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Grant, Jason

Nom
Grant, Jason
Affiliation principale
Fonction
Professeur.e ordinaire
Email
jason.grant@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/30709
_
0000-0002-1197-1131

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  • Publication
    Accès libre
    Andean Speciation and Vicariance in Neotropical Macrocarpaea (Gentianaceae-Helieae)
    Struwe, Lena
    ;
    Haag, Scott
    ;
    Heiberg, Einar
    ;
    Grant, Jason 
    The genus Macrocarpaea (Griseb.) Gilg (Gentianaceae, Helieae) is among the largest woody genera of tropical gentians, with most of its species occurring in the wet mountainous forests of the Andes. Phylogenetic and dispersal-vicariance analyses (DIVA) of 57 of the 105 currently recognized species in the genus, using two data sets from nuclear DNA (ITS and 5S-NTS sequences) and morphology, show a single origin of the Andean species from an ancestral distribution that includes southeastern Brazil. Within the Andes, species divide into two major clades: (1) northern species from the cordilleras of northern Ecuador, Colombia, and Venezuela; and (2) southern species of the Andean Amotape–Huancabamba Zone in Ecuador and Peru, as well as the Andes of central and southern Peru and Bolivia. The Amotape–Huancabamba Zone is supported as the ancestral area for Macrocarpaea within the Andes. There are repeated speciation patterns within the Andes, and three Mesoamerican species derive from the northern clade, as is the single sampled species from the Guayana Shield. The position of the subclade of the three Caribbean species is less certain, but it currently nests among Andean species. An Atlantic coastal Brazilian clade is placed as sister group to all other Macrocarpaea, providing further support for an ancestral refuge in southeastern Brazil for the Helieae. The biogeographic analysis showed that local speciation is more common than long-distance dispersal, and allopatric speciation is more common than sympatric speciation. Using detailed, georeferenced herbarium collection data, patterns in environmental characteristics between clades and sister species were analyzed with Spatial Evolutionary and Ecological Vicariance Analysis (SEEVA), utilizing geographic information system (GIS) and statistical methods. Sister clades and taxa were evaluated for statistical significance in variables such as annual rainfall and temperature, elevation, temperature and rainfall seasonality, geological bedrock age, and soil type to evaluate ecological vicariance between sister groups. The results indicate that there are no general patterns for each variable, but that there are many significant divergences in ecological niches between both larger sister groups and sister species, and ecological niche conservation was also observed when subsequent nodes in the phylogeny were compared.
  • Publication
    Accès libre
    DE MACROCARPAEAE GRISEBACH (EX GENTIANACEIS) SPECIEBUS NOVIS III: SIX NEW SPECIES OF MOON-GENTIANS (MACROCARPAEA, GENTIANACEAE: HELIEAE) FROM PARQUE NACIONAL PODOCARPUS, ECUADOR
    Grant, Jason 
    ;
    Struwe, Lena
    In preparation for the Flora Neotropica monograph of Macrocarpaea (Gentianaceae: Helieae) and recent fieldwork in Ecuador, six new species have been identified and are here described from Parque Nacional Podocarpus and its surrounding areas in Loja and Zamora-Chinchipe provinces. These are Macrocarpaea apparata, M. bubops, M. jensii, M. lenae, M. luna-gentiana, and M. noctiluca. For each new species, descriptions, illustrations, and ecological information are provided. The neotropical montane genus Macrocarpaea has among the highest biodiversity in Ecuador with over 30 species present. The name “moon-gentian” or “genciana de luna” is coined as the common name for the genus Macrocarpaea.
  • Publication
    Accès libre
    DE MACROCARPAEAE GRISEBACH (EX GENTIANACEIS) SPECIEBUS NOVIS I: AN INTRODUCTION TO THE GENUS MACROCARPAEA AND THREE NEW SPECIES FROM COLOMBIA, ECUADOR, AND GUYANA
    Grant, Jason 
    ;
    Struwe, Lena
    A monographic revision of the neotropical genus Macrocarpaea (Gentianaceae: Helieae) has been initiated. The taxonomic and nomenclatural background is provided as an introduction in this first of several papers. These gentians are typically montane shrubs with large, funnelform, night-blooming, bat-pollinated flowers and have a high rate of species endemicity. It is also an excellent group from which to study neotropical montane biogeography, since they occur in all major neotropical montane habitats. Three new species are described and illustrated: Macrocarpaea angelliae (Ecuador) in discussion with M. stenophylla where a neotype is selected, M. ayangannae (Guyana), and M. luteynii (Colombia). New synonymy is reported for one published species [Macrocarpaea guttifera = Ravenia biramosa (Rutaceae)] and six “nomen herbariorum”: “Axelsonia globiflora Dusén, ined.” = M. rubra, “M. buchtienii Gilg, ined.” = M. cinchoniifolia, “M. ekmanii Ewan, ined.” = M. pinetorum, “M. gilgiana Rusby, ined.” = M. cochabambensis, “M. peduncularis Rusby, ined.” = M. bangiana, and “M. tabacifolia Ewan, ined.” = M. cinchoniifolia.