Download or read book Systematics and Phylogeny of Siphanthera Melastomataceae written by Frank Almeda and published by Amer Society of Plant Taxonomists. This book was released on 2011 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study represents the first attempt to evaluate generic and species limits in the South American genus Siphanthera by incorporating new information from macromorphology, pollen and seed micromorphology, chromosome cytology, a cladistic analysis, and distributional information. Available data provide a rationale for recognizing Siphanthera as a monophyletic genus of fifteen species with a bicentric distribution centered in the Brazilian Planalto, and the Guayana Highlands and contiguous areas. The monotypic genus Farringtonia has been merged with Siphanthera during this study and two new species are proposed here, S. todziae from the Amazon Basin and S. wurdackii from the Brazilian Planalto. The recent assignment of Siphanthera to the broadly defined tribe Melastomeae is called into question pending the results of a forthcoming family-wide multi-gene phylogenetic analysis. An evaluation of taxonomic characters used to recognize previous infrageneric groups has led to the abandonment of a formal sectional classification of the genus. Some major evolutionary trends in Siphanthera include: change from a perennial to an annual life cycle; change in foliar venation from basal acrodromous to loss of secondaries in one direction and change in the prominence of secondary veins and their pattern of divergence from the primary vein in another direction; reduction in inflorescence complexity from branched compound dichasia to congested capituliform inflorescences or few-flowered or solitary flowered inflorescences; change in petal shape from obovate with a rounded to acute base to more or less rotund petals with a clawed base; reduction in stamen number from eight fertile stamens to four fertile stamens; change in anther shape from elongate and subulate or rostrate with a small apical pore to ovoid or subrotund with a broad ventrally or dorsally inclined apical pore; and modification of capsule shape from essentially globose with a rounded apex to laterally compressed with a bilobed or notched apex. Species constituting the first diverging lineage in our cladogram suggest a possible Brazilian Planalto origin for the genus. Pathways to northward migration were opened via large areas of continuous savanna vegetation across the Amazon Basin that connected the Brazilian and Guayana Shields during climatic fluctuations of the Pleistocene. In a less likely alternative, the distribution of Siphanthera can be accounted for by vicariance of a widespread ancestor that spanned the Brazilian and Guayana Shields. In this scenario, the taxa that branch off from the first diverging clade in our phylogenetic tree could represent a geographic sequence of differentiation from the widespread ancestor and not a series of dispersal events. Present-day rain forest dominance of the Amazon Basin with its few and scattered savanna islands has largely isolated northern and southern populations of Siphanthera and appears to explain the prevailing bicentric concentration of species on the South American continent (publisher's description.
Download or read book Systematics Evolution and Ecology of Melastomataceae written by Renato Goldenberg and published by Springer Nature. This book was released on 2022-07-20 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a synthesis of critical new information for the Melastomataceae, one of the ten richest families among flowering plants with over 5,800 species that has its diversity highly concentrated in tropical or subtropical areas. It describes the family’s global diversity and distribution and summarizes recent advances in systematics, evolution, biogeography, reproductive biology and ecology.
Download or read book Neotropical Savannas and Seasonally Dry Forests written by R. Toby Pennington and published by CRC Press. This book was released on 2006-05-25 with total page 509 pages. Available in PDF, EPUB and Kindle. Book excerpt: More often than not, when people think of a neotropical forest, what comes to mind is a rain forest, rather than a dry forest. Just as typically, when they imagine a savanna, they visualize the African plains, rather than those dry woodlands and grasslands found in the Neotropics. These same preconceptions can be found among scientists, as these ne
Download or read book Memoirs of the New York Botanical Garden written by New York Botanical Garden and published by . This book was released on 1958 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Anther written by William G. D'Arcy and published by Cambridge University Press. This book was released on 1996-03-07 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher Description
Download or read book Atlas of Hairs for Neotropical Melastomataceae written by J. J. Wurdack and published by . This book was released on 1986 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: General considerantions. Comments on hair categories.
Download or read book Flowers on the Tree of Life written by Livia Wanntorp and published by Cambridge University Press. This book was released on 2011-09-22 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Genetic and molecular studies have recently come to dominate botanical research at the expense of more traditional morphological approaches. This broad introduction to modern flower systematics demonstrates the great potential that floral morphology has to complement molecular data in phylogenetic and evolutionary investigations. Contributions from experts in floral morphology and evolution take the reader through examples of how flowers have diversified in a large variety of lineages of extant and fossil flowering plants. They explore angiosperm origins and the early evolution of flowers and analyse the significance of morphological characters for phylogenetic reconstructions on the tree of life. The importance of integrating morphology into modern botanical research is highlighted through case studies exploring specific plant groups where morphological investigations are having a major impact. Examples include the clarification of phylogenetic relationships and understanding the significance and evolution of specific floral characters, such as pollination mechanisms and stamen and carpel numbers.
Download or read book Families and Genera of Spermatophytes Recognized by the Agricultural Research Service written by Charles R. Gunn and published by . This book was released on 1992 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paleocene Flora of the Rocky Mountains and Great Plains written by Roland Wilbur Brown and published by . This book was released on 1962 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of 170 kinds of plants and the strata that yield them, showing how they apply in the delimination of the Paleocene series.
Download or read book Fruits of the Guianan Flora written by Marc G. M. van Roosmalen and published by . This book was released on 1985 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology and Evolution of Flowers written by Lawrence D. Harder and published by Oxford University Press on Demand. This book was released on 2006-11-30 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: Floral biology, floral function, sexual systems, diversification.
Download or read book Seed Development and Germination written by Jaime Kigel and published by Routledge. This book was released on 2017-11-01 with total page 1045 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text is intended for plant physiologists, molecular biologists, biochemists, biotechnologists, geneticists, horticulturalists, agromnomists and botanists, and upper-level undergraduate and graduate students in these disciplines. It integrates advances in the diverse and rapidly-expanding field of seed science, from ecological and demographic aspects of seed production, dispersal and germination, to the molecular biology of seed development. The book offers a broad, multidisciplinary approach that covers both theoretical and applied knowledge.
Download or read book The Botany of the Guayana Highland written by Bassett Maguire and published by . This book was released on 1958 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Ecology of Neotropical Savannas written by Guillermo Sarmiento and published by Harvard University Press. This book was released on 1984 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrated view of the genesis of grasslands of the New World tropics, especially those of Venezuela.
Download or read book Essays in Evolution and Genetics in Honor of Theodosius Dobzhansky written by Max K. Hecht and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 601 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is not often that one has the opportunity to send a public birthday greet ing to a friend and colleague of many years, and to congratulate him on having reached the age of reason. In fact it happens only once, and comes then as a surprise. Surely it was only a few years ago that we sat together at an International Genetics Congress in Ithaca, and only yesterday that we became members of the same department. The eighth floor of Schermerhorn Hall had a north end where the flies were and a south end furnished with mice, and in between, a seminar room and laboratory. There the distances were short and the doors open and the coffee pot busy. But it now appears that yesterday has fallen thirty years behind and that we have grown up. I find it interesting and appropriate that Dobzhansky's lifetime spans the period of maturation of the fields to which this volume is devoted. This is true in a chronological sense for his birth occurred in the same year, 1900, in which modern genetics began. The rediscovery of Mendel's princi ples and the interpretation of the nature of heredity and variation to which this event led were necessary prerequisites to the development of evolution ary biology as presented in this collection of essays.
Download or read book Systematic Embryology of the Angiosperms written by Gwenda L. Davis and published by . This book was released on 1966 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:
