger stipules, longer calyx lobes, and hirsute pubescence. The new species P. providenciana J. Sánchez-Gonz. & C. M. Taylor of montane forests in south-central Costa Rica can be separated from P. hammelii C. M. Taylor by its longer lanceolate stipule lobes, dark purple or yellow-flushed inflorescences, and shorter calyx lobes. The Panamanian plants treated previously as Psychotria acuminata subsp. boraginoides Dwyer are here considered to differ at the species level from P. acuminata Benth., and accordingly the new combination P. boraginoides (Dwyer) C. M. Taylor is here published for this species. Clarification of the identity of Cephaelis croatii Dwyer shows that it is a distinct species of Psychotria, and the new combination P. croatii (Dwyer) C. M. Taylor is published here for this species. The new species P. herrerana C. M. Taylor of central Costa Rica can be recognized by its combination of large, sessile, elliptic leaves, its large paniculiform inflorescences, and its relatively small corollas. Study of the Costa Rican plants previously called Rudgea thyrsiflora Donn. Sm. shows that these do not have the characters of Rudgea, but are similar to Psychotria racemosa Rich. and better included in this latter genus; the new name P. tsakiana C. M. Taylor is here published for this species. The new combination Simira panamensis (Dwyer) C. M. Taylor is published here based on the name Bathysa panamensis Dwyer, which has priority over the name S. darienensis Dwyer; both of the names Dwyer published are based on the same type specimen, thus the later name S. darienensis is illegitimate.

Phylogeny Predicts the Quantity of Antimalarial Alkaloids within the Iconic Yellow Cinchona Bark (Rubiaceae: Cinchona calisaya)

Considerable inter- and intraspecific variation with respect to the quantity and composition of plant natural products exists. The processes that drive this variation remain largely unknown. Understanding which factors determine chemical diversity has the potential to shed light on plant defenses against herbivores and diseases and accelerate drug discovery. For centuries, Cinchona alkaloids were the primary treatment of malaria. Using Cinchona calisaya as a model, we generated genetic profiles of leaf samples from four plastid (trnL-F, matK, rps16, and ndhF) and one nuclear (ITS) DNA regions from twenty-two C. calisaya stands sampled in the Yungas region of Bolivia. Climatic and soil parameters were characterized and bark samples were analyzed for content of the four major alkaloids using HPLC-UV to explore the utility of evolutionary history (phylogeny) in determining variation within species of these compounds under natural conditions. A significant phylogenetic signal was found for the content of two out of four major Cinchona alkaloids (quinine and cinchonidine) and their total content. Climatic parameters, primarily driven by changing altitude, predicted 20.2% of the overall alkaloid variation, and geographical separation accounted for a further 9.7%. A clade of high alkaloid producing trees was identified that spanned a narrow range of altitudes, from 1,100 to 1,350 m. However, climate expressed by altitude was not a significant driver when accounting for phylogeny, suggesting that the chemical diversity is primarily driven by phylogeny. Comparisons of the relative effects of both environmental and genetic variability in determining plant chemical diversity have scarcely been performed at the genotypic level. In this study we demonstrate there is an essential need to do so if the extensive genotypic variation in plant biochemistry is to be fully understood.

Nuevos Taxones de Rubiaceae de la Costa Pacífica de Colombia y Ecuador@@@Nuevos Taxones de Rubiaceae de la Costa Pacifica de Colombia y Ecuador

The new species Coussarea sancti-ci- prianii C. M. Taylor, Duroia laevis Devia, Persson & C. M. Taylor, Duroia sancti-ciprianii Devia, Pers- son & C. M. Taylor, Faramea ampla C. M. Taylor, Faramea monsalveae C. M. Taylor, Faramea cali- mana C. M. Taylor, and Psychotria monsalveae C. M. Taylor, and the new subspecies Coussarea lof- tonii subsp. calimana C. M. Taylor are here de- scribed based on material collected for the floristic inventory of the Bajo Calima and Rio Escalerete project regions in coastal Valle del Cauca Depart- ment, Colombia; several of these species range north to Choc6 Department and south into north- western Ecuador.

First record of Chomelia triflora (J.H. Kirkbr.) Delprete & Achille (Rubiaceae) from Brazil

This paper presents the first record of Chomelia triflora from Brazil, to date a species only known from French Guiana. After examining herbaria collections and doing fieldwork in the Brazilian Amazon, we found that the species also occurs in and around the Ducke Reserve in the state of Amazonas, Brazil. Our finding increases the data about the Brazilian Amazon and contributes to the better knowledge of Chomelia in Brazil.

Sphinctanthus fluvii-dulcis (Rubiaceae: Gardenieae), a new species from the Rio Doce Valley, Atlantic forest of Minas Gerais, Brazil, with detailed observations on ovary morphology

SummaryA new species of Sphinctanthus from the Rio Doce Valley, Atlantic forest in the state of Minas Gerais, Brazil, is here described and illustrated. The species is peculiar within the genus by having placentation entirely parietal, while in the other species of Sphinctanthus the placentation is basally axial and distally parietal. In addition, despite its bright orange flowers (being a plant with high potential as an ornamental), it is only known from two collections from nearby localities, indicating that it is a rare and critically endangered species.ResumoUma nova espécie de Sphinctanthus proveniente do Vale do Rio Doce, na Floresta Atlantica do Estado de Minas Gerais, Brasil, é aqui descrita e ilustrada. A espécie é peculiar dentro do gênero por ter placentação completamente parietal, em quanto que nas outras espécies a placentação é basalmente axial e distalmente parietal. Também, apesar das flores de cor laranja vivo (sendo uma planta com alto potencial de ser cultivada como ornamental), ela é conhecida somente por duas coletas em localidades muito proximas, indicando que é uma espécie rara e criticamente em perigo.