Cláudia Barbieri Ferreira Mendonça

Floral structure and palynology of Podostemum weddellianum (Podostemaceae: Malpighiales)

The family Podostemaceae is exceptional among angiosperms because of its uncommon biology and morphology, the absence of double fertilisation and endosperm, and the obscure distinction between root, stem, and leaf. The highly modified morphology produced by reductions and specialisations is reflected in the multiple positions that the Podostemaceae has occupied in different classification systems. In the family, structural studies are mainly related to the vegetative body. In the genus Podostemum, structural data are related to the development and embryology of Podostemumceratophyllum Michx., which, with P. weddellianum, has pre-anthesis cleistogamy. P. weddellianum is analysed for the first time with regard to floral structure and palynology. The presence of silica in the spathella, the apical septum in the ovary, dyads and pseudomonads, unimodal embryo sac and chasmogamous flowers with the possibility of self-pollination contribute to the characterisation of the Podostemoideae and the search for relationships among Podostemaceae and the clusioids.

Palynotaxonomy of Vernonanthura H. Rob. (Vernonieae, Asteraceae) species from Southeast Brazil

The present work studied the pollinic characteristics of 22 species of Vernonanthura from Southeast Brazil. The pollen grains were acetolysed, measured, described and ilustrated under light, scanning and transmission electron microscopy. Based on the results, Vernonanthura was considered an euripolinic genus as pollen grains presented distinctive characteristics, mainly related to the ornamentation, the size and apertures of the pollen grains, which may serve as a further tool in the delimitation of the species.

Pollen morphology and detailed sexine of Passiflora subgenus Astrophea (Passifloraceae)

From the palynological perspective, Passiflora subgen. Astrophea shows itself as a very interesting subgenus. The main aim of this study is to provide micro-characters that allow the recognition of taxa and the circumscription of the Passiflora subgen. Astrophea. The pollen was acetolyzed, measured, described and illustrated under light microscopy and non-acetolyzed pollen grains were analyzed in scanning electron microscopy. Quantitative data were subjected to multivariate analysis. The pollen grains are 6-colporate, 3-endoapertures clearly lalongate, unique for each pair of ectoaperture; tectate, partially tectate or semitectate exine, when present, muri may be only around the apertures or they may be remaining muri, continuous or discontinuous, simplicolumellate or duplicolumellate. The results defined four types of pollen, based on sexine, three of which were recognized by multivariate analysis. This study shows the importance of pollen morphology for the taxonomy of group, allowing a reassessment of the subgenus currently established and, hence, a better understanding of the recognized phylogenetic lineages.

Palinotaxonomia de espécies de Lepidaploa (Cass.) Cass. (Vernoniinae - Compositae) ocorrentes no Sudeste do Brasil

The pollinic study of 23 species of Lepidaploa that occur in southeastern Brazil was done with the objetive of contributing to the pollinic characterization of these species and also evaluating its taxonomic position. The pollen grains were acetolysed, measured, described and ilustrated under light microscopy. For further details of pollen surface and aperture, non acetolysed pollen grains were analysed by scanning electron microscopy (SEM) and, subsequently, electron-micrographed. Characteristics of pollen grains like shape, size and constitution of exine and aperture were studied. The pollen of the species analysed in this study varies from medium or large in size, isopolar, suboblate, oblate spheroidal or prolate spheroidal, subtriangular ambit, small or large polar area, 3-colporate with echinolophate surface. A key to identify the studied species was made based on pollinic data. Pollen grains from Lepidaploa have four main brochus organization pattern of the echinolophate exine. Three of these patterns can be divided into subtypes according to the apertural lacune shape.

The systematic value of pollen morphology in trees and shrubs species of Bauhinia L. (Caesalpinioideae- subg. Bauhinia - sect. Pauletia) occurring in Brazil

We analyzed the pollen grains of 30 taxa of the genus Bauhinia L., within five series: Aculeatae (9 species); Acuminatae (1 species); Cansenia (17 species); Pentandrae (2 species); and Perlebia (1 species). The pollen grains were acetolysed, after which they were photographed and analyzed under light microscopy. Non-acetolysed pollen grains were analyzed under scanning electronic microscopy. Characters such as shape, size, exine and aperture constitution were studied. The species were separated by a dichotomous key, which showed pollen grains that were classified as very large; isopolar or apolar; oblate, suboblate, oblate spheroidal or spherical; large or small in terms of the polar area; inaperturate, 3-porate or (3-7)-colpate; and microreticulate or reticulate, with or without supratectal elements (gemmae, bacula, clavae). The variation in pollen morphology confirms the eurypalynous status of the genus Bauhinia.

