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Previously published descriptions of the pollen morphology of the Palmae are reviewed and discussed. The earliest macro fossil records for palms are summarised, while a more detailed review is given of the fossil records of palmlike pollen. Selected literature relating to pollen sharing some similarities to palm pollen in other monocotyledonous families are briefly reviewed, and the fossil pollen records for these families are examined. A brief chronological account of earlier systematic treatments of the palms is provided, as well as an outline of the systematic treatment of the family used in the present account. The pollen morphology of 1150 collections, representing 765 species of palms,f rom all but seveno f the currentlyr ecognisedg enera,h asb eene xamýined, as well as dispersedp alm-likef ossil pollen from the middle Eoceneo f the Isle of Wight, and of Java. Iii silit pollen of fossil palm flowers from the Messel oil shales (Germany)a re describedP. ost meiotic tetrad stageh asb eens tudiedf or representatives peciesin all subfamiliese xceptingt he PhytelephantoideaeP.o llen morphologyo f both recenta nd fossil pollen is describedf rom light, scanning electrona nd, selectivelyf rom transmissione lectronm icroscopy,w hile tetrad resultsa re from light and scanninge lectronm icroscopy.F ull detailso f preparation methods,t erminologya nd databaseus sedf or pollen morphological,f ossil and tetrad studies are given. Seventeena perturet ypes,p lus numerouss ubtypesa, nd twelve exine types with numerous subtypes are identified. The aperture types are shown to be broadly separablein to two groupsw hich are associatedw ith either simultaneous (tetrahedralt etrads)o r successive(t etragonalt etrads)m icros porogenessi. In generalt heset wo groups supportp resents ystematico pinion regardingt he subfamilies.S uccessivem eiosisi s dominanti n subfamiliesC alamoideaea nd Nypoideaew hile, with somer are exceptionss, imultaneousm eiosisp redominates in the remainingf our subfamiliesC: oryphoideaeC, eroxyloideaeA, recoideaea nd PhytelephantoideaeP.o llenu ltrastructurei s treatedi n detail only for simple tectate exines where it is important for further definition. Six types and a number of subtypesa re described.T he systematicd istributionso f aperturea nd exine types are summarisedA. trend towardsl arger pollen is noted, with the smallest pollen occurring in the least specialised subfamily, the Coryphoideae, while very large-sized pollen are characteristic of subfamily Phytelephantoideae. Monosulcate, disulcate and zonosulcate pollen are described from fossil material and closest affinities with recent palms suggested. Pollen morphology of recent palms is summarised and discussed, and compared with pollen of selected monocotyledonous families. The bearing of pollen data on recent palm systematics is considered at various levels from subfamily to species. Angiosperm pollen evolution is re-considered and evolutionary pathways for palm pollen aperture types and exine types are suggested. In the light of recent pollen morphology for the family the fossil record of palm pollen is re-evaluated. Some widely accepted affinities are challenged while previously unconsidered affinities are suggested, particularly for the mid- Cretaceous. The need is emphasized for future fossil pollen studies to look critically for pre Late Cretaceous palm-like monosulcates, which would be more informative of the early history of the family than the apparently highly evolved, easily recognisable Spini. -onocolpiles of the Late Cretaceous. Palaeogeography, environment and distribution of fossil records and depositional environment are discussed. Probable evolutionary pathways of pollen morphology, including pollen tetrad data which suggests imultaneousra thert han successivem eiosisa s the plesiomorphics tate,o ffer further evidencet hat the palmsa re indeeda n ancient group, and support the hypothesis that the palms may have originated in South America and Africa (West Gondwana)in the Late Jurassic or early Cretaceous, prior to the complete separation of these continents.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2015. / External pollen grain morphology has been widely used in the taxonomy and systematics of flowering plants. The eurypalynous family Acanthaceae is a notable example of a group where these pollen diversities have proved useful in determining relationships between taxa. However, internal pollen wall features have received far less attention due to the difficulty of examining the underlying exine from which the external sculpturing is derived. Consequently, internal wall features have thus far not been used in formulating existing classifications. A new technique involving precise cross sectioning or slicing of pollen grains at a selected position, using a focused ion beam-scanning electron microscope (FIB-SEM), was used on 39 species of Acanthaceae to examine the internal pollen wall structure and identify features of potential systematic relevance. Five basic internal wall structures were described in this study. The study also showed that similar external pollen wall features may have distinctly different underlying structures.

