Diversity and distribution of lichens from the Cerro Duida and adjacent areas, Alto Orinoco, Amazonas, Venezuela

Increasing temperature and changing land-use in the Guayana Shield and Amazonia result in an accelerated decline of sensitive lichen populations. Monitoring of these populations by biological plot inventories in particularly vulnerable sites is urgently needed. In order to know the diversity and distribution of lichen species at the Alto Orinoco, Parque Nacional Duida-Marahuaca and nearby areas from Amazonas state, Venezuela, lichens were sampled during four expeditions in more than 40 plots located from 200 m (premontane forest) to more than 1500 m elevation (altotepuyana vegetation). Additional data were obtained from literature and herbaria. Our assessment, although incomplete, revealed 205 described species, 150 undescribed species, 84 genera and 27 families. Among the described species 162 were observed in the basimontane vegetation, 38 in the montane vegetation, 24 in the altotepuyana vegetation, while 20 appear to be endemic to the study area. Sixty-nine species are new records for the Cerro Duida. A checklist with taxonomic and ecological data is presented. Five new species and one new variety are described: Cladonia duidana V.Marcano & A.Morales sp. nov. (Cladoniaceae), Pertusaria orinoquensis V.Marcano sp. nov., Sticta kunuhana V.Marcano sp. nov. (Lobariaceae), S. spruceana V.Marcano sp. nov. (Lobariaceae), Xanthoparmelia esmeraldensis V.Marcano & A.Morales sp. nov. (Parmeliaceae), and Lepraria arbuscula (Nyl.) Lendemer & Hodk. var. fumarprotocetrarica V.Marcano var. nov.

Sertulum Ternstroemiacearum I. Sinopsis del género Freziera (Ternstroemiaceae) en Venezuela, incluyendo una especie nueva de la Cordillera de Mérida

The genus Freziera Willd. is distributed in Venezuela along major mountain systems, including Los Andes, Coastal Cordillera, and Guayana Shield. Two out of 11 Freziera species known from Venezuela are endemic to this country and could be endangered, but their actual conservation status is unknown, being Data Deficient according to the criteria of the IUCN. In this work, a key for the Venezuelan species is provided for the first time, and Freziera polita A.L.Weitzman ex J.R. Grande, sp. nov., from Cordillera de Mérida, is described and illustrated. Diagnostic characters of the new species, which is most closely similar to F. Guaramacalana D.Santam. & Cuello, include elongated petioles, subglabrous mature leaves, and corollas (at anthesis) that are exerted less than half the length of sepals.

Botanical novelties from the Sierra de Maigualida, southern Venezuela III: revision and two new species of the genus Ilex (Aquifoliaceae)

The Sierra de Maigualida is a poorly explored mountain range in the central Guayana Shield with high levels of endemism. In the present installment, this area is further delimited and mapped, toponymy is reviewed, and the genus Ilex L. is locally reviewed, with two species, namely I. huberi J.R.Grande sp. nov. and I. maigualidensis J.R.Grande sp. nov., described as new to science. Ilex huberi sp. nov. can be distinguished by its leaf blades strongly revolute, mucronate, and with obscure secondary venation, simple dichasia, and depressed-lunate sepals; I. maigualidensis sp. nov. by its dull leaves, flowers with undeveloped styles, and capitate-subcoronate stigmata. Stem buds and cataphylls are proposed as useful characters in species delimitation within the genus, while I. magnifructa Edwin is illustrated for the first time. A key is presented to differentiate all the species of Ilex of the Sierra de Maigualida.

Convolvulaceae neotropicae novae vel minus cognitae III: Jacquemontia austiniana J.R.Grande sp. nov. (Convolvulaceae), a new species from the Venezuelan Guayana

As a part of a taxonomic update of the family Convolvulaceae Juss. for Guayana Shield, the species Jacquemontia austiniana J.R.Grande sp. nov., is described and illustrated as new to science. This species is characterized by its linear-subulate bract, ovate-lanceolate external sepals, conspicuously acuminate, villose, with the margins ciliate, and a relatively large and infundibuliform corolla. To date, this is the only species of Jacquemontia Choisy endemic to the Guayana Shield; its relationships within the genus are still to be elucidated.

