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The embryology, reproductive morphology, and systematics of Lecythidaceae

Posted on:1991-12-22Degree:Ph.DType:Dissertation
University:City University of New YorkCandidate:Tsou, Chih-HuaFull Text:PDF
GTID:1470390017950981Subject:Biology
Abstract/Summary:
Embryology prior to fertilization, palynology, and reproductive morphology are described at the generic level for the 20 genera of Lecythidaceae s.l.;These 20 genera are uniform in many embryological characters including: Basic-type anther wall formation, glandular tapetum of anther, bitegmic-tenuinucellate ovule, multi-cell-layered inner and outer integuments, Polygonum-type embryo sac formation, straight micropyle formed by inner integument only, and vasculatured outer integument. Embryological data suggest that the Lecythidaceae s.l. have greater similarities with the Theaceae, Ochnaceae, Scytopetalaceae, Ebenaceae, and Styracaceae than with other dicot families. However, good characters for resolving intrafamilial problems have not been discovered.;Palynology of the Lecythidaceae s.l. provides clearcut differences useful in separating the Planchonioideae as a monophyletic subfamily which is characterized by: syncolpate pollen with some specialized features, e.g., marginal ridges, marginal grooves, and polar cushions. The pollen of the other three subfamilies are of the common tricolpor(oid) at type without morphological autapomorphies and hence of no use in phylogenetic considerations.;The reproductive morphology of the 20 genera of Lecythidaceae s.l. exhibits a broad range of variation. The Lecythidaceae s.l. is considered as comprising a core group made up of the Planchonioideae and Lecythidoideae, and two problematic subfamilies, Foetidioideae and Napoleonaeoideae. The core-Lecythