Resumo em Inglês:

ABSTRACT A palynological study of six species of Pterospermum was conducted to investigate variation in pollen micromorphological characteristics. The studied species were P. diversifolium, P. elongatum, P. jackianum, P. javanicum, P. lanceifolium and P. subpeltatum. Pollen was subjected to acetolysis, single-grain techniques and dehydration series, and observed using light and scanning electron microscopy. The results reveal some common characters shared by all the studied species, namely: echinate-granulate exine ornamentation; porate pollen class; and circular amb. Variation was found in the ratio of exine thickness, pollen size, and average spine length, outline, shape, measurements, spine size and the presence of an annulus. These characters proved to be valuable for identifying and differentiating the studied species. This study shows that morphological characteristics of Pterospermum pollen have taxonomic value, especially for the identification and differentiation of species of the subfamily Dombeyoideae and even other Malvaceae s.l.

Resumo em Inglês:

ABSTRACT Taxonomic investigations of phytoplankton community structure are very important for understanding the dynamics of these organisms in places like reefs, which present broad hydro-biological variation. This study aimed to determine and investigate phytoplankton community composition and biomass in natural pools of Atol das Rocas (3°51’ S; 33°49’ W), and to evaluate the possible influences of abiotic variables throughout different seasons. The oceanographic parameters used to assess the phytoplankton community and its biomass were chlorophyll a, salinity, water temperature, dissolved oxygen and dissolved inorganic nutrient content, namely ammonia, nitrate, nitrite, phosphate and silica. A total of 109 species were identified, distributed among four groups: Ochrophyta (52.3 %), Dinophyta (37.6 %), Cyanobacteria (7.33 %) and Haptophyta (2.75 %). Although none of the hydrological parameters were found to be statistically determinant, phytoplankton composition in all the studied pools was primarily associated with nutrient salts and there was a qualitative and quantitative increase in phytoplankton in the rainy season. This increase was due to the positive relationship between phytoplankton composition and nutrient salts when associated with local hydrodynamics, which provides more favorable conditions for the enrichment of diversity with emphasis on species that compose the benthic microflora.

Resumo em Inglês:

ABSTRACT The Atlantic Forest contains more bryophyte species and greater endemism than any other Brazilian phytogeographic domain. We analyzed the bryoflora of an Atlantic Forest remnant along the southern Brazilian coast to examine: (i) floristic composition, species richness, life forms and bryocenological groups in different phytophysiognomies (humid lowlands, sandy Restinga forests, and swampy Restinga forests); (ii) floristic similarities among them; and, (iii) the influence of substrate types on bryophyte species richness and floristic composition. Sandy Restinga forest had the greatest species richness. Approximately 75 % of the species and 42 % of the families were not shared among phytophysiognomies. The predominant life form was mat (46 %) and the predominant bryocenological group was corticolous (69 %). Elevated floristic differentiation was observed among the different phytophysiognomies (Jaccard values <0.35) and among the different substrates sampled (<0.2). The floristic uniqueness found among the different physiognomies in the present study demonstrates the importance of studying the diversity and conservation of all Atlantic Forest phytophysiognomies. The evaluation of bryophytes to delimit and manage protected areas can contribute to effective protection of the entire biodiversity spectrum. In addition to their important ecological roles, bryophytes are useful bio-indicators and valuable tools for monitoring, conserving, and restoring ecosystems.

Resumo em Inglês:

ABSTRACT Snow Island is part of the South Shetland Archipelago in Antarctica. Most of its surface is permanently covered by snow, yet it has an important paleobotanical site. There are no protected areas on the island and no recent data regarding its vegetation. This study aimed to collect and identify fresh samples of bryophytes from President Head Peninsula of Snow Island. Samples were collected during the summers of 2015 and 2018. Among the 24 bryophyte species identified in this work, 19 are new occurrences for Snow Island, bringing the total known for the island to 29 species. The most diverse family is Pottiaceae, with four species of two genera, followed by Bryaceae and Polytrichaceae, with three species each. The results show that the diversity of mosses on Snow Island is greater than previously reported. We here demonstrated the region's importance and the 190 % increase in Snow Island species number. This study also updated the Antarctic distribution of some species.

