Guillaume Léotard

French National Centre for Scientific Research | CNRS

Durant la période 2018-2020, dans le cadre de l’Atlas de la biodiversité communale de Saül, et grâce à des missions organisées par le Parc amazonien de Guyane, mais également dans une démarche d’inventaire permanent, un certain nombre d’observations intéressantes ont été réalisées concernant la flore vasculaire dans la zone cœur de parc, mais aussi...

Because different tropical forest regions possess their own species diversity and communities, it is crucial to investigate the diversification history of their biota to understand how biodiversity was assembled. However, this requires reliable species concepts and robust, well‐sampled phylogenies. Here we focus on the fully mycoheterotrophic genus...

TAXREF is the taxonomic register for all living organisms from metropolitain and overseas France, marine as well as continental. A new version is published each year. This 15th version can be downloaded here : https://inpn.mnhn.fr/telechargement/referentielEspece/taxref/15.0/menu

A broad range of climatic and biogeographical conditions are represented in the French Overseas Territories, from sub-polar to equatorial, resulting in a high diversity of endemic species. We mobilized data from herbaria, floras, checklists, literature, the expertise of botanists and plant ecologists to compile the most complete dataset on endemic...

Despite the long-standing cultural importance and botanical interest in Vanilla, many taxa belonging to the genus remain poorly understood. Vanilla species generally have broad geographical and ecological distributions. Most species are found in multiple countries, while local endemics are rare. Many names proposed in the eighteen and nineteenth ce...

TAXREF is the taxonomic register for all living organisms from metropolitain and overseas France, marine as well as continental. A new version is published each year. This 12th version can be downloaded here : https://inpn.mnhn.fr/telechargement/referentielEspece/taxref/12.0/menu

Habenaria paxamorque, a new graminiform-leaved species, is described from coastal savannas of French Guiana. Herbarium specimens also attest its presence in Northern Brazil (Marajó island, Pará) and Southern Suriname (Sipaliwini). It differs from other similar species most prominently by its reduced anterior petal lobes, short spur, and subequal li...

We tested the role of interspecific competition in driving species distribution at multiple spatial scales using two sibling species of Galerida larks (G. cristata and G. theklae) in Morocco (sympatry), Balearic islands (G. theklae only) and Israel (G. cristata only). We first investigated regional-scale determinants by contrasting allopatric versu...

Molecular genetic studies of the origin of cassava (M. esculenta subsp. esculenta) have concluded that domestication occurred once, from populations of M. esculenta subsp. flabellifolia along the southern rim of Amazonia. However, sampling lacked populations of the wild taxon from northern Amazonia, and the hypothesis of a second, northern domestic...

Tree investment in the feeding of ants. Mean (±standard deviation) values across trees per population of number of (1) observed nectaries per leaf and of (2) produced nectaries per basal leaflet. Populations are arranged in descending order according to their geographical distance from the southernmost known limit of the range of the system (these...

Temporal dynamics of occupation of nest sites by ants. Maximum-likelihood estimates [and 95% confidence interval] of annual survival probabilities of host-plant occupancy for Petalomyrmex phylax and Cataulacus mckeyi in six populations ordered from north to south (computed using Mark software). Only the probabilities of continued occupancy of a tre...

Geographic variation in P. phylax queen size and potential founding capacity. Within population average (mean±standard deviation) of size and survival of alate female sexuals of Petalomyrmex phylax from 21 populations: head length (HL), head width (HW), partial forewing length (PWL), forewing width (WW), total forewing length (TWL) (mm), dry weight...

The study populations: location and measures of genetic diversity. Statistics summarizing within-population genetic variation over 9 microsatellite loci for 19 populations of Leonardoxa a. africana, 12 loci for 21 populations of Petalomyrmex phylax, and 10 loci for 14 populations of Cataulacus mckeyi. Distance is the map distance (in km) from the s...

Size at which half the trees had reached sexual maturity. Estimated values [and 95% confidence interval] across trees per population and over all individuals of basal trunk diameter and tree height at which the probability of flowering is 0.50 based on logistic regressions. Populations are arranged in descending order according to their geographica...

Alate female Petalomyrmex are larger in the south. Comparison of estimated dry weight (mg) of adult individuals between the two geographically extreme populations (EBO in the south, BOU in the north) according to caste; descriptive statistics and results of ANOVAs. ns: not significant, *: P<0.05, **: P<0.01, ***: P<0.001). (0.04 MB RTF)

Recurrent climatic oscillations have produced dramatic changes in species distributions. This process has been proposed to be a major evolutionary force, shaping many life history traits of species, and to govern global patterns of biodiversity at different scales. During range expansions selection may favor the evolution of higher dispersal, and s...

Although biotic interactions are particularly intricate in the tropics, few studies have examined whether divergent adaptations to biotic interactions lead to speciation in tropical organisms. Ant-plant mutualisms are widespread in the tropics. Within Leonardoxa africana, two subspecies present contrasting defences against herbivores. Young leaves...

The ant Petalomyrmex phylax is a protective mutualistic ant associated with Leonardoxa a. africana, a small tree of coastal rainforests of Cameroon. The association has expanded southwards during the last few centuries. Northern colonies of the ant are secondarily polygynous while in southern populations, colonies are strictly monogynous. This...

Cette étude envisage la révision systématique des Dauphinelles du groupe de Delphinium pictum. On considère habituellement que ce groupe, endémique du bassin méditerranéen occidental, est constitué de deux espèces menacées, D. pictum et D. requienii, bénéficiant d’une protection et de mesures de gestion. L’analyse de la littérature révèle pourtant...