Ferns and fern allies of Guatemala

Stolze, Robert G.

doi:10.5962/bhl.title.5639

Cited by 35 publications

(43 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Para a identificação e apresentação das espécies, no texto do trabalho foi adotado o Sistema de Classificação proposto por Kramer & Green (1990) e utilizadas as Chaves Analíticas contidas nos trabalhos de Sehnem (1967de Sehnem ( , 1968ade Sehnem ( , 1968bde Sehnem ( , 1970de Sehnem ( , 1971de Sehnem ( , 1972de Sehnem ( , 1974de Sehnem ( , 1979, Stolze (1976Stolze ( , 1981, Tryon & Tryon (1982), Proctor (1985), Mickel & Beitel (1988), Tryon & Stolze (1989a, 1989b, 1991, 1992, Moran & Riba (1995) e Kramer & Green (1990).…”

Section: Coleta Análise Identificação E Catalogação Das Espéciesunclassified

Pteridófitas ocorrentes em fragmentos de Floresta Serrana no estado de Pernambuco, Brasil

Xavier

Barros

2003

Rodriguésia

View full text Add to dashboard Cite

ResumoFoi realizado um levantamento florístico e análise de aspectos ecológicos das pteridófitas ocorrentes no brejo de Serra Negra em Bezerros, estado de Pernambuco, Brasil. Caracterizada como Brejo de Altitude ou Floresta Serrana, a área de estudo apresenta flora diferenciada da vegetação semi-árida que a cerca, por isso, os Brejos de Altitude, em especial a Serra Negra de Bezerros, atualmente estão sofrendo acelerado processo de devastação. Em um período de um ano, foram encontradas 31 táxons específicos, sendo a família Polypodiaceae a mais representativa com 46% dos registros. A espécie Trichomanes angustifrons (Fée) Wess. Boer destaca-se como novo registro para o Nordeste do Brasil. Os aspectos ecológicos que predominaram no brejo de Serra Negra de Bezerros foram o hábito herbáceo, o habitat rupícola, o tipo de ambiente mesófilo, a forma de vida hemicriptófita e os afloramentos rochosos como ambientes preferenciais. O fator condicionante da área ainda possuir certa diversidade específica, mesmo com a ampla restrição da mata nativa é que foram mantidas importantes condições ambientais necessárias para a sobrevivência da pteridoflora, como temperaturas baixas, umidade relativa do ar elevada e garoa noturna e matinal sempre presente. Palavras AbstractA floristic survey and analysis of ecological aspects of the pteridophytes occurring at the brejo of Serra Negra, Municipality of Bezerros, State of Pernambuco -Brazil, was conducted. The study site, characterized as Brejo de Altitude or Floresta Serrana, presents a flora that distinguishes itself from the surrounding semi-arid vegetation. Therefore, the Brejos de Altitude and particularly the Serra Negra of Bezerros are currently going through a very intense devastation process. Thirtyone specific taxa have been found in a period of a year, among which the Polypodiaceae is well represented comprising 46% of these registers. The species Trichomanes angustifrons (Fée) Wess. Boer stands out as a new register for Northeastern Brazil. The predominant ecological aspects observed at the brejo of Serra Negra of Bezerros were herbaceous habit, lithophytic habitat, a mesophylous type of environment, life form hemicryptophyte and the rocky formations as preferential environments. Despite the highly restricted native vegetation, the area still owns conditioning factors for the occurrence of a certain diversity of species. These factors are important environmental conditions such as low temperatures, high relative air humidity, and night and morning mist. These conditions have been maintained, and are important and necessary to the survival of the pteridophyte flora.

show abstract

Section: Coleta Análise Identificação E Catalogação Das Espéciesunclassified

Pteridófitas ocorrentes em fragmentos de Floresta Serrana no estado de Pernambuco, Brasil

Xavier

Barros

2003

Rodriguésia

View full text Add to dashboard Cite

show abstract

“…Mn III should be subject to a significant Jahn-Teller distortion for the reasons discussed above, but the effect may not have been observed because of the steric bulk of the -N(TMS) 2 3 (R ) C(CD 3 ) 2 Me, R′ ) 2,5-C 6 H 3 -FMe), 51 and chromium(III) trimesityl. 52 …”

Section: Low-coordinate Chromium Siloxidesmentioning

confidence: 99%

Low-Coordinate Chromium Siloxides: The “Box” [Cr(μ-Cl)(μ-OSi^tBu₃)]₄, Distorted Trigonal [(^tBu₃SiO)₃Cr][Na(benzene)] and [(^tBu₃SiO)₃Cr][Na(dibenzo-18-c-6)], and Trigonal (^tBu₃SiO)₃Cr