Resumo em Inglês:

ABSTRACT Solanaceae is represented by herbs, shrubs, trees and climbing plants and has cosmopolitan distribution, with a large number of native species in the Neotropical region. This study aimed to characterize the pollen morphology of ten species of Solanaceae (especially species of Cestrum and Solanum) from Cerrado forest fragments in Brazil, in order to contribute to the palynology, taxonomy and conservation of degraded areas. Pollen grains were acetolysed, measured and photographed using light and scanning electron microscopy. Qualitative data were described, and quantitative data were analyzed statistically according to sample size. Morphologically, the studied pollen grains vary in size (small to medium), amb (subcircular to subtriangular), shape (oblate spheroidal to subprolate), aperture details (very long, long or narrow colpi, rounded or tapered at the polar ends, colpi with margo, sometimes with a fastigium, endoapertures can present costa and median constriction) and ornamentation (psilate, rugulate, striate or microreticulate). We observed rugulate or striate pollen grains without fastigium for Cestrum species, whereas psilate or microreticulate pollen grains with fastigium were observed for Solanum species. Qualitative data on diameters and aperture measurements were also found to be important in characterizing the two genera. The results obtained here confirm Solanaceae as an eurypalynous family.

Resumo em Inglês:

ABSTRACT High species diversity, large area, and taxonomically under-studied groups are some of the explanations for the frequent discovery of new species of plants during ecological field campaigns in the Amazon region. Some of these new species are already being threatened from unplanned urban expansion associated with deforestation and habitat loss. Here we describe Tovomita cornuta, a new species discovered during ecological studies in the white-sand campinaranas of the Amazon, which is also threatened. The species is endemic to the state of Amazonas, Brazil, where it occurs in the understory of forested campinaranas physiognomies and is easily recognized by its narrowly obovoid fruits with dilated free styles. We provide a description, taxonomic and ecological comments, assessment of conservation status, geographic distribution, phenology, and illustrations for the new species.

Resumo em Inglês:

ABSTRACT During taxonomic studies of extra-Amazonian species of Heisteria, a new record (Heisteria maytenoides) and new species (Heisteria longipedicellata) from the Atlantic Forest of Espírito Santo were identified. Morphological descriptions, illustrations, the geographic distribution, and conservation status are provided for these species; an identification key for species of Heisteria of the state is also presented. Heisteria longipedicellata is known only from the type locality and recognized mainly by the long pedicel of the fruits (ca. 67 mm long). It is morphologically similar to H. blanchetiana, however, it differs by the length of the pedicel in fruit, diameter of the accrescent calyx in fruit and drupe size. Heisteria maytenoides, until now registered only in the phytogeographic domain of the Amazon in Colombia and Venezuela, had its distribution confirmed to Brazil, in the phytogeographic domain of the Atlantic Forest, in the state of Espírito Santo; it is recognized mainly by its coriaceous leaves and globoid fruits. In this study the richness of Heisteria for the Espírito Santo state is updated to five species. Heisteria blanchetiana, previously registered only to the state of Bahia, had its distribution expanded to include Espírito Santo.

Resumo em Inglês:

ABSTRACT Arbuscular mycorrhizal fungi (AMF) and dark septate fungi (DSF) are symbionts that are associated with the roots of plants, including epiphytic lycophytes and ferns. Paris-type mycorrhiza and glomoid structures are the most common forms of colonization in these plants. This work aimed to evaluate the occurrence of these symbionts in the roots of epiphytic lycophytes and ferns as well as the diversity of AMF spores recovered from substrate associated with the roots of eleven species. Roots of Asplenium gastonis, Campyloneurum aglaolepis, C. nitidum, Niphidium crassifolium, Pecluma pectinatiformis, Phlegmariurus mandiocanus, Pleopeltis hirsutissima, P. pleopeltifolia andSelaginella microphyllahad hyphae and vesicles typical of AMF colonization, but not arbuscules.Campyloneurum nitidum, Pecluma pectinatiformis, Phlegmariurus mandiocanus, Pleopeltis pleopeltifolia and Selaginella microphyllahad melanized hyphae and microsclerotia typical of DSF. All species colonized by DSF were also colonized by AMF. Seventeen spore morphotypes of AMF were identified, of which six were acaulosporoid and eleven glomoid. Glomus aff. formosanum andAcaulospora aff. lacunosa were the most abundant and frequent species. Epiphytic lycophytes and ferns host concurrently AMF and DSF but colonization is scanty in their roots. For the first time, acaulosporoid spores and intraradical vesicles are reported for this group of plants.

