-(Leaf anatomy of Brazilian species of Aechmea subgenus Chevaliera (Gaudich. ex Beer) Baker, BromelioideaeBromeliaceae). The subgenus Chevaliera comprises 21 species most of them occuring in several Brazilian ecosystems. In order to expand the taxonomic knowledge of this subgenus, data on the leaf anatomy of 11 species is presented. Among the characters which were described in this study, the most relevant ones are: stomata position, the thickeness of the substomatic chamber cells, hypodermis, number of layers of the water storage tissue, the shape of the cells that form air channels and the distribution of the fibers in the mesophyll.

-(Primary and secondary development of Cyperus giganteus Vahl rhizome (Cyperaceae)). In Cyperus giganteus, like in other Monocotyledoneae, the protoderm, procambium, fundamental meristem and primary thickening meristem (PTM) are differentiated from the rhizome promeristem. The PTM produces the inner cortical parenchyma, endodermis, pericycle and amphivasal vascular bundles, which are formed by the procambium too. After the primary body differentiates, cellular divisions continue only in the pericycle, and originate an irregular vascular system with vessel elements shorter and more branched than those found in the primary growth. This change of activity in the pericycle defines a secondary growth, where the secondary thickening meristem (STM) is the pericycle itself.RESUMO -(Desenvolvimento primário e secundário do rizoma de Cyperus giganteus Vahl (Cyperaceae)). Em Cyperus giganteus, como em outras monocotiledôneas, a partir do promeristema do rizoma diferenciam-se a protoderme, o procâmbio e o meristema fundamental e, ainda, o meristema de espessamento primário (MEP). Este último dá origem ao parênquima cortical interno, endoderme, periciclo e feixes vasculares anfivasais, os quais se formam também a partir do procâmbio. Após a diferenciação do corpo primário, apenas o periciclo permanece em divisão, formando um sistema vascular desalinhado, onde os elementos de vaso são mais curtos e mais ramificados do que aqueles do crescimento primário. Esta mudança de atividade do periciclo caracteriza o crescimento secundário, cujo meristema de espessamento (MES) é o próprio periciclo.

The aim of this work was to study morphological and biochemical aspects during zygotic embryogenesis in O. catharinensis, by measuring changes in the endogenous concentrations of proteins, amino acids, polyamines (PAs), indole-3-acetic acid (IAA) and abscisic acid (ABA). Buffer-soluble and insoluble protein contents were determined by spectrometry, and amino acids, PAs, IAA and ABA concentrations were determined by high performance liquid chromatography. Total amino acid accumulation, predominantly asparagine, occurred when the embryo showed completely developed cotyledons, with posterior reduction in the mature embryo. This decrease in total amino acid concentration in the mature embryo may result from their use in storage as well as for LEA protein synthesis. Free putrescine (Put) concentration decreased, while free spermine (Spm) increased during embryo development. This suggest a role for Put in the initial phases of embryogenesis when high rates of cell division occur, while elevated concentration of Spm are essential from the middle to the end of embryo development, when growth is mainly due to cell elongation. An IAA peak in zygotic embryos occurred during initial development, suggesting a link between growth and cellular division as well as with the establishment of bilateral symmetry. ABA concentration declined during initial stages of development then increased at the mature embryo stage, suggesting a possible relationship with dormancy and recalcitrance characteristics. Our results show that changes in the phytohormones (IAA, ABA and PAs) concentrations in combination with amino acids are likely important factors determining the developmental stages of O. catharinensis zygotic embryos.

-(Development, structure and distribution of colleters in Mandevilla illustris and M. velutina (Apocynaceae)). Colleters of Mandevilla illustris and M. velutina are present on the cotyledons, shoot apices, mature leaves and on the nodal region, where they are interpetiolar and intrapetiolar. In M. velutina there are two colleters on the adaxial basal part of the leaf blade, and in M. illustris, this number varies. The differentiation of the colleters occurs in the early stages of leaf development. When colleters are mature, they consist of a long head on a short stalk. The central core of the colleter is made up of parenchymatous cells that may exhibit phenolic compounds and is surrounded by radially elongated epithelial cells. The foliar and intrapetiolar colleters can exhibit vascularization. The colleters produce a translucient sticky substance that reacts positively to polysaccharides and, before senescence, they produce lipophilic substances. The Mandevilla colleters data can give support to the taxonomy and phylogeny of the Apocynaceae.RESUMO -(Desenvolvimento, estrutura e distribuição de coléteres em Mandevilla illustris e M. velutina (Apocynaceae)). Coléteres de Mandevilla illustris e M. velutina estão presentes nos cotilédones, ápices caulinares, folhas maduras e na região nodal, onde estes são interpeciolares e intrapeciolares. Em M. velutina existem dois coléteres na face adaxial da base da lâmina foliar, porém, em M. illustris este número varia. A diferenciação dos coléteres ocorre nos estágios iniciais do desenvolvimento foliar. Quando os coléteres estão maduros, eles consistem de uma longa cabeça sobre um curto pedúnculo. A porção central do coléter é constituída de células parenquimáticas que podem apresentar compostos fenólicos e é envolvida por células epiteliais radialmente alongadas. Os coléteres foliares e intrapeciolares podem exibir vascularização. Os coléteres produzem uma substância pegajosa e translúcida que reage positivamente para polissacarídeos e, antes da senescência, eles produzem substâncias lipofílicas. As informações obtidas sobre os coléteres das Mandevilla podem fornecer subsídios aos estudos taxonômicos e filogenéticos das Apocynaceae.

(Taxonomic applications of leaf anatomy of the Brazilian species of Hypolytrum Rich. (Cyperaceae)). Hypolytrum Rich. (subfamily Mapanioideae) has a pantropical distribution being represented in the Neotropics by 16-21 species, most of them growing in several Brazilian ecosystems. Informations from foliar anatomy was analysed for 10 species of the genus. The most useful characters detected in Hypolytrum species studied here are: the shape of the leaves in cross section, the occurrence of granules (probably formed by silica) on the epidermal cells; features of the cuticle, the hypoderm and the aerenchymatous parenchyma; the number of layers and origin (hypodermal and epidermal) of bulliform cells; the presence of papillae on the abaxial face of the epidermis; and occurence of radiate parenchyma on the smaller bundles. Studies of foliar anatomy showed to be useful in generic and specific delimitation but do not support the taxonomic sections established.RESUMO (Aplicações taxonômicas da anatomia foliar das espécies brasileiras de Hypolytrum Rich. (Cyperaceae)). Hypolytrum Rich. (subfamília Mapanioideae) tem distribuição pantropical e está representado por 16-21 espécies na região Neotropical, das quais grande parte ocorre no Brasil habitando diferentes ecossistemas. São apresentados dados de anatomia foliar com maior relevância taxonômica para 10 espécies do gênero. Entre eles, destacam-se: formato da folha em secção transversal; presença de grânulos, provavelmente de sílica, em células epidérmicas; aspectos da cutícula, da hipoderme e do parênquima lacunoso; número de camadas e origem (hipodérmica e epidérmica) das células buliformes; presença de células epidérmicas papilosas; e ocorrência de parênquima radiado nos feixes menores. Os estudos de anatomia foliar mostram-se relevantes na delimitação genérica e específica, porém não apoiam as secções taxonômicas estabelecidas.