Call number: LD2668 .T4 1978 Z44 / Master of Science

Orientador: Eduardo Custódio Gasparino / Coorientador: Alain Chautems / Banca: Cynthia Fernandes Pinto da Luz / Banca: Claudia Barbieri Ferreira Mendonça / Resumo: Palinotaxonomia em Espécies Brasileiras do complexo Codonanthe- Codonanthopsis (Gesneriaceae) e gêneros relacionados - Será estudada a morfologia dos grãos de pólen de 25 espécies brasileiras dos gêneros Codonanthe (Mart.) Hanst., Codonanthopsis Mansf., Nematanthus Schrad. e Paradrymonia Hanst., distribuídas em sua maioria em dois biomas, Amazônia e Mata Atlântica. O objetivo deste trabalho é contribuir com a caracterização palinológica, em busca de dados morfológicos que possam melhor definir as espécies estudadas, auxiliando dessa forma, o melhor entendimento das relações de parentesco entre os gêneros e na compreensão da distinção florística entre os respectivos biomas. Os grãos de pólen foram acetolisados, medidos e fotografados sob microscopia de luz, microscopia eletrônica de varredura e transmissão. Os dados quantitativos receberam tratamento estatístico e descritivos, adequado ao tamanho das amostras e foram submetidos a uma análise multivariada identificando caracteres polínicos importantes na distinção das espécies. Os resultados obtidos com este estudo confirma a diversidade polínica para a Gesneriaceae, como já relatado na literatura. Os caracteres que mais contribuíram para distinção entre os gêneros, que auxiliarão trabalhos evolutivos futuros, foram a ornamentação dos grãos de pólen e as características de abertura. As espécies de Codonanthe e Codonanthopsis apresentam ornamentação predominantemente microrreticulada, diferente de Paradrymonia e Nematanthus com ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Palynotaxonomy in Brazilian species of Codonanthe-Codonanthopsis complex (Gesneriaceae) and related genera - The morphology of the pollen grains of 25 Brazilian species Codonanthe (Mart.) Hanst., Codonanthopsis Mansf., Nematanthus Schrad. and Paradrymonia Hanst., distributed mostly in two biomes, the Amazon rainforest and Atlantic Forest. The objective of this study is to contribute with the palynological characterization, in search of morphological data that can better define the studied species, a, thus helping, the better understanding of kinship relations between the genera and in the understanding of the floristic distinction between the respective biomes. The pollen grains were acetolysed, measured and photographed under light microscopy, scanning electron microscopy and transmission. The quantitative data were submitted to a multivariate analysis, identifying pollen characters that were important for the species classification. The results obtained with this study confirm the pollen diversity for the Gesneriaceae, as already reported in the literature. The characters that contributed the most to distinguish between the genera, which will help future evolutionary works, were the ornamentation of the pollen grains and the aperture characteristics. The species of Codonanthe and Codonanthopsis present predominantly microreticulate ornamentation, different from Paradrymonia and Nematanthus with pollen grains mostly reticulate. For Paradrymonia, there were no variations in the ornamentation of the apocolpium and mesocolpium of its pollen grains; in Nematanthus we can see a variation in the pattern of ornamentation between the apocolpium and mesocolpium regions (from microreticulate, reticulate to foveolate). Pollen grains with colpate aperture were described for Codonanthopsis, and for Paradrymonia pollen grains colp... (Complete abstract click electronic access below) / Mestre

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Pollen morphology of 8 species (TEM), 86 species (SEM), and leaf anatomy of 62 species (LM), were surveyed in the Oisinae, Coryclinae and, as outgroup taxa, the Orchideae and Satyriinae. Characters extracted from observations made of leaf anatomy and pollen were analysed using cladistic methods, and assessed in relation to the present phylogeny of the group. Leaf anatomy data gave little phylogenetic information. Sclerification associated with vascular bundles was systematically useful. Pollen data served to resolve taxa at the subtribal level. Both data sets provided evidence of relationship for taxonomically problematic taxa. The Coryciinae are palynologically defined by a suite of synapomorphies, including a secondarily tectate exine structure, fasciculate massulae, and elongated tetrads with linear microspore configuration. Bibliography: pages 107-123.