Palinologia de espécies de Gesneriaceae Rich. & Juss. ocorrentes no Estado do Rio de Janeiro, Brasil

This work deals with the study of pollen of 21 species from the family Gesneriaceae found in six genera, divided into three tribes: Beslerieae tribe - Besleria L. (4 spp.) Episcieae tribe - Codonanthe (Mart.) Hanst. (3 spp.) Nematanthus Schrad. (5 spp); Sinningieae tribe - Paliavana Vand. (1 sp.), Sinningia Nees (6 spp.) and Vanhouttea Lem. (2 spp.), occurring in Rio de Janeiro state, Brazil. We aim to characterize and expand the morphological data of the family, at the general or specific level, thus contributing to a more precise delimitation of taxa. The pollen grains were acetolysed, measured, described and illustrated using light microscopy. To see details of the surface and opening, non-acetolysed pollen grains were examined with a scanning electron microscope (SEM). The pollen grains of the species studied ranged from small to medium, suboblate to prolate; they had colpores or colpes and the number of openings was constant for all species (3-aperture). Ornamentation of the sexine ranged from scabrous to perforated, rugulate, microrreticulate and reticulated. The results showed that pollen morphology is well defined for the species studied; it varied within and between tribes and genera, can be used to identify taxa and maintains the eurypalynological character of the family Gesneriaceae.

Taxonomic significance of pollen morphology for species delimitation in Psidium (Myrtaceae)

Previous studies reported Psidium as one of the most difficult genera to delimit within the American Myrtaceae. Even though palynology has improved the taxonomy of Angiosperms, information about the usefulness of pollen morphology for taxonomic purposes in Myrtaceae remains contradictory. Here, we investigate the significance of pollen morphology for Psidium taxonomy with specific focus on its usefulness for determining species groups of taxonomic significance. Pollen traits observed by light and scanning electron microscopy were quantified and examined using cluster and ordination analyses. Average size of pollen grains was visualized by boxplots. Pollen grains of Psidium are isopolar, oblate, peroblate or oblate-spheroidal, 3-syncolporate or 4-syncolporate. The sexine ornamentation is rugulate, granulate or spinulose-granulate and differs between the mesocolpium and apocolpium. Cluster analysis revealed four distinct groups: Psidium cauliflorum (G1) and Psidium oligospermum (G3) as single-species groups; Psidium brownianum, P. oblongatum, P. ovale, P. sartorianum, P. guajava, Psidium sp. 1, Psidium sp. 2 (G2), and Psidium cattleianum, P. longipetiolatum, P. guineense, P. myrtoides (G4). Supported by ordination analysis, three traits better explained these groups: type of exine ornamentation, size of P-EV and pollen shape. The used approach efficiently distinguished related species, as well as explained species groups of taxonomic significance suggesting pollen morphology to be a significant source of information for taxonomic studies in Psidium.

Pollen morphology of the genus Eremanthus Less. (Vernonieae, Asteraceae)

In order to evaluate the significance of the pollen morphology for generic and infrageneric taxonomy of the genus Eremanthus (Vernonieae, Asteraceae), and to provide additional data for its phylogenetic reconstruction, the pollen of 20 of the 23 species of the genus was examined using light and scanning electron microscopy. Acetolysed pollen grains were measured, described, and illustrated using light microscopy, while non-acetolysed pollen grains were analyzed using scanning electron microscopy. Pollen grains of these species are isopolar, oblate-spheroidal in most of the species, more rarely prolate spheroidal or suboblate, subtriangular amb, tricolporate and subechinolophate. The variation among quantitative characters does not correlate with the macromorphological subdivision of the genus or with the generic or specific limits.

Estudo polínico em plantas de restinga do Estado do Rio de Janeiro - Clusiaceae Lindl.

This work deals with the palylonogy of eight species of Clusiaceae: Calophyllum brasiliense Cambess., Clusia criuva Cambess., C. hilariana Schltdl., C. lanceolata Cambess., C. parviflora (Sald.) Engl., Garcinia brasiliensis Mart., Kielmeyera membranacea Casar. e Symphonia globulifera L.f. The pollen material was acetolysed, measured, described and illustrated with photo or eletronmicrography (SEM). The main features of the pollen grains were studied: shape, size, exine constitution and aperture type. The pollen grains of Clusiaceae were small, medium or large in size, suboblate, oblate-spheroidal, prolate-spheroidal or subprolate, isopolar, porate (3-6) or 3-colporate, very small, small or large polar area, with rugulate or reticulate exine. It is concluded that the genera and the species can be separated by palynological characters, constituting an euripalynous group.

Pollen morphology of the genus Paralychnophora (Vernonieae–Asteraceae)

Paralychnophora is an exclusively Brazilian genus that has few species and a confusing taxonomy. The current study aims to help us better understand this genus by analysing pollen grains from six Paralychnophora species. The pollen grains were acetolysed, analysed and photomicrographed under light microscopy. They were not acetolysed for the scanning electron microscopy analysis. Features such as shape, size, exine constitution and aperture were investigated. The species were separated in a pollen key, and their features were of great diagnostic value for the genus. The ornamentation pattern allowed separating P. patriciana from P. reflexoauriculata, and it grouped the other taxa. P. atkinsiae distinguished itself by the polar area index (PAI) size. P. bicolor, P. harley and P. glaziouana were easily separated from each other when other features such as size, shape, distance between the spines and aperture dimensions were analysed together.