Thesis (M. Phil.)--University of Hong Kong, 2000. / Includes bibliographical references.

The principal objective of this investigation, was to collect the family Cyperaceae and to study their leaf, bract and culm anatomy. The second was to examine the collection for unique structures or forms, whilst a third was to classify the Cyperaceae according to their photosynthetic structures and types. Distribution of the Cyperaceae within the broad region defined as the Eastern Cape would be influenced by rainfall pattern. It was expected that C₃ species would predominate in more mesic environments and habitats, whilst the C₄ species would be found in drier less favourable habitats. Collection within the region (November 1993 to late January 1997), yielded 106 species, totalling some 600 specimens. Both sub-families of the Cyperaceae (Caricoideae and Cyperoideae), eight tribes (Abildgaardieae, Cariceae, Cypereae, Hypotvtreae, Rhynchosporeae, Shoeneae, Sirpeae and Slerieae) and twenty five genera were found to be present. Sixty percent of the species were C₃ and forty percent were C₄. Sixteen new species, which had not been collected within the boundaries of the region previously were also found. Over 43 percent of the species collected had unique anatomical characteristics that appeared to be influenced by habitat and or climate influenced. These are the characters influenced by hydromorphic, mesomorphic and xeromorphic environments. These anatomical characters: Thickness of leaves and bracts; thickness of the adaxial and abaxial epidermis of the leaves and bracts; flush, sunken and raised stomata; presence or absence of bulliform cells; presence and distribution of sclerenchymatous structures; presence or absence of a hypodermis; presence or absence of cavities in the leaves, bracts and culms; mesophyll or ground tissue structure, and the presence or absence of secretary structures. A few noteworthy anatomical characters that are influenced by climate are present in Cladium mariscus subsp. jamaicense (Schoeneae), the Cariceae, the Cypereae and the Sclerieae. Within Cladium mariscus subsp. jamaicense the pseudo-dorsiventral leaves and bracts, as well as the large lamina cavities, containing trans-lamina girders are unique. Papillate epidermal cells are limited to the tribe Cariceae. In the Cypereae many of the species lack bulliform cells and hypodermal layers. In Pycreus cooperi (Cypereae) the vascular bundles of the leaves and bracts, appear to be stacked in rows, that are inter-spaced with lamina cavities. In the Sclerieae the mesophyll structure is specific to the species level. Unique anatomical characteristics were also present in the leaves, bracts and culms of the genus Carpha. In this genus distinctive lateral vascular bundles were present abutting the large bundles and/or midrib bundle. The most distinctive anatomical characteristics that could be used to separate the members of the Cyperaceae were the structures and associated structures related to the photosynthetic pathway. The Eastern Cape Cyperaceae could be divided into three distinct groups based on photosynthetic structure, namely one C₃, a C₄ and a potential C₃-C₄ intermediate group. The C₃ group was found to have non-radiate mesophyll and an outer parenchymatous sheath with small chloroplasts (Cariceae, Cyperaceae [in part], Hypolytreae (Chrysithrix capensis], Rhynchosporeae [R. brownii], Schoeneae, Scirpeae and Sclerieae). The C₄ group has radiate mesophyll and an inner parenchymatous sheath with enlarged chloroplasts (Kranz or PCR sheath). The C₄ species are present in tribes Abildgaardieae, Cypereae (in part) and Rhynchosporeae (R. barrosiana). In the Eastern Cape, a few species with C₃ anatomy have anatomical characteristics that are similar to the species with C₄ anatomy (Cyathocoma hexandra [bracts], Cyperus tennellus var. tennellus [leaves and bracts], Ficinia bulbosa [leaves], F. dura [leaves and bracts], F. lateralis coastal [leaves and bracts], F. oligantha [bracts], F. pingiour [bracts], F. stolonifera [leaves and bracts], F. tribracteata [leaves and bracts], F. zeyheri [leaves and bracts], Isolepis cernua [leaves and bracts], I. costata var. macra [bracts], Schoenus nigricans [leaves], Scirpus nodosus [bracts] and Tetraria cuspidata [leaves and bracts)). The vascular bundles within this intermediate group, fall within the Hattersleyand Watson (1975) minimal cell lateral count and maximal cell distal count criteria for C₄ grass species. However, no biochemical data exists to see whether they are C₃-C₄ intermediates or whether the Hattersley and Watson (1975) C₄ criteria for grasses applies to smaller, or scutiform Cyperaceae or not. Based on the results presented here, five distinct structural forms/types were found to be present in the C₃, C₄ and C₃-C₄ intermediate groups. The C₃ and the potential C₃-C₄ intermediate species may be divided into two types, based on the number of vascular sheaths present. In the first or A-type, vascular bundles are surrounded by two sheaths and in the more dominant B-type, by three. The A-type was found in the Cypereae (Cyperus denudatus and C. textilis) and most of the Scirpeae. B-type anatomy occurred in the Cariceae, Cypereae (c. difformis, C. pulcher, C. sphaerospermus, C. tennellus var. tennellus and P. mundii), Hypolytreae, Rhynchosporeae (R. brownii), Schoeneae, Scirpeae (Bolboschoenus maritimus, Ficinia cinnamomea, F. fascicularis, F. lateralis both, F. pingiour, the genus Fuirena, I. diabolica, I. fluitans, I. prolifera and Schoenoplectus paludicola) and Sclerieae tribes. Based on the vascular sheath structure, the C₄ species could be divided into three groups, namely bulbostyloid, chlorocyperoid and fimbristyloid, where the bulbostyloid structure occurred in Bulbostylis schoenoides. Cyperus (in part), Kyllinga, Mariscus and Pycreus (except P. mundii) had a chlorocyperoid structure. Genera with fimbristyloid structure were recorded in the genera Abildgaardia, Bulbostylis and Fimbristylis. The bulbostyloid type represents a potential a fifth C₄ anatomical type within the C₄ Cyperaceae. As a result of this observation, it is possible that the C₄ syndrome may have evolved five times in the Cyperaceae and not four as previously suggested by Bruhl and Perry (1995) and by Soros and Dengler (2001). The C₃ Cyperaceae species within the Eastern Cape are more dominant in higher elevation habitats the C₄ species, similar to the C₃ grasses. The only C₄ species that occur at high elevations are those with three sheaths. The C₃ and C₄ species within the region occur in similar low rainfall habitat ranges, where the C₄'s are more dominant in xeric habitats on drier soils than the C₃ species, similar to the grasses. Where more C₃ species occur in higher rainfall habitats than the C₄ species. With the exception of the Afromontane Bulbostylis schoenoides and R. barrosiana, the C₄ species similar to the grasses are dominant in high light and temperature habitats with low rainfall, unlike the C₄ Cyperaceae of Japan and America. Only five species occur in the desert like conditions of the Karoo-Namib biome (Cyperus laevigatus, C. rupestris var. rupestris, I. cernua, M. capensis and M. uitenhagensis), which have less than 250mm of rainfall per annum. Only three species are habitat-specific or may be endemic to a specific area within the Eastern Cape, namely A. capensis, Chrysithrix capensis and R. barrosiana. A. capensis in marshes on the Amatole mountains near Alice and Hogsback. C. capensis to the Tstsikamma mountains of the Wite Els Bosch forests. R. barrosiana to the marshlands of the Cape Morgan coastal Nature reserve at Kei Mouth. The anatomical types of the C₃ and more especially C₄ Cyperaceae are not specifically found in a particular rainfall regime or habitat type, which is contrary to the thesis hypothesis. However, the C₃ species are mostly correlated with hydrophytic to mesic habitats, with the exception of Ficinia and the two sheathed species. Ficinia is dominant in mesic grasslands and halophytic habitats. The two sheathed C₃ species are mostly present in halophytic habitats. The C₄ species are also more dominant in mesic to xerophytic grasslands, as expected in the hypothesis. Where only a few species occur in habitats correlated with increasing rainfall and temperature similar to the C₄ Cyperaceae of Japan and America. It may thus be that the development and evolution of the different C₄ anatomical forms (or phylogenetic forms) within the Cyperaceae may have enabled these species to establish themselves in habitats that were alien to their origins. It may be that the ability to regulate photoassimilate and water transport within the Cyperaceae enables their success in a dynamic and unpredictable climate, such as the Eastern Cape. Many of the anatomical characteristics reported in this thesis and its appendices are unique to the tribes, genera and/or species of the Eastern Cape Cyperaceae and thus may be valuable to future taxonomic classifications of the family. The research presented here should provide a good working platform for future, more detailed research on this often forgotten component of the vegetation.