Pirani J.R.,University of Sao Paulo |
Prado J.,Institute Botanica
Taxon | Year: 2012
"Embryophyceae" and Equisetopsida have been used recently to designate the land plants at the rank of class. The former was never validly published. In this paper we propose a new name in the rank of class-Embryopsida Engler ex Pirani & J. Prado-, to replace Equisetopsida C. Agardh, which was used by Chase & Reveal (2009) to apply to all land plants. The new name here proposed follows Art. 16.1(b) of both the Vienna Code and the Melbourne Code and recognizes Adolf Engler's use of the term "Embryophyta" to name the land plants, i.e., all plants provided with an embryo.
Benatti M.N.,Institute Botanica
Mycology | Year: 2012
Bulbothrix pseudofungicola and B. silicisrea are two new lichen species discovered during a systematic revision of the genus; both containing gyrophoric acid as a medullary substance. © 2012 Copyright 2012 Mycological Society of China.
Benatti M.N.,Institute Botanica
Mycology | Year: 2011
Bulbothrix caribensis and B. lyngei are two new lichen species discovered during a systematic revision of the genus. The first species lacks medullary substances and the second species produces an undetermined fatty acid. © 2011 Copyright 2011 Mycological Society of China.
Esteves L.M.,Institute Botanica
Anuario do Instituto de Geociencias | Year: 2013
The spores of ferns and lycophytes may be deposited on the soil, and by various mechanisms, they can be moved down into and through the soil, although usually remaining in the superficial layers. They may persist in the soil for some time in a dormant state, and when brought back to the surface they will germinate. Such living spores stored in the soil comprise what is called a soil spore bank. Spore banks can reduce the risk of extinction of species, allowing the regeneration of a population in an area devastated by floods, fires, droughts, landslides or succession processes. Thus, they have a function similar to that of seed banks in spermatophytes. In the majority of ferns and lycophytes the spores are positively photoblastic. This has adaptive value since it makes them dormant when buried and potentially able to germinate when brought to the surface. The regeneration of persistent spore banks can also increase the possibilities of crossing between gametophytes of colonizing species. They also function as a buffer against the consequences of low spore production in years with adverse weather conditions, and against drastic changes in the genetic composition during fluctuations in population size, such that only long-term changes in the environment can substantially alter its composition. Moreover, genotypes that were apparently lost can be recovered from the spore bank.
Luz C.F.P.D.,Institute Botanica
Grana | Year: 2016
Ephedra tweediana is one of few gymnosperms native to Brazil and the sole species of the Ephedraceae family. The present work examines the pollen grains of E. tweediana using light and scanning electron microscopy in order to obtain additional morphological data and to help to identify it in its fossil forms. Ephedra tweediana pollen grains are monad, medium sized, ellipsoidal, inaperturate, characterised by a series of psilate longitudinal ridges (or plicae), typically ten, with small polar apices that protrude. The wide gently domed ridges are straight and psilate, separated by a psilate region (furrows) with a distinct, unbranched, slightly undulating hyaline line formed by the thinning of the sexine located in the middle of the furrow area. The granular sexine at the crest of a plica is composed of a homogeneous tectum, below which an infratectum is apparent. The infratectum disappears into the furrows. The nexine is uniform in thickness in all regions. Pollen of E. tweediana is characterised by the merging of the Steeves and Barghoorn’s Type C and D. However, occasional pollen grains of the Type B occur with undulant ridges. The pollen grains of E. tweediana resemble those of E. trifurca and E. chilensis (syn. E. andina in Steeves and Barghoorn’s work). Few pollen grains resemble the E. chilensis presented by these authors in Type B. This similarity hinders the identification of these American species in sediments containing microfossils. © 2015 Collegium Palynologicum Scandinavicum.