Increasing the taxonomic resolution of fossil pollen identification is important for accurate paleoecological reconstructions. Here, an attempt is made to identify the critical morphological features that will permit differentiation of Alnus pollen in fossil records. Palynologists working in the Pacific Northwest often distinguish alder pollen into two morphotypes. However, no definitive method outlining the validity of species level identifications has been devised to date. To test and validate species-level identifications, the pollen morphology of the three main alder species (Alnus viridis subsp. sinuata, Alnus incana subsp. tenuifolia and Alnus rubra) that occur in westernNorth America is examined with the goal of identifying morphological characteristics with which to distinguish the pollen of these species in fossil records. Modern pollen samples were collected from 27-35 individual plants from across the range of each of the three alder species. Pollen grains (n=30) from each individual plant were examined using light microscopy at 1000´ magnification under oil immersion. For each individual pollen grain, six quantitative traits (pollen grain diameter, exine thickness, arci width, and annulus height, width and area), and three qualitative traits (pore protrusion, grain shape and arci strength) were measured. In total, 21,390 alder pollen were examined from 93 separate collections. In addition, the number of pores was determined for 200 pollen grains from each individual plant. Statistically significant differences between species were found for all quantitative traits when traits were compared via nested ANOVA. However, there is high variability in pollen morphology within each species and pollen morphology is best described as occurring along a morphological continuum. A single morphological trait is insufficient for precise identification of alder pollen to species. CART analysis, when used to derive a multi-trait classification model, is shown to be a useful tool in separating the pollen of A. rubra and A. viridis subsp. sinuata into two separate ‘morphotypes,’ analogous to species identification. The confounding intermediate morphology of A. incana subsp. tenuifolia precludes the possibility of distinguishing the pollen of all three species. CART modelling isolates A. rubra and A. viridis subsp. sinuata pollen based on annulus width, arci strength, diameter and exine thickness, traits that support the differences used by palynologists for separating alder pollen into ‘morphotypes.’ Sensitivity analysis shows clearly that the common practice of using small sample sizes (e.g. n=7 and n=15) for identifying critical morphological traits for pollen identification produces misleading and erroneous results. Regional differences in pollen morphology were also assessed by splitting the dataset into regions. Classification accuracy is diminished from over 70% to less than 20% when a CART model derived from pollen grains from one region is used to classify grains from a different region. This research underscores the importance of using large sample sizes from across species’ ranges when attempting to determine the diagnostic morphological features for accurate pollen identification. / Graduate

Ephedra (Gnetales) is a gymnosperm genus with a long evolutionary history; the first dispersed pollen grains with affinity to the group are known already from the Permian. This thesis focuses on the evolutionary history of the group and different aspects of its pollination mechanisms. Despite the limited number of extant species of the genus (50-60), and a low morphological and genetic divergence among species, there is variation in pollination syndrome in the genus. The prevailing state in Ephedra, and most gymnosperms, is wind pollination. It is therefore surprising that one species, E. foeminea, is insect-pollinated. Together with co-workers I documented the pollination syndromes of E. foeminea and a sympatric species, E. distachya, based on long term field experiments in north-eastern Greece and aerodynamic investigations and calculations. Placing the results into an evolutionary framework reveals that the insect-pollinated species E. foeminea is sister to the remaining (mostly wind-pollinated) genus, and indicates that insect pollination is the ancestral state in the Gnetales. During the course of evolution of the group there has been a shift to wind pollination, which may have played a crucial role for the diversification of the crown group in the Paleogene. Pollination biology is often correlated with the morphology of the pollen such that pollen grains of anemophilous plants are small with a smooth surface, whereas pollen grains of entomophilous plants are larger with an ornamented surface and a covering of pollenkitt. The pollen morphology of Ephedra can be broadly divided into two types: an ancestral type with an unbranched pseudosulcus between each pair of plicae, and a derived type with a branched pseudosulcus between each pair of plicae. Further, the pollen morphology and ultrastructure of the pollen wall in Ephedra are to some degree correlated with the pollination syndrome and capability of long distance dispersal. Pollen of E. foeminea has a denser ultrastructure, as a result a higher settling velocity and is therefore capable of flying shorter distances than does pollen of the anemophilous E. distachya, and other investigated anemophilous species that show a more spacious ultrastructure of the pollen grain. These results can be useful in the reconstruction of the pollination mechanism of extinct taxa of the Ephedra-lineage in the future.