Etudes sur la flore des Guyanes / 22 : deux Passifloraceae nouvelles et quelques espèces rares en Guyane française

Description de #Passiflora rufostipulata et #P. fanchonae, espèces nouvelles de Guyane française ; premières récoltes en Guyane de #P. acuminata et #P. variolata ; récoltes de l'espèce mal connue #P. citrifolia$. (Résumé d'auteur

Two new combinations in Euploca Nutt. (Heliotropiaceae, Boraginales) and a conspectus of the species of the Guiana Shield area

Heliotropium foliatum and Tournefortia humilis are transferred to Euploca Nutt. respectively as Euploca foliata comb. n. and Euploca humilis comb. n. A collection from Guyana has been recently identified as Euploca humistrata, a species previously considered a Brazilian endemic. A collection from French Guiana documents for the first time the species in that country. A key to the species of the Guiana Shield area is given. The species of Euploca from the Guiana Shield are listed with synonymy and a brief description: E. filiformis, E. humilis, E. humistrata, E. lagoensis, E. polyphylla, E. procumbens.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Pensoft Publishers. The published article can be found at: http://www.pensoft.net/journals/phytokeysKeywords: Boraginales, Heliotropiaceae, Brazil, Guianas, Guiana Shield, Venezuela, EuplocaKeywords: Boraginales, Heliotropiaceae, Brazil, Guianas, Guiana Shield, Venezuela, Euploc

La banque de données "AUBLET" de l'Herbier du centre ORSTOM de Cayenne (CAY)

L'herbier du Centre ORSTOM de Cayenne (CAY) est entièrement informatisé. Il comprend 50 000 spécimens répartis en 4 300 espèces. Les informations ont été stockées dans une banque de données appelée "AUBLET". Celle-ci peut être interrogée sur la taxonomie, les échantillons, les collecteurs, les localités de collecte ainsi que la localisation des parts dans les différents herbiers. (Résumé d'auteur

Liste des espèces de Phanérogames et de Ptéridophytes de Guyane française d'après l'Herbier du Centre ORSTOM de Cayenne

La liste présente les noms de 3.748 espèces et des 337 taxons infraspécifiques des plantes récoltées en Guyane française et dont au moins un échantillon a été déposé à l'Herbier du Centre ORSTOM de Cayenne depuis sa création en 1956. (Résumé d'auteur

The HR 1614 moving group is not a dissolving cluster

The HR 1614 overdensity in velocity space and has for a long time been known as an old (~2 Gyr) and metal-rich ([Fe/H]~0.2) nearby moving group that has a dissolving cluster origin. The existence of such old and metal-rich groups in the solar vicinity is quite unexpected since the vast majority of nearby moving groups are known to be young. In the light of new and significantly larger data sets we aim to re-investigate the properties and origin of the HR 1614 moving group. To identify and characterise the HR 1614 moving group we use astrometric data from Gaia DR2; distances, extinction, and reddening corrections from the StarHorse code; elemental abundances from the GALAH and APOGEE spectroscopic surveys; and photometric metallicities from the SkyMapper survey. Bayesian ages were estimated for the SkyMapper stars. Since the Hercules stream is the closest kinematical structure to the HR 1614 moving group in velocity space, we use it for comparison purposes. Stars that are likely to be members of the two groups were selected based on their space velocities. The HR 1614 moving group is located mainly at negative U velocities, does not form an arch of constant energy in the U-V space and is tilted in V. The overdensity is not chemically homogeneous but that its stars exist at a wide range of both metallicities, ages, and elemental abundance ratios. They are essentially similar to what is observed in the Galactic thin and thick disks, a younger population (~3 Gyr) that is metal-rich (-0.2<[Fe/H]<0.4) and alpha-poor. It should therefore not be considered as a dissolving open cluster, or an accreted population. We suggest that HR 1614 has a complex origin that could be explained by combining several different mechanisms such as resonances with the Galactic bar and spiral structure, phase-mixing of dissolving spiral structure, and phase-mixing due to an external perturbation.Comment: Accepted for publication in A&

Comparative analysis of atmospheric parameters from high-resolution spectroscopic sky surveys: APOGEE, GALAH, Gaia-ESO

SDSS-IV APOGEE-2, GALAH and Gaia-ESO are high resolution, ground-based, multi-object spectroscopic surveys providing fundamental stellar atmospheric parameters and multiple elemental abundance ratios for hundreds of thousands of stars of the Milky Way. We undertake a comparison between the most recent data releases of these surveys to investigate the accuracy and precision of derived parameters by placing the abundances on an absolute scale. We discuss the correlations in parameter and abundance differences as a function of main parameters. Uncovering the variants provides a basis to on-going efforts of future sky surveys. Quality samples from the APOGEE-GALAH, APOGEE-GES and GALAH-GES overlapping catalogs are collected. We investigate the mean variants between the surveys, and linear trends are also investigated. We compare the slope of correlations and mean differences with the reported uncertainties. The average and scatter of vrad, Teff, log g, [M/H] and vmicro, along with numerous species of elemental abundances in the combined catalogs show that in general there is a good agreement between the surveys. We find large radial velocity scatters ranging from 1.3 km/s to 4.4 km/s when comparing the three surveys. We observe weak trends: e.g. in $\Delta$Teff vs. $\Delta$log g for the APOGEE-GES stars, and a clear correlation in the vmicro-$\Delta$vmicro planes in the APOGEE-GALAH common sample. For [$\alpha$/H], [Ti/H] (APOGEE-GALAH giants) and [Al/H] (APOGEE-GALAH dwarfs) potential strong correlations are discovered as a function of the differences in the main atmospheric parameters, and we find weak trends for other elements. In general we find good agreement between the three surveys within their respective uncertainties. However, there are certain regimes in which strong variants exist, which we discuss. There are still offsets larger than 0.1 dex in the absolute abundance scales.Comment: Accepted in A&A, 23 pages, 13 figures, 6 tables. A minor correction is applied to the Gaia-ESO Survey's solar reference: Grevesse et al. (2007) instead of Grevesse & Sauval (1998