Resumo em Inglês:

ABSTRACT A new species of Xyris endemic to Southern Brazil is described. Xyris serrana is placed in X. sect. Nematopus, which is characterized by having basal, suprabasal, or central placentation. The new species is known from few samples from the summits of Serra Geral, in Santa Catarina State. According IUCN criteria, the conservation status of the species is evaluated as Data Deficient. Xyris serrana is morphologically similar to X. neglecta due to both having narrowly flattened blades and young bracts with villous-ciliate margins, but differs by its yellowish-brown sheaths, blackish-brown bracts with a narrow macula, and lateral sepals with reddish trichomes. A description, illustration, distribution map, and taxonomic comments are provided.

Resumo em Inglês:

ABSTRACT Determination of the chromosome base number of a taxon is fundamental to understanding karyotypic variation and its implications for the evolution of that group. This usually requires careful evaluation of cytological literature and robust phylogenetic support. The base number for the family Rutaceae (x = 9 or x = 18) has long been the subject of debate. Here, we analyzed the banding pattern, rDNA sites, and genome size of Dictyoloma vandellianum, subfamily Cneoroideae, the sister group of the remaining Rutaceae, and revised critical points about the chromosome base number of the family. We found that this species has n = 9, which differs from the n = 18 possessed by other cytologically known Cneoroideae species. Thus, n = 9 occurs in the main clades of Rutaceae and is the most probable base number of the family. The hypothesis of x = 18 as the base number is no longer sustainable, although n = 18 is very common in Rutaceae. Moreover, the fluorescent banding pattern and the relatively large genome size (1C = 1.3 pg) of D. vandellianum suggest that its chromosomal organization is highly divergent from Aurantieae, the only large Rutaceae clade where species with n = 9 are greatly dominant.

Resumo em Inglês:

ABSTRACT We investigated the pollen morphology of eight species of Acalypha occurring in Bahia State, Brazil. Flower buds were collected from specimens deposited in the CEPEC and HUEFS herbaria. Pollen samples were acetolyzed and analyzed using both light and scanning electron microscopy. The pollen grains examined using optical microscopy were found to be small and brevicolporate, with three to six apertures and elevations and fastigium, and had a psilate to scabrate exine. Scanning electron microscopy revealed the presence of supratectal elements and Ubisch bodies, and evidenced three pollen types based mainly on exine ornamentation: microrugulate-scabrate (slightly rugulate-scabrate), areolate-rugulate, and microechinate. This study provides new data and new interpretations of pollen morphology for the genus Acalypha, with comments on the palynological relationships between Acalypha and its sister group Mareya, and the next most closely related genus (Spathiostemon).

Resumo em Inglês:

ABSTRACT Intraspecific variation in floral traits, such as nectar, could lead to differences in the identity and pollinator effectiveness of visitors between populations of a flowering plant. We studied the bat-pollinated bromeliad species Pseudalcantarea viridiflora to determine whether there are differences in the identity of its pollinators and in its nectar traits between two study sites located at different latitudes in Veracruz, Mexico. We studied phenology and determined the volume, concentration and quantity of dissolved sugars in the nectar at both sites. The northern P. viridiflora population produced nectar that was more sugar-rich, leading to pollination by a larger species, Anoura geoffroyi, whereas the southern populations were visited mainly by Glossophaga mutica, a smaller pollinator. The most abundant nectarivorous bats at each site differ in terms of their efficiency as pollinators, and we suggest that this might affect their contribution to the fitness of the bromeliad.

Resumo em Inglês:

ABSTRACT Phytoplankton is formed by photosynthesizing microorganisms that act as primary producers in distinct water bodies. These include microalgae and cyanobacteria. It is essential to know the phytoplankton in water catchment areas intended for drinking water treatment once their excessive density may result in problems, such as taste and odor in the water, toxin production, filter clogging, and other damages. This study investigated the phytoplankton dynamics and the environmental factors that may influence phytoplankton density in the drinking water catchment zone of Macapá, a city located on the Amazon River mouth. The sampling was carried out monthly from April/2015 to March/2016. The study reports the first detailed information on the phytoplankton in the study area since previously published studies regarded only cyanobacteria. The species Limnothrix planctonica and Aulacoseira granulata may substantially influence the water treatment due to their great abundance in the study area, especially in July and November, when their density peaks occur, respectively. Nevertheless, Aulacoseira granulata is the primary constituent of the phytoplankton biovolume. This study provides biological and sanitary information to guide public administration towards improving the quality and safety of water supply services, and also to increase the biodiversity knowledge of Amazonian phytoplankton.

Resumo em Inglês:

ABSTRACT Reports of the angiosperm macrofossils from the Early Cretaceous sediments of India are relatively poor, with only one report from the Krishna-Godavari Basin. The present study documents a monocotyledon leaf fossil from the Barremian-Aptian (Early Cretaceous) of Gangapur Formation, Pranhita-Godavari Basin, India. The present fossil leaf placed under a new genus Sahniophyllum and it is characterised by the ribbon shaped leaves, with parallel venation, arranged in rosette form suggests its probable affinity with Hydrocharitaceae. The taphocoenosis demonstrates its autochthonous preservation and aquatic habitat.

Resumo em Inglês:

ABSTRACT Distyly is a floral polymorphism that promotes cross-pollination through precise pollination. Psychotria is a mostly tropical genus of distylous Rubiaceae. Although widely studied in Brazil, some regions/species are still poorly explored, which hinders the understanding of distyly system along a greater geographical range. Here, we studied a subtropical population of Psychotria brachyceras in southern Brazil. For this, we characterized morphs occurrence, reciprocity of sexual structures, mating and incompatibility systems. In addition, we compared the reciprocity values from other species of the genus based on values gathered from literature to understand how the population behaves. The population showed equal proportions of thrum (short stigma/high anthers) and pin (high stigma/short anthers) morphs. Reciprocity was higher than the average for the genus and inaccuracy values between sexual organs were evenly distributed between the organ types, indicating a trend to typical distyly. Higher fruit set rates in intermorph and open pollination treatments and pollen tube growth observations confirmed that the population has a functional heteromorphic incompatibility system. Psychotria brachyceras showed no signs of distinct traits to typical distylous populations, which seems to ensure reproductive success and distyly maintenance.

Resumo em Inglês:

ABSTRACT In tropical semi-deciduous forests, where 20-50 % of canopy trees shed their leaves in the dry season, species with varying degrees of leaf deciduousness share the same space and resources. Here, we describe the tree community in a 10.24-ha plot to assess whether small-scale variation in canopy structure and soil conditions are associated with changes in tree community structure, diversity, and composition. We sampled 11,585 individuals with diameter at breast height ≥ 4.8 cm belonging to 146 species. Plot density (1,129 trees ha-1) and basal area (24.81 m2 ha-1) were smaller than other similar forests, which may be due to an old wind disturbance. For 8.96 ha, we evaluated the relationship between abiotic factors and community descriptors using regression models. Results varied within size classes, but canopy openness was associated with changes in the community structure and diversity, and soil fertility did not affect species diversity. Tree density, basal area, and diversity were smaller in areas with more canopy gaps. Tree density and basal area increase with phosphorus availability, while the density of deciduous trees increased with canopy openness and base saturation. Thus, we found evidence that canopy openness and soil can explain small-scale variations of forest structure and diversity.

Resumo em Inglês:

ABSTRACT Eriotheca gracilipes concept is re-circumscribed according to the shape and texture of the leaflets, diameter of the petiole, calyx color, seed striation and geographic distribution. In addition, a new species (Eriotheca uniflora) and a new combination (Eriotheca crenulata) are proposed here. Descriptions, identification key, taxonomic comments, geographic distribution, phenology and conservation status, images of diagnostic characteristics and a table with information about these features are provided for the three species.

