Kelen Pureza Soares

Palmeiras (Arecaceae) no Rio Grande do Sul, Brasil

This paper is a survey of Arecaceae family in Rio Grande do Sul state. We recognize 15 native species in this state (Bactris setosa, Butia catarinensis, B. eriospatha, B. exilata, B. lallemantii, B. odorata, B. paraguayensis, B. witeckii, B. yatay, Euterpe edulis, Geonoma gamiova, G. schottiana, Syagrus romanzoffiana, Trithrinax acanthocoma and T. brasiliensis). Three species were excluded from Rio Grande do Sul flora (Acrocomia aculeata, A. totai and Butia microspadix), three names were considered synonyms (Butia missionera, B. pulposa and B. quaraimana); Butia stolonifera was considered a doubtful specie. Two natural hybrids are recognized, one of them being described in this work (x Butyagrus alegretensis and × Butyagrus nabonnandii).

Uma nova espécie de Butia (Becc.) Becc. (Arecaceae) para o Rio Grande do Sul, Brasil

A new Butia (becc.) Becc. (Arecaceae): Butia witeckii K. Soares & S. longhi, native of the central region of Rio Grande do Sul – Brazil is described and illustrated. Species related to Butia yatay (Mart.) Becc. and Butia paraguayensis (Barb. Rodr.) L.H.Bailey, differing from these two species by size and weight of the fruit (3,6-5,6x3,0-4,1 cm with 23,61-43,05 grams); size, weight and shape of epicarp/pyrene (2,8-3,5x1,6-2,3 cm with 3,43-10,11 grams, provided of thee longitudinal corners and almost always pyramidal shape on the germination pore), and by the number of pinnae (leaflets) on each side of rachis (43-61 pinnae). Differs from the latter species also by the length of the expanded portion of the peduncular bract (50-85 cm), by the legth of the inflorescence rachis (49-63 cm) and by the size (3,0-6,1 meters).

DUAS NOVAS ESPÉCIES DE Syagrus Mart. (ARECACEAE) PARA O BRASIL

Duas novas especies de Syagrus Mart. (Arecaceae) do Brasil sao descritas e ilustradas neste artigo: a primeira, Syagrus pompeoi K. Soares & R. Pimenta, especie proxima de Syagrus procumbens Noblick & Lorenzi, da qual difere pela capacidade de perfilhar, pelo maior comprimento da raque das folhas (33-50 cm), contendo maior numero de pinas de cada lado (8-15), pinas de consistencia quase membranosa, com muitas nervuras transversais visiveis e pelo maior comprimento do pedunculo da inflorescencia (10-18 cm). A segunda, Syagrus santosii K. Soares & C. A. Guim., especie proxima de Syagrus schyzophylla (Mart.) Becc., da qual difere por possuir frutos maiores (2,9-4,6 x 2,6-3,8 cm), com o epicarpo e o mesocarpo geralmente fendidos no apice quando maduros, pelo maior endocarpo (2,7-4,2 x 2,4-3 cm), com endosperma homogeneo, pela maior quantidade de pinas de cada lado da folha e por possuir maiores flores pistiladas.

The genus Tocantinia (Amaryllidaceae, Amaryllidoideae) and two new species from Brazil

A synopsis of the genus Tocantinia is provided, with two new species being described and illustrated: T. dutilhiana and T. stigmovittata . Descriptions, illustrations and data on etymology, ecology, conservation status, distribution and habitat of the species are provided. The taxonomic placement of the genus in morphological and phylogenetic aspects is discussed.

Dyckia pontesii (Bromeliaceae, Pitcairnioideae), uma nova espécie do Rio Grande do Sul, Brasil

Dyckia pontesii, a new species of Bromeliaceae (Pitcairnioideae) to Rio Grande do Sul (Brazil) is described and illustrated. Data on habitat, ecology, geographical distribution, morphological affinities and evaluation about its threat of extinction according to the criteria of the IUCN are provided.

GRAZING CHANGES THE SOIL-PLANT RELATIONSHIP IN THE TREE-REGENERATION STRATUM IN THE PAMPA OF SOUHTERN BRAZIL

Despite being prominent in flora, the region of the Parque Estadual do Espinilho located in the Pampas of southern Brazil, where dense herbaceous stratum and isolated trees make this region suitable for livestock farming, has received little attention. The objective of the study was to analyze floristic and edaphic changes imposed by livestock farming in two areas of the park, the first under livestock grazing and the second protected from grazing (livestock-excluded) for five years. We evaluated soil physical properties of and the herbaceous aboveground biomass in order to investigate relationships with key regenerating tree species. A sampling unit of 2ha was installed in both areas, each composed of 200 subunits. Inventory of regenerating trees and herbaceous aboveground biomass, soil sampling, and soil penetration resistance tests were done in 50 subunits. The results, which were evaluated by Student’s t-test, exhibited variations between the two areas in regards to floristic and environmental factors. The abundance of the P. affinis and V. caven species and the variables of soil penetration resistance, soil bulk density, gravimetric moisture and herbaceous aboveground biomass differ significantly between the two areas. Principal coordinates analysis (PCoA) allows to infer that variables such as soil bulk density, penetration resistance and the abundance of V. caven species exhibit higher values in the area under gazing, while gravimetric moisture, aboveground biomass and abundance of P. affinis are higher in the area under livestock-excluded, showing that significant changes occur over just five years of livestock-excluded from the area.