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biologia Vegetal, Florianópolis, 2009. / Made available in DSpace on 2012-10-24T17:04:35Z (GMT). No. of bitstreams: 1 271050.pdf: 2092986 bytes, checksum: dfa540b78cd47d4b973ab23fcde00901 (MD5) / Androtrichum trigynum (Spr.) Pfeiffer é um gênero monotípico da família Cyperaceae ocorrendo em regiões litorâneas da costa sudoeste atlântica. Apresenta o sistema subterrâneo constituído por rizomas e raízes adventícias. Neste trabalho foram investigadas a ontogênese do sistema subterrâneo e análises quantitativas do rizoma, raízes e escapos florais de A. trigynum, coletados em dois ambientes da restinga do Parque Municipal das Dunas da Lagoa da Conceição em Florianópolis, caracterizados por dunas semifixas (DS) e baixadas úmidas (BU). Amostras do sistema subterrâneo e escapo foram coletados, fixados em FAA 70 e gluteraldeído 2,5% e processadas de acordo com as técnicas usuais em anatomia vegetal. O rizoma é espessado, plagiotrópico e simpodial, dele partem, escapos florais cuja base é coberta por catafilos, e as raízes. A partir do promeristema do rizoma diferencia-se a protoderme, o procâmbio e o meristema fundamental. Com o desenvolvimento, o meristema de espessamento primário (MEP) é observado entre a região cortical e o cilindro vascular. O MEP produz centrifugamente células parenquimáticas e centripetamente feixes vasculares anfivasais e células parenquimáticas. Posteriormente, a partir do MEP diferenciam-se a endoderme e o periciclo. Em secção longitudinal do ápice radicular são evidentes o caliptrogênio, que origina a coifa; o promeristema, o meristema fundamental, a protoderme e o procâmbio. Inicialmente a epiderme está constituída de células papilosas que secretam grande quantidade de substâncias entre estas e as células da coifa; a endoderme meristemática forma o córtex interno. Na maturidade parte do córtex interno desenvolve-se em aerênquima esquisolisígeno e as células corticais mais internas tornam-se espessadas. As células da endoderme são alongadas no sentido radial e apresentam paredes finas. O periciclo é plurisseriado. Muitos idioblastos contendo compostos fenólicos são encontrados no rizoma, raízes adventícias e escapos florais. Foram analisadas as seguintes características: diâmetro das raízes e rizoma; comprimento, diâmetro e área dos escapos florais; comprimento e diâmetro dos elementos de vaso das raízes, rizomas e escapos florais; grau de esclerofilia, densidade estomática, distância entre estômatos, comprimento total e parcial das células guarda e largura das células subsidiárias e espessura da cutícula e parede periclinal externa da epiderme do escapo floral, as médias foram comparadas por teste T de Student e estatística descritiva com o auxílio do programa Excel e BioEstat 5,0, porcentagens de similaridade e Análise de Similaridade foram usadas para contrastar a procedência e período de coleta e MDS foi empregado para mostrar a distribuição espacial das amostras. De maneira geral, os resultados indicam que a espécie apresentou maiores taxas de crescimento durante o verão, ou seja, no período mais úmido, mostrando-se adaptada ao ciclo hidrológico de alagamentos e drenagens das baixadas úmidas, ao resistir ao alagamento. Através do MDS, foi observada certa tendência à separação das características anatômicas em quatro grupos (BU inverno e verão e DS inverno e verão). A. trigynum apresentou características xeromorfas, embora elas ocorram em indivíduos de ambientes úmidos, provavelmente em conseqüência de pseudo xeromorfismo ou escleromorfismo oligotrófico, causado principalmente por falta de nutrientes no solo.