Resumo em Inglês:

ABSTRACT The long-term success of populations is dependent on individual reproductive success, and in general, increased population size and genetic diversity contribute to population maintenance, reducing the risk of local extinction. Interspecific hybridization has consequences that can vary according to the hybrids' fate, which can be strongly influenced by the reproductive capacity of hybrids and canonical individuals from the contact zone. We examined the reproductive biology and morphology of two closely related Petunia (Solanaceae) species and their interspecific hybrids from Serra do Sudeste, Southern Brazil, and we measured their reproductive success under controlled conditions based on seed production and germination from five pollination treatments. We found differences in self-compatibility degree among individuals, lineages, and pollination treatments based on high total seed production (> 204,000 seeds) and germination (630 seedlings evaluated). No correlation was observed between corolla colour and reproductive success or between floral morphological traits and compatibility. High self-compatibility and inter-lineage compatibility can explain the hybrid populations' maintenance and origin, favouring the two analysed species' introgression.

Resumo em Inglês:

ABSTRACT Paubrasilia echinata presents three morphotypes that differ from each other in leaf morphology (small morphotype-SM, medium morphotype-MM, and large morphotype-LM) with indications of divergence between them regarding irradiance tolerance. The present study aimed to identify possible physiological and growth patterns in P. echinata morphotypes under contrasting irradiance. The growth and photosynthesis of SM were inhibited in the full sun, and those of MM and LM, in the shade. The auxin contents of the three morphotypes increased in the full sun. However, in MM and LM, this increase was 5 times greater. The oxidative damage (hydrogen peroxide-H2O2 and lipid peroxidation-MDA content) of SM were higher in the full sun and of MM and LM in the shade. The stem hemicelluloses and CO2 assimilation decreased in shade for SM, and sun for MM and LM. The shade tolerance of SM and the full sun tolerance of MM and LM were associated with lower oxidative damage and cell wall loosening (lower hemicelluloses content) in the photo-promoted treatments. The integration of the lower oxidative damage with cell wall loosening seems to represent an essential part of the tolerance mechanism of P. echinata morphotypes in the shade and full sun.

Resumo em Inglês:

ABSTRACT One hypothesized invasion strategy (“try-harder”) predicts that invaders exhibit functional traits that are better adjusted to the environment than native species. Alternatively, the “join-the-locals” hypothesis predicts trait convergence between invasive and native species due to environmental filtering with increasing resource limitation. We hypothesized that invasions strategies shift from “try-harder” to “join-the-locals” with increasing elevation. We used an elevational gradient to detect possible trait convergences between alien invaders and native plant species in Asteraceae, Fabaceae and Poaceae. We found a significant trait convergence with elevation only in Asteraceae, suggesting a species-specific pattern, but also an important phenotypic variability of the alien invader. This supports the idea that the more resource-limited the environment, the more it filters out traits substantially diverging from the locally-adapted native community, thereby entailing a shift from “try-harder” to “join-the-locals” strategies. The invasive grass was also more acquisitive but did not exhibit any relation to the native community, supporting the “try-harder” hypothesis. The size of the invasive Fabaceae species decreased with elevation, mirroring the native Fabaceae species, but not the overall native community. Including more replicates and a thorough quantification of environmental conditions, offers a promising avenue for improving the understanding the seemingly idiosyncrasies of invasion pathways.

Resumo em Inglês:

ABSTRACT The digital era provides new opportunities for taxonomists, as well as for everyone that studies biodiversity. Many herbaria have been able to digitize their collections, a process that started with the typing of label data, moving more recently towards the digitization of each sample with the simultaneous acquisition of high-resolution images. Here we discuss some of the challenges we faced in digitizing samples and provide a series of suggestions to avoid common mistakes for herbaria that have yet to start the process. We used a professional camera, database management software, and a barcode scanner to digitize the collections of herbaria CRI, ECT, FURB, LUSC, and UFRN. Pre-revision of samples with prior restoration when needed, barcode fixation, and a good database allowed faster digitization of samples. Good database software and the formation of a network among small herbaria accelerated digitization and increased the number of images available of Brazilian biodiversity. Thus far, our joint efforts made 118,000 specimen images available online with the purpose of accelerating botanical research.

