The clonal tank‐bromeliad Aechmea bromeliifolia (Rudge) Baker was found in four different habitats in a restinga (vegetation mosaic on sandy coastal plains), of south‐eastern Brazil. These habitats (swamp forest, dry forest, dry shrubland and herbaceous marsh) lie within a few hundred metres of each other along a gradient extending inland from the coast, and differ markedly in terms of light and flood regime. We compared ramet morphology, leaf anatomy and physiology, and population parameters to examine the amplitude of trait variation of this widespread species in the studied restinga. This integrated approach allowed us to examine which variation conferred acclimation and which was merely a stress symptom. A. bromeliifolia showed site‐specific differences in abundance, distribution, rosette size and shape, leaf anatomical arrangement and photochemical efficiency (potential quantum yield; Fv/Fm) during the day. Most of the variation found seemed to be related to the interaction of light and flooding. The lowest number and size of ramets at the exposed, dry shrubland was matched by a marked leaf photoinhibition, which suggested poor acclimation to local levels of light intensity and limited water supply. In the other habitats, the morpho‐physiological parameters measured suggested adequate foraging behaviour and site acclimation. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 2002, 140, 391‐401.

RESUMO: "Etnobotânica urbana em Petrópolis e Nova Friburgo (Rio de Janeiro, Brasil)". O principal objetivo desse trabalho foi estudar as plantas úteis comercializadas em feiras livres em Petrópolis e Nova Friburgo, Rio de Janeiro, Brasil. Os dados foram coletados utilizando as técnicas de observação participante, entrevistas semi-estruturadas e listagem livre com quatro comerciantes de plantas medicinais. A partir dessas entrevistas, 115 espécies (pertencentes a 49 famílias) foram relacionadas: 94 com uso medicinal, 12 com uso religioso e 9 com uso ornamental. Trinta por cento das espécies são nativas e 72% possuem hábito herbáceo. As famílias mais representativas foram Asteraceae (26 espécies) e Lamiaceae (10 espécies). As espécies medicinais indicadas para o tratamento de doenças do sistema respiratório foram mais freqüentes durante o outono e inverno. A espécie denominada como Espinheira-santa (Clarisia cf. ilicifolia) obteve o valor mais alto de Importância Relativa (1,8) e a mais alta colocação em todas as estações do ano utilizando o cálculo Preference Ranking, embora seus níveis de eficiência e toxidez não tenham sido ainda estabelecidos. O estudo se mostrou relevante, pois visa reunir o conhecimento dos informantes sobre as espécies que comercializam em feiras livres e mercados populares no estado do Rio de Janeiro, que representa uma valiosa fonte para a bioprospecção.Unitermos: Etnobotânica, plantas medicinais, feira-livre, conhecimento local, Brasil. ABSTRACT:The main goal of this paper was the study of the useful plants sold in the openair fairs of Petrópolis and Nova Friburgo, Rio de Janeiro, Brazil. Data collection was obtained through participant observation, semi structured interviews and free listing with four herbalist informants. From the interviews, 115 species (belonging to 49 families) were recorded: 94 for medicinal purposes, 12 with religious application, and 9 for ornamental purposes. Thirty percent of the species were native, and 72% herbaceous. The most representative families were Asteraceae (26 species) and Lamiaceae (10 species). The medicinal species related to diseases of the respiratory system were more common during the winter and autumn. "Espinheirasanta" (Clarisia cf. ilicifolia) had the highest Relative Importance (1.8) and collocation in all seasons using the Preference Ranking, although its effectiveness or toxicity levels have not been established. The importance of the study is to gather knowledge from local herbalists about commercialized species in open-air fairs and popular markets in the Rio de Janeiro State, which represent valuable resources for bioprospection.

A molecular phylogeny for the subfamily Pitcairnioideae was inferred to examine the distribution of crassulacean acid metabolism in the subfamily. For this purpose, a neighbour‐joining tree with p‐distances was built using a MatK chloroplast gene data set. The phylogenetic results of our analysis confirmed the monophyletic condition of most genera examined: Brocchinia, Dyckia, Encholirium, Fosterella, Hechtia and Puya. A paraphyletic basal sequence showed Hechtia branching off from the basal node, followed by Brocchinia, Cottendorfia + Navia phelpsiae, and Puya. The remaining taxa were divided into two groups: (a) Deuterocohnia meziana, Dyckia, Encholirium; Fosterella; Deuterocohnia spp. + Pitcairnia heterophyla; (b) Pepinia, Pitcairnia spp. and Navia igneosicola. The basal placement of the CAM genera Hecthia indicates that CAM may be a ‘primitive condition’ in Pitcairnioideae and that C3 species may have lost the ability to induce CAM. In this molecular tree, CAM metabolism appeared scattered throughout the tree. Current knowledge, however, does not exclude the possibility that CAM arose only once and it has been switching on and off in various lineages. Further detailed studies on photosynthetic metabolisms and the phylogenetic distribution of characters will provide a better basis on which to evaluate photosynthetic origins. © 2003 The Linnean Society of London, Biological Journal of the Linnean Society, 2003, 80, 261–268.