Made available in DSpace on 2014-06-11T19:32:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-23Bitstream added on 2014-06-13T19:21:41Z : No. of bitstreams: 1 silva_crm_dr_sjrp.pdf: 3743907 bytes, checksum: 69edb1e2123816de8a260fd606f4489c (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A família Cyperaceae é a terceira maior entre as monocotiledôneas, com 42 gêneros encontrados no Brasil. Eleocharis é o quarto gênero mais diverso, com 69 espécies encontradas em áreas alagadas, margens de rios e lagos. São plantas com morfologia simples, porém, com uma grande variação morfológica. Isto tem dificultado a identificação e organização taxonômica deste grupo. Este gênero, assim como toda a família, também é conhecido por possuir cromossomos holocêntricos, meiose pósreducional e formação de pseudomônades, além de uma grande variação intra- e interespecífica no número cromossômico. Buscando compreender a evolução cariotípica e esclarecer problemas taxonômicos neste grupo, foram estudadas 259 amostras de 10 estados brasileiros, representando cerca de 40% das espécies. Análises citogenéticas revelaram variação cromossômica interespecífica de 2n = 6 (E. subarticulata e E. maculosa) até 2n = 60 (E. laeviglumis), causada principalmente por poliploidia. Apesar desta variação, o número básico x = 5 é sugerido. As maiores variações intraespecíficas foram encontradas em E. maculosa (2n=10, 8, 7 e 6) decorrente de simploidia e no complexo de espécies formado por E. viridans e E. niederleinii, nas quais os dados citogenéticos e moleculares indicam uma origem híbrida associada à fissão e/ou fusão cromossômicas e poliploidia. A localização física dos sítios de DNAr 45S e 5S por FISH mostrou sinais de 45S sempre terminais e com múltiplos sítios (2 a 10). Esta multiplicação de sítios pode ser resultado de amplificação seguido de dispersão pelas pontas dos cromossomos com mesmo tamanho. O sítio de DNAr 5S foi menos variável em número (2 a 4) por cariótipos, contudo, variou entre as posições terminais e intersticiais. Este estudo mostra que os mecanismos responsáveis...

No description available.

A systematic study of two complexes of closely related species within Eleocharis subg. Limnochloa was conducted to better define poorly understood species and to lay the foundation for a worldwide revision of this group. Research utilized scanning electron microscopy (SEM), study of more than 2300 herbarium specimens and types from 35 herbaria, multivariate analysis, and field studies in the southeast United States and Mexico. Examination of achene gross- and micromorphology using SEM indicated a relationship among the species of the Eleocharis mutata complex (comprising E. mutata, E. spiralis, and E. cellulosa), their distinctness from the E. acutangula complex (comprising E. acutangula s.l. and E. obtusetrigona) and support the placement of all taxa studied within subg. Limnochloa. All species examined shared micromorphological characters typical of subg. Limnochloa. A systematic study of the worldwide morphological variation of E. mutata suggests it is represented by a single taxon throughout its distribution and is native to the New World and probably introduced in tropical Africa. The taxonomic relationship of Eleocharis mutata and E. spiralis was explored using discriminant analysis, PCA and phyto-geography, supporting the recognition of the two taxa as distinct at the rank of species. A systematic study of E. cellulosa suggests it is represented by a single taxon throughout its distribution, with an apparent Caribbean genotype distinguished by the presence of perianth bristles with retrorse spinules. A systematic study of the worldwide variation of E. acutangula s.l. resulted in its segregation into two infraspecific taxa, E. acutangula subsp. acutangula and E. acutangula subsp. breviseta, and two new South American species, E. neotropica and E. steinbachii. Nomenclatural history and lectotypification of certain taxa studied are discussed, and two basyionyms and two synonyms of accepted taxa are lectotypified. A taxonomic treatment is provided that includes a key, detailed descriptions and complete synonymy of each species, line drawings prepared from select specimens examined, and notes on habitat and distribution. Future research goals and needs are discussed.

A systematic study of two complexes of closely related species within Eleocharis subg. Limnochloa was conducted to better define poorly understood species and to lay the foundation for a worldwide revision of this group. Research utilized scanning electron microscopy (SEM), study of more than 2300 herbarium specimens and types from 35 herbaria, multivariate analysis, and field studies in the southeast United States and Mexico. Examination of achene gross- and micromorphology using SEM indicated a relationship among the species of the Eleocharis mutata complex (comprising E. mutata, E. spiralis, and E. cellulosa), their distinctness from the E. acutangula complex (comprising E. acutangula s.l. and E. obtusetrigona) and support the placement of all taxa studied within subg. Limnochloa. All species examined shared micromorphological characters typical of subg. Limnochloa. A systematic study of the worldwide morphological variation of E. mutata suggests it is represented by a single taxon throughout its distribution and is native to the New World and probably introduced in tropical Africa. The taxonomic relationship of Eleocharis mutata and E. spiralis was explored using discriminant analysis, PCA and phyto-geography, supporting the recognition of the two taxa as distinct at the rank of species. A systematic study of E. cellulosa suggests it is represented by a single taxon throughout its distribution, with an apparent Caribbean genotype distinguished by the presence of perianth bristles with retrorse spinules. A systematic study of the worldwide variation of E. acutangula s.l. resulted in its segregation into two infraspecific taxa, E. acutangula subsp. acutangula and E. acutangula subsp. breviseta, and two new South American species, E. neotropica and E. steinbachii. Nomenclatural history and lectotypification of certain taxa studied are discussed, and two basyionyms and two synonyms of accepted taxa are lectotypified. A taxonomic treatment is provided that includes a key, detailed descriptions and complete synonymy of each species, line drawings prepared from select specimens examined, and notes on habitat and distribution. Future research goals and needs are discussed.

Inaug.-Diss.--Tübingen. / Lebenslauf. Bibliography: p. 64-68.

The genus Scleria Bergius (Cyperaceae) in Southern Africa is critically examined, and the generic limits reviewed The taxonomic position of the genus in the family is examined. Diagnosis of the tribe Sclerieae is altered to circumscribe Scleria as the only genus, and diagnoses of the tribes Bisboeckelereae and Sclerieae are made. Infrageneric limits are re-assessed and two subgenera, Scleria and Hypoporum recognised, the relationship of which is postulated as co-lateral, not filial. Evidence is presented that ecological specialisation in subgenus Hypoporum has resulted in taxa which are adapted to open, seasonally dry, temperate habitats, whereas ecological specialisation in subgenus Scleria has given rise to taxa which are adapted to shady, wet, tropical and subtropical habitats. Taxa in subgenus Hypoporum are slender, usually narrow-leaved annuals, or perennials with annual aerial parts, that is, they have evolved drought/cold escape mechanisms, the annuals by completion of the life cycle in a season, the perennials by withdrawal of food reserves into a protected, subterranean perennating organ and sometimes also into enlarged culm-bases. Taxa in subgenus Scleria are more-or-less robust, usually broad-leaved perennials, or, less often, annuals. With few exceptions the plants are evergreen and do not manifest drought/cold escape mechanisms. The annual species occupy tropical habitats in areas where seasonal drought may be experienced and it is suggested that they have acquired the annual habit as a drought-escape mechanism. The only perennial species in subgenus Scleria in Southern Africa which has annual aerial parts, has evolved additional storage regioni in the swollen culm-bases. This species, S. transvaalensis occurs at higher, more temperate altitudes than other species in the subgenus. The fundamental branching pattern of the inflorescence of all species examined has been shown to be the same. It is postulated that the pattern is modified in two ways, namely, by progressive contraction of all or most ramuli leading to the "glomerate-spicate" type of inflorescence characteristic of subgenus Hypoporum, in which the bracts are reduced, glumiform structures, and, by progressive contraction of some