Resumo em Inglês:

ABSTRACT Understanding the role of photosynthesis in the holoparasitic genus Cuscuta may give insights into the biology and evolution of these plants. We hypothesised that light irradiance on the node of C. racemosa is important for sustaining the growth of the new shoot through photosynthesis. We blocked light irradiance on the node of detached twigs of C. racemosa for one week and measured twig fresh and dry weight, shoot length and photosynthetic pigment content. Even though fresh and dry weight did not differ between non-irradiated and irradiated twigs, the shoots of non-irradiated nodes were significantly shorter. The non-irradiated plants showed higher amounts of chlorophyll a, b, and lycopene, and a lower concentration of β-carotene. Furthermore, the chlorophyll a/b ratio was lower than that of the control (irradiated) plants. Beyond corroborating our hypothesis, our results suggest that, when light is blocked on the node of C. racemosa, the holoparasite responds in a way similar to that of autotrophic plants under shaded conditions. Our findings suggest a new and previously unacknowledged role for the node of C. racemosa, which would be supporting shoot elongation through photosynthesis.

Resumo em Inglês:

ABSTRACT Exotic palms are introduced as ornamental all over the world, with some of them become invasive. Here, we characterize the population status and the stage of invasion of the exotic palm Caryota urens in an Atlantic Forest Protected Area, southeastern Brazil. Palms were sampled in 2019 and 2020, in fifteen 10 x 10 m plots, placed from an alley of planted reproductive palms. All individuals inside plots were marked and classified in ontogenetic stages. The number of sampled individuals was 110 in 2019 and 114 in 2020; palms were recorded in six plots in 2019 (the furthest 330 m from the alley) and in eight plots in 2020 (the furthest 420 m from the alley). In 2020, most palms were on the earlier ontogenetic stages (seedlings and infants, 86 %), but we also recorded juveniles (10.5 %) and immatures (3.5 %), values similar to those found in 2019. The population structure observed and the natural expansion of the species inside the forest indicate that the palm has successfully established in the area and has become invasive. Management actions should be taken urgently in an attempt to contain the spreading to new locations or eradicate this palm from this protected area.

Resumo em Inglês:

Abstract Explosive pollination includes a rapid release of floral sexual elements that are enclosed in modified petals, and a subsequent contact with pollinators’ body. It requires specific groups of visitors in order to assure plant reproduction, thus reproductive success is threatened in species with explosive pollination mechanisms, especially when pollinator activity is uncertain. Autogamy can alleviate such a problem by improving plant reproductive output. Here we investigated the mating strategies of Marsypianthes chamaedrys, a species with an explosive pollen release mechanism and whose medicinal properties are broadly investigated, but no data is available regarding its reproduction. We studied its floral morphology, anthesis, floral visitors and breeding system. Flowers have a bilabiate organization with the reproductive structures housed within a lower, keel-like petal lobe. The species is protandrous and flowers have short life span. Only bees were able to activate the explosive mechanism, while butterflies acted as nectar thieves. Marsypianthes chamaedrys is self-compatible and able to autonomously self-pollinate, likely due to the elongation of the pistil within the keel of unvisited flowers. Marsypianthes chamaedrys likely has a mixed mating system, in which bee pollination and autogamy interplay to improve its reproductive output.

Resumo em Inglês:

ABSTRACT When foraging on a specific range of fruits or seeds, animals can represent a natural selection force, affecting plant population realized fecundity. Most studies have focused on characteristics of dispersed seeds, but the higher predation of seeds of specific size or shape is also an important force that influences the populations’ realized fecundity and can help to understand patterns of plants genetic variability. In the Brazilian Pantanal, we investigated the predation of Acuri (Attalea phalerata) palm fruits by macaws, whose seeds go intact through tapirs digestive tract and then are deposited on latrines, where they are often consumed by seed predators. We found 251 fruits, containing between 1 and 5 seeds per fruit; 170 were intact and 81 had been partially damaged by macaws, mostly those containing 3 or 4 seeds per fruit and with thin endocarps. We argue that the higher consumption of fruits with these traits reflects a trade-off in the energy spent by macaws to open the fruits and the energy provided by them. Higher predation on 3-4 seeded fruits favors the selection of 1-2 seeded fruits, revealing a selection force opposed to the one exerted by bruchids and small rodents, which favors multi-seeded palm fruits.