Moutabea chartacea (Polygalaceae), a new species from the north-central Amazon and Guayana Shield

Se describe e ilustra la especie Moutabea chartacea, de los bosques húmedos de tierras bajas de Brasil (estado Amazonas), Venezuela (estados Amazonas, Bolívar y Delta Amacuro) y Colombia (departamentos de Caquetá, Meta y Vaupés), y se discuten sus relaciones morfológicas con su especie afín. Esta nueva especie es similar a M. gentryi, sin embargo, difiere por poseer los pecíolos, hojas, lóbulos de cáliz, frutos y semillas más pequeños, así como brácteas triangulares, pétalos con los ápices no reflexos y semillas densamente cubiertas por tricomas estrellados. Se incluye una clave actualizada de las especies de Moutabea. © 2018. Acad. Colomb. Cienc. Ex. Fis. Nat.

Up on the table mountains in Brazil: new Bromeliaceae and Eriocaulaceae (Poales) from the Pantepui in the Guayana Shield

Background and aims – As “islands in the sky” of northern South America, the isolated ecosystems of the Pantepui province include a distinct flora with high levels of endemism and which are ancestral areas for many angiosperm lineages. About one fifth of Pantepui angiosperm species are distributed in Poales, a highly diverse angiosperm order.Methods – Recent field trips were carried out on two Brazilian tepuis, by foot and helicopter. Herbarium collections were consulted and compared with the proposed new species. Key results – Four new species of Poales, three Navia Schult. & Schult.f. (Bromeliaceae) and one Paepalanthus Mart. (Eriocaulaceae) were found. Descriptions, illustrations, and distribution maps of the new species, as well as an identification key to Brazilian Navia species, are provided.

Sertulum Ternstroemiacearum II: Ternstroemia tepuiensis J.R.Grande, sp. nov. (Ternstroemiaceae),especie nueva del Escudo Guayanés

As a part of an ongoing review for the genus Ternstroemia in the Guayana Shield, in northern South America, T. tepuiensis J.R.Grande, sp. nov. is described as new to science. This species, characterized by its relatively large leaves, flowers and fruits, as well as by its circumscissile dehiscent fruits, is only known from the sandstone tabletop mountains commonly named as «tepuis», where it seems to be a rather common floristic element. Ecological and biogeographical notes are included, while the conservation status of the new species is assessed as LC —Least Concern, following the IUCN Red List Categories—. A key to separate this species from remaining members of the genus that bear fruits with circumscissile dehiscence is offered at the end of the paper.

Three new species of the Cyathea “Hymenophyllopsis” clade (Cyatheaceae) from Venezuela and Brazil

Three new species of Cyathea, two from Venezuela and one from Venezuela and the border region between Venezuela and Brazil, are here described: Cyathea alsophiloides, C. cylindrica, and C. lellingeriana. These species are endemic to the tepuis of the Guayana Shield and occur mainly at high elevations (1850–2555 m, although C. lellingeriana also grows down to 770 m). Descriptions, illustrations and mapped distributions are provided for each species, and their similarities to and differences from other species of the Hymenophyllopsis clade in Cyathea are discussed.

Manipulus Guttiferarum, II. First record of Clusia ucamira (Clusiaceae) from Venezuelan Guayana

As part of a review in progress on the genus Clusia Linnaeus in Venezuela, Clusia ucamira J.E. Nascim. & Bittrich is reported for the first time for that country. Clusia ucamira is quickly distinguished from similar species of Clusia sect. Oedematopus (Planchon & Triana) Pipoly by its hemiepiphitic habit, strongly coriaceous and conspicuously revolute leaves, with a very prominent midvein in the abaxial surface. With this range extension, Clusia ucamira is known, besides from the Amazon basin, from terra firme forest in the Amazonas state of Venezuela, where it grows in oligotrophic soils derived from materials from the Guayana Shield. In Venezuela, this species is to be considered Least Concerned (LC), according to the IUCN Red List categories.