ramuli and progressive elongation of others leading to the "interrupted-paniculate" type of inflorescence characteristic of subgenus Scleria, in which the bracts are foliaceous. It is suggested that the branched glomerate-spicate type of inflorescence is less specialised than the simply glomerate-spicate type, and that in the line with interrupted-paniculate inflorescences, the greater the degree of elongation and the greater the number of elongated ramuli, the more highly specialised the inflorescence. Evidence is put forward that the spikelet of Scleria is a monopodial, that is, racemosely-branched structure, and suggestions that it may be sympodial, refuted. It is postulated that unisexual spikelets in Scleria have been derived by reduction from bisexual (androgynaeceous) spikelets. Unisexual female spikelets are unknown in subgenus Hypoporum which has androgynaeceous spikelets and unisexual male spikelets. It is suggested that the higher the ratio of androgynaeceous to male spikelets in the inflorescence, the less specialised the inflorescence. Unisexual male and functionally unisexual female spikelets occur in subgenus Scleria and, rarely, androgynaeceous spikelets. It is suggested that species which consistently produce some androgynaeceous spikelets are more primitive than those which consistently lack them, and that species whose functionally female spikelets consistently lack any vestigial male parts are more advanced than those which have male rudiments. The hypogynium or "disc" which is present on some achenes is considered to be a new modification of the stipe of the achene and not a vestigial structure, therefore it is postulated that the type of achene found in subgenus Hypoporum which has a trigonous stipe lacking any distal elaboration as an hypogynium is primitive, and that the type of achene found in subgenus Scleria which has an obpyramidal stipe elaborated distally as an hypogynium is derivative. It is suggested that development of the hypogynium has attained its most specialised level in one group of species in which this structure serves as a flotation device. Diagnoses of sections in subgenus Scleria are based partly on differences in morphology of the hypogynium. It has been demonstrated that the cell-walls of the pericarp are silicified, that the process of silification is progressive proceeding from the apex towards the base of the fruit, and that abscission of the fruit takes place when silicification is complete and the vascular supply is severed. The achenes of subgenus Hypoporum have all cells silicified; those of subgenus Scleria have all cells except those of the free flange(s) of the hypogynium silicified. Scanning electron microscopy has revealed details of surface ornamentation of the achenes not previously known, which provide additional diagnostic characters at species level. Attemptsto germinate achenes of Scleria have been unsuccessful : the conditions required, physical and physiological, are not understood. Analysis of anatomical evidence, in particular those characters seen in transverse sections of laminas and culms, confirms that there has been specialisation along two divergent pathways; one which has led to successful occupation of relatively dry, temperate habitats (subgenus Hypoporum), and the other to successful occupation of shaded damp, and open aquatic, subtropical and tropical habitats (subgenus Scleria). One section, Hypoporum, is recognised in subgenus Hypoporum, pending survey of the subgenus on a world basis. Four sections are recognised in subgenus Scleria, namely, Scleria, Acriulus, Schizolepis and Ophryoscleria. Section Scleria may comprise several natural groups, the delimitations of which can not be attempted until a world survey has been made. A map showing world distribution of the genus, and regional distribution maps of Southern African species are provided, also a Table showing the total distribution range of species recorded from Southern Africa. Generic, subgeneric, sectional and species descriptions are provided. Two new species are described. Keys to the Southern African species for use in the herbarium, in the field, and one based on anatomical characters of the laminas are presented. Original descriptions and photographs of type specimens of taxa represented in Southern Africa are included as appendices. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1983.

Thesis (Ph. D.)--Washington State University, December 2007. / Includes bibliographical references.