Abstmct:The restingo comprises coastal vegetation formations which dominate the Atlantic seaboard of Brazil. Exposed sand ridges and associated lagoon systems have poorly developed soils subject to pronounced water deficits. Distinct vegetation zones support a high diversity of life forms, and a comparative study has been undertaken to investigate interactions between degree of exposure, nutrient supply and photosynthetic pathway (C,, or CAM) in selected species across the restinga. A number of species occurring throughout the restinga were chosen as representative species of different life forms, comprising C, pioneer shrubs (Eugenia rotundifolio and Erythroxylurn ovalifolium). impounding (tank) terrestrial bromeliad (Neoregelia cruenta: CAM) and the atmospheric epiphyte (Tillandsia stricta: CAM). Comparisons of plant and soil nutrient composition, and airborne deposition were conducted for each zone. Soil nutrient content and organic matter were closely related, reaching a maximum in zone 4. the seaward face of the inner dune. Salt concentration in leaves was independent of atmospheric deposition for the terrestrial species, in contrast to the atmospheric epiphyte T. stricta. In the slack area, vegetation formed characteristic "islands" with the soil beneath enriched in nutrients, suggesting a complex interplay between plants and soil during the development of vegetation succession. Here, two additional trees were investigated, C, and CAM members of the Clusiaceae. respectively Clusia lanceolata and C. flurninensis. Stable isotope composition of nitrogen (815N) was generally more negative (depleted in 15N) in plants with low total nitrogen content. This was exemplified by the atmospheric bromeliad. T. stricta. with an N content of 2.91 g/kg and 615N of -12.3 per mil. Stable isotopes of carbon (813C) were used to identify the distribution of photosynthetic pathways, and while the majority of bromeliads and orchids were CAM. analysis of the soil organic matter suggested that C3 plants made the major contribution in each zone of the restinga. Since 613C of plant material also suggested that water supply was optimal in zone 4, we conclude that succession and high diversity in the restingo is dependent on exposure, edaphic factors, and perhaps a critical mass of vegetation required to stabilize nutrient relations of the system.

A comparison of carbon isotope discrimination characteristics, crassulacean acid metabolism (CAM) activity and gas exchange together with concurrent analysis of photosystem II (PSII) chlorophyll fluorescence was conducted on leaves of sympatric species of Clusia from the restinga of Barra de Maricá, Brazil. The carbon isotope discrimination (Δ) and leaf-sap titratable acidity for leaves collected in the field indicated that the carbon metabolism of one species, C. lanceolata, was predominantly C3-like, and a second, C. fluminensis, constitutive CAM. When well-watered under glasshouse conditions C. lanceolata displayed a gas exchange pattern expected of a C3 plant, where values of instantaneous discrimination (Δ) rose from 13.5% shortly after dawn to 21.9‰ at midday, suggesting that all CO uptake was mediated solely by ribulose 1,5-bisphosphate carboxylase (RUBISCO). C. fluminensis showed a gas exchange pattern which clearly exhibited all four phases of CAM. Δ values during phase II ranged from -0.4‰ at dawn to 5.9‰ some 3 h later, indicating that C4 carboxylation dominated CO uptake during the morning with an increasing contribution by RUBISCO, suggested by the 5‰ shift in Δ at this time. The dominance of phosphoenol-pyruvate carboxylase (PEPc) activity was also found during phase IV, and extended throughout the dark period (phase I) in C. fluminensis, such that values of Δ measured were negative (-5.0 to -0.4‰). This is the first time that negative Δ values have been reported, close to those predicted theoretically for PEPc activity. The day-time uptake of CO mediated by PEPc could lead to futile cycling through RUBISCO. In C. fluminensis organic acids were subjected to carbon turnover between PEPc and RUBISCO during phase II of CAM, serving perhaps to dissipate ATP and reductant at a time when excess photons are absorbed. Under low levels of photosynthetically active radiation (PAR) the two species displayed similar chlorophyll fluorescence characteristics, although for the CAM C. fluminensis a lower rate of decarboxylation of acids in the afternoon was reflected in changed quenching capacity. Under high PAR both species responded directly to changes in incident radiation, reflected by decreases in photon use efficiency (ΦPSII) and the intrinsic photochemical efficiency (F /F), together with high and reversible quenching of excess light by the means of radiationless or thermal dissipation (q ). Both species, with such markedly different carboxylation characteristics achieve similar rates of electron transport and maintain photosynthetic integrity. Under field conditions, however the severity of a prolonged dry season caused the CAM species to become deciduous, whereas the "C3-like" species remained healthy. This suggests that the widely expected advantages of CAM do not extend to tolerance of extreme environmental conditions, in contrast to the more C3-like of these sympatric species.

-(Pollen viability of Carica papaya L.: a methodological comparison). Pollen viability of Carica papaya L. 'Sunrise Solo' cultivar was estimated using in vitro germination and pollen stain tests. Two culture media described in the literature as efficient for pollen in vitro germination of C. papaya were used. Germination was higher in the media without essential elements but with a higher concentration of agar (65% compared with 51.5%). These results were compared with viability estimates based on staining pollen. The five stains used to test for pollen viability were: 2,3,5-triphenyl tetrazolium chloride -TTC, Alexander's stain, acetocarmine, iodine-potassium iodide and Sudan IV. Pollen viability estimated with TTC was 67.5% and similar to germination results providing a reliable estimate of in vitro germination. The four other stains overestimated pollen viability (> 90%), and their use should be restricted to determining cell constituents, and pollen grain integrity.

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