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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
    A Revision of Neotropical Bonyunia (Loganiaceae: Antonieae)
    Grant, Jason 
    A revision of the Neotropical genus Bonyunia M. R. Schomb. ex Progel (Loganiaceae, Antonieae) is provided, including a key to species, description, distribution, IUCN Red List status, and discussion. Bonyunia is morphologically and ecologically diverse with taxonomically informative characters that include habit, seed and leaf morphology, and the shape and indument of the calyx, bracts, and bracteoles. Bonyunia occurs in lowland regions of the Amazon River watershed (Brazil and Bolivia), the Orinoco River watershed (Colombia and Venezuela), tepuis of the Guayana region and outliers (Brazil, Guyana, Venezuela, and Colombia), and lowland regions of Amazon Basin–facing Andes in Peru, throughout on white sands. Ten species are recognized, including four established species: B. antoniifolia Progel, B. aquatica Ducke, B. minor N. E. Br. (including B. cinchonoides Gleason & Standl.), and B. superba M. R. Schomb. ex Progel. Six species are newly described: B. excelsa J. R. Grant (Colombia), B. magnifica J. R. Grant (Brazil), B. nobilis J. R. Grant (Colombia), B. pulchra Ricketson, J. R. Grant & Liesner (Peru), B. spectabilis J. R. Grant (Guyana), and B. venusta J. R. Grant (Brazil).
  • 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 : IV: ELEVEN NEW SPECIES OF MACROCARPAEA (GENTIANACEAE: HELIEAE) FROM CENTRAL AND SOUTH AMERICA, AND THE FIRST REPORT OF THE PRESENCE OF STIPULES IN THE FAMILY
    Grant, Jason 
    ;
    Weaver, Richard E. Jr
    Progress toward a taxonomic revision of Macrocarpaea (Gentianaceae: Helieae) has revealed numerous novelties in this morphologically diverse and unexpectedly species-rich genus. Eleven new species are here described and illustrated from Central and South America: Colombia (M. nicotianifolia and M. schultesii), Costa Rica (M. auriculata), Ecuador (M. subsessilis), Peru (M. gracilis, M. maguirei, M. wurdackii, and M. zophoflora), and Venezuela (M. ewaniana, M. papillosa, and M. weaveri). Macrocarpaea zophoflora is notable for being the first species to be described of Gentianaceae that is known, or recognized, to have free deciduous interpetiolar stipules. The family was previously defined as exstipulate without exception.
  • 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.
  • Publication
    Accès libre
    DE MACROCARPAEAE GRISEBACH (EX GENTIANACEIS) SPECIEBUS NOVIS II: TYPIFICATION OFTHE RUIZ AND PAVON NAMES
    Grant, Jason 
    Ruiz and Pavon described four species of Lisianthus (Gentianaceae) that are now recognized in the genus Macrocarpaea : Lisianthus corymbosus, L. ovalis, L. revolutus, and L. viscosus. These species were described from specimens collected in the province of Huánuco, Peru, and are here identified as relatively narrow endemics largely of that province. Their complicated taxonomie or nomenclatural history has required a careful review that revealed interesting details relevant to their circumscriptions. Lectotypes are selected for Lisianthus corymbosus, L. revolutus, L. viscosus, Macrocarpaea arborescens, M. pachystyla, and M. sodiroana. Lisianthus corymbosus is recognized as an illegitimate name, and is therefore reduced to synonymy under the next validly published name, Macrocarpaea pachystyla. Lisianthus ovalis does not have a type, and is therefore excluded from use. Macrocarpaea arborescens is identified here as a species of southern Ecuador, previously recognized as M. ovalis. The name "Macrocarpaea magnifica Ewan, ined" is a nomen herbariorum, here recog- nized as M. arborescens. The previously broadly circumscribed Macrocarpaea sodiroana is here recognized as restricted to the province of Pichincha, Ecuador. A new identification is reported where the anomalous specimen Dannouse s.n. (NY) previously identified as " Macrocarpaea sp." by Ewan (1948) is identified as Tabernaemontana crassa (Apocynaceae).
  • Publication
    Accès libre
    DE MACROCARPAEAE GRISEBACH (EX GENTIANACEIS) SPECIEBUS NOVIS V: TWENTY-THREE NEW SPECIES LARGELY FROM PERU, AND TYPIFICATION OF ALL SPECIES IN THE GENUS
    Grant, Jason 
    In preparation for a monograph of Macrocarpaea (Gentianaceae: Helieae), 23 new species are here described and illustrated: 1 from Colombia (M. biremis), 3 from Ecuador (M. elix, M. gattaca, and M. pringleana), and 19 from Peru (M. canoëfolia, M. dillonii, M. ericii, M. fortisiana, M. innarrabilis, M. jalca, M. kayakifolia, M. kuelap, M. kuepferiana, M. luya, M. normae, M. obnubilata, M. ostentans, M. pajonalis, M. robin-fosteri, M. tabula-fluctivagifolia, M. tahuantinsuyuana, M. wallnoeferi, and M. weigendiorum). A list of all names originally described in, or transferred to, Macrocarpaea as of year 2002 is presented. Lectotypes are selected for 12 taxa as follows: Lisianthus obtusifolius var. constrictus Griseb., Macrocarpaea bangiana Gilg, M. bogotana Gilg, M. calophylla Gilg, M. chlorantha Gilg, M. cochabambensis Gilg-Ben., M. glaziovii Gilg, M. hartii Krug & Urb., M. micrantha Gilg, M. pachyphylla Gilg, M. polyantha Gilg, and M. rubra Malme. A neotype is selected for M. duquei Gilg-Ben., and M. weberbaueri Gilg is excluded from use.
  • Publication
    Accès libre
    Cytotaxonomic notes on the tribe Helieae (Gentianaceae)
    Trunz, Vincent
    ;
    Zeltner, Louis
    ;
    Küpfer, Philippe 
    ;
    Grant, Jason 
    A survey of all known chromosome counts of gentian tribe Helieae are presented including new reports for ten species. Amongst the novelties are four genera of the Gentianaceae that are reported for the first time, Calolisianthus and Helia (both Helieae), and Schultesia and Zygostigma (both Chironieae). In the Helieae, our results reinforce the hypothesis of Weaver 1969 that two ploidy series occur in the tribe, one polyploid based on n = 20 and one dysploid based on n = 21. The basal chromosome number for the Helieae remains to be determined.
  • Publication
    Accès libre
    YANOMAMUA ARACA (GENTIANACEAE), A NEW GENUS AND SPECIES FROM SERRA DO ARAÇÁ, AN OUTLIER OF THE GUAYANA REGION IN AMAZONAS STATE, BRAZIL
    Grant, Jason 
    ;
    Maas, Paul J. M
    ;
    Struwe, Lena
    Yanomamua araca is described as a new genus and species from Serra do Araçá, an outlier of the Guayana Region in the state of Amazonas, Brazil. Yanomamua is unique in the Gentianaceae as an herb with sessile subcordate pandurate (fiddle-shaped) leaves, and inflorescences composed of oppositely paired solitary flowers situated in the axils of the upper three leaf pairs. Only limited material is available, and flower morphology is unknown. A phylogenetic approach was used to investigate possible relationships to other genera in Helieae, which yielded a likely relationship to several genera in the Symbolanthus-Chelonanthus clade but not a strong relationship to any particular genus. Instead it appears that this genus might represent a more internal, older branch within the tribe.