et al. 2005

View full text Add to dashboard Cite

Treatment of CrCl 2 (THF) 2 with NaOSi t Bu 3 afforded the tetrameric "box" [Cr(µ-Cl)(µ-OSi t Bu 3 )] 4 (1, X-ray). THF cleaved 1 to provide trans-(silox)ClCr(THF) 2 (2), whereas degradation of 1 with 4-picoline caused disproportionation and the generation of trans-Cl 2 Cr(4-pic) 2 and trans-(silox) 2 Cr(4-pic) x (n ) 2, 3; 3, 3-4-pic). Chromous centers in 1 were antiferromagnetically coupled, and density functional calculations on the high-spin (multiplicity ) 17) model [Cr-(µ-Cl)(µ-OH)] 4 (1′) revealed that its singly occupied 3d orbitals spanned an energy range of ∼2 eV. The addition of 8 equiv of Na(silox) to 1 yielded [( t Bu 3 SiO)Cr(µ-OSi t Bu 3 ) 2 ]Na‚C 6 H 6 (4, Y shaped, ∠OCrO(Na) ) 91.28(7)°), and treatment of 4 with dibenzo-18-crown-6 produced [(silox) 3 Cr][Na(dibenzo-18-crown-6)] (5, ∠OCrO ) ∼120°, (120 + R)°, (120 − R)°). Calculations of [( t Bu 3 SiO)Cr(µ-OSi t Bu 3 ) 2 ]Na (4′) and Cr(silox) 3-(5′) provided reasonable matches with the experimental geometries (X-ray). The trigonal chromic derivative (silox) 3 Cr (6) was synthesized from CrCl 3 -(THF) 3 for structural and calculational comparisons to the chromous derivatives.

show abstract

“…La nueva especie han sido así considerada después de comparar con las descripciones y claves de especies afines en distintos tratamientos taxonómicos para el Neotrópico, tales como: Gómez y Arbeláez 2009;Lellinger 1989;Mickel y Beitel 1988;Mickel y Smith 2004;Moran 1995;Murillo et al 2008;Smith 1981Smith , 1995Stolze 1981;Tryon y Stolze 1989, entre otros. La especie híbrida que aquí es aceptada como especie válida, es el resultado de las propias investigaciones de este autor y después de encontrar que esta entidad se encuentra en sitios donde los supuestos progenitores (uno o ambos) no están, por tanto, se comporta como especie; además, se encuentra más ampliamente distribuida en Costa Rica.…”

Section: Materiales Y Métodosunclassified

Novedades en Pteris L. (Pteridaceae) para Costa Rica.

Rojas-Alvarado

2018

abm

View full text Add to dashboard Cite

ResumenDos especies de Pteris L. para Costa Rica se describen aquí. Pteris arbelaeziana A. Rojas que difiere de P. muricatopedata A. Arbeláez porque tiene escamas del rizoma y estípite más largas, hoja pinnada y distribuido a elevaciones superiores. Pteris caridadae Testo & J. E. Watkins difiere de Pteris livida Mett. por sus escamas del rizoma y estípite más estrechas, las escamas del estípite densamente cubriéndolo todo, pinnas basales bifurcadas con la pinna basiscópica más pequeña y pinna apical más corta en relación con las laterales.Palabras clave: Pteris livida, Pteris muricatopedata, especies nuevas, Polypodiales, Pteridophyta. Abstract Novelties in Pteris L. (Pteridaceae) from Costa RicaTwo species of Pteris L. from Costa Rica is described here. Pteris arbelaeziana A. Rojas that differs from P. muricatopedata A. Arbeláez because it has longer rhizome and stipe scales, pinnate blade and distributed at high elevations. Pteris caridadiae Testo & J. E. Watkins differs from Pteris livida Mett. by its narrower rhizome and stipe scales, the stipe scales densely covering throughout, basal pinnae bifurcate with smaller basiscopic pinna and shorter apical pinna in relation with lateral ones.

show abstract

Ferns and fern allies of Guatemala

Cited by 35 publications

References 0 publications

Pteridófitas ocorrentes em fragmentos de Floresta Serrana no estado de Pernambuco, Brasil

Pteridófitas ocorrentes em fragmentos de Floresta Serrana no estado de Pernambuco, Brasil

Low-Coordinate Chromium Siloxides: The “Box” [Cr(μ-Cl)(μ-OSi^tBu₃)]₄, Distorted Trigonal [(^tBu₃SiO)₃Cr][Na(benzene)] and [(^tBu₃SiO)₃Cr][Na(dibenzo-18-c-6)], and Trigonal (^tBu₃SiO)₃Cr

Novedades en Pteris L. (Pteridaceae) para Costa Rica.

Contact Info

Product

Resources

About

Ferns and fern allies of Guatemala

Cited by 35 publications

References 0 publications

Pteridófitas ocorrentes em fragmentos de Floresta Serrana no estado de Pernambuco, Brasil

Pteridófitas ocorrentes em fragmentos de Floresta Serrana no estado de Pernambuco, Brasil

Low-Coordinate Chromium Siloxides: The “Box” [Cr(μ-Cl)(μ-OSitBu3)]4, Distorted Trigonal [(tBu3SiO)3Cr][Na(benzene)] and [(tBu3SiO)3Cr][Na(dibenzo-18-c-6)], and Trigonal (tBu3SiO)3Cr

Novedades en Pteris L. (Pteridaceae) para Costa Rica.

Contact Info

Product

Resources

About

Low-Coordinate Chromium Siloxides: The “Box” [Cr(μ-Cl)(μ-OSi^tBu₃)]₄, Distorted Trigonal [(^tBu₃SiO)₃Cr][Na(benzene)] and [(^tBu₃SiO)₃Cr][Na(dibenzo-18-c-6)], and Trigonal (^tBu₃SiO)₃Cr