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Fil: Zuloaga, Fernando Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina

Abstract Breeding system, sexual system, temporal variation in sex expression and herkogamy were evaluated in seven herbaceous-shrubby communities from the Gran Sabana Plateau, Venezuela. This analysis was conducted considering the life form, substrate type, succulence, carbon metabolism, nutritional relation, successional stage, pollination system specificity and endemism of plant species. Of the 348 plant species studied, 73.8 % were hermaphrodite, 16.9 % were monoecious and 9.2 % were dioecious. Plant sexual systems such as dichogamy and herkogamy were associated with life form, nutritional relations, carbon metabolism and pollination systems. Most species were adichogamous, followed by protandrous and protogynous. Protandry was high for perennial herbs, annual herbs and trees, and protogyny was most frequent in perennial herbs. Protandrous and protogynous species were frequently anemophilous. Herkogamy was higher than non-herkogamy. Herkogamy was higher for trees, shrubs and liana; higher in monophilous and lower in anemophilous species. Most of the hermaphrodites were herkogamous and adichogamous species. In contrast, monoecy were commonly perennial herb and dichogamous species and frequently associated with anemophily. Dioecious species were trees and shrubs and with polyphilous pollination. Dioecy was the most frequent sexual system for endemic species. Hermaphrodite species were similarly distributed across plant communities. Monoecy was slightly higher for savanna and fallow than the other communities, and dioecy was higher for shrublands and secondary bushland. Most plant species were non-agamospermous, non-spontaneous self-pollinated and xenogamous. Partially self-incompatible dominated, followed by self-incompatible, partially cross-incompatible and the lowest frequency corresponded to cross-incompatible species. All these results are discussed in the context of evolutionary and ecological trends. Breeding system, sexual system, dichogamy and herkogamy taking place in seven herbaceous-shrubby communities from the Gran Sabana Plateau, Venezuela, showed diverse mating strategies associated with life forms, pollination system specificity, successional stage, endemism, vegetation structure and community isolation. High levels of outbreeding strategies such as dioecy, monoecy, non-agamospermy, non-spontaneous self-pollination, xenogamy and partial self-incompatibility occurred mainly in woody species from shrublands and secondary bushland. Inbreeding strategies, non-herkogamy, spontaneous self-pollination and partial cross-incompatibility are primarily associated with herbaceous life forms from disturbed communities. These reproductive attributes are discussed in the ecological and evolutionary context.

Este 2021 el Herbario Nacional de Venezuela arribó a su primer siglo de creación; este trabajo rinde homenaje a esta institución resaltando su importancia como patrimonio científico e histórico de Venezuela, de Latinoamérica y del mundo. VEN constituye la representación de la diversidad florística del país, y dada la calidad, cantidad e información de los especímenes que resguarda se mantiene entre los principales herbarios de Sur América. A lo largo de estos cien años tuvo que sor tear eventos y vicisitudes en su consolidación y funcionamiento, manteniendo una trayectoria de dicada a preservar, enriquecer y dar a conocer la diversidad de plantas y grupos afines presentes en el territorio nacional. Estos cien años son motivo de orgullo y gran satisfacción para quienes laboramos en él, preocupados en conservar y custodiar la colección que alberga, y que lo mantienen como principal herbario del país y referencia en Latinoamérica. In 2021 the National Herbarium of Venezuela reached its first century of creation; this work pays tribute to this institution highlighting its importance as scientific and historical heritage of Venezuela, Latin America and the world. VEN constitutes the representation of the floristic diversity of the country, and given the quality, quantity and information of the specimens it keeps, it is among the main herbaria of South America. Throughout these one hundred years it has had to overcome events and vicissitudes in its consolidation and operation, maintaining a trajectory dedicated to preserve, enrich and make known the diversity of plants and related groups present in the national territory. These one hundred years are a source of pride and great satisfaction for those who work in it, concerned about preserving and guarding the collection it houses, and that keep it as the main herbarium of the coun try and a reference in Latin America.

Fil: Zuloaga, Fernando Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina

Zoraida Luces de Febres representa el esfuerzo y la dedicación de mujeres por las ciencias en el país, específicamente con el estudio de las plantas, al ser la primera mujer en obtener el título de licenciada en Ciencias Naturales. Fue discípula del sabio naturalista Henri Pittier, botánico de origen suizo, a quien se le debe la fundación del Herbario Nacional de Venezuela, primera institución del país con la misión de custodiar y resguardar el acervo botánico de la nación. Zoraida Luces de Febres formó parte de la primera promoción de botánicos de Venezuela, siendo la primera agrostóloga del país. La presente contribución representa un homenaje a la Dra. Zoraida Luces de Febres, en el año de su partida, por su destacada labor en el conocimiento de la diversidad vegetal del país. Zoraida Luces de Febres represents the effort and the dedication of women for the sciences in the country, especially with the plants' study, being the first woman with the degree in Natural Sciences. She was disciple of the wise naturalist Henri Pittier, botanist of Switzerland, to who fund the National Herbarium of Venezuela, first institution of the country with the mission to take care of and to protect the botanic wealth of the nation. Zoraida Luces de Febres formed part of the first botanist graduated of Venezuela, being the foremost grass specialist of the country. The present contribution represents a tribute to Dr. Zoraida Luces de Febres, in the year of her death, for her distinguished work in the knowledge of the plants diversity of the country.

Como contribución al conocimiento florístico de la Guayana venezolana se exploraron tres sectores de la cuenca del río Cucurital (370, 421 y 1040-1460 m snm). Se recolectaron 2600 muestras botánicas agrupadas en 18 familias de pteridófitos, 113 de angiospermas y una gimnosperma, para un total de 132 familias y 1049 especies, 5 subespecies y 23 variedades. Se preparó una lista anotada de taxa. En pteridófitos predominan Hymenophyllaceae y Polypodiaceae (11 especies cada una) y Dennstaedtiaceae (10). En las angiospermas destacan Melastomataceae (87 especies), Fabaceae 𝑠.𝑙. (77), Orchidaceae y Rubiaceae (59) y Poaceae (39). Votomita roraimensis se reportó por primera vez para Venezuela. El 23,39% de las especies está restringido al Escudo Guayanés, 20,91% crece en la región guayano-amazónica, 40,78% tiene amplia distribución neotropical. 31 especies son endémicas de Venezuela, 18 se conocen solo del SE del estado Bolívar. En los bosques las especies leñosas determinan mayores afinidades florísticas de la región Guayano-amazónica con los Andes, y los elementos guayaneses incrementan con la altitud. As a contribution to the floristic knowledge of the Venezuelan Guayana and the Canaima National Park, three sectors (370, 421 and 1040-1460 m asl) in the Cucurital River Basin were explored. 2600 samples were collected grouped in 18 families of Pteridophytes, 113 Angiosperms and 1 Gymnosperm, 132 families and 1049 species, 5 subspecies and 23 varieties. An annotated list of taxa was prepared. Hymenophyllaceae and Polypodiaceae (11 species each), followed by Dennstaedtiaceae (10), predominate among Pteridophytes. The most representative angiosperm families are Melastomataceae (87 especies), Fabaceae 𝑠.𝑙. (77), Orchidaceae and Rubiaceae (59) and Poaceae (39). Votomita roraimensis was first reported for Venezuela. 23.39% of the species is restricted to the Guiana Shield, 20.91% grows in the Guayano-Amazonian region, 40.78% has a wide Neotropical distribution. 31 species are endemic to Venezuela, 18 are known only from the SE of the Bolívar State. In forests, woody species determine greater floristic affinities of the Guayano-Amazon region with the Andes, and the Guyanese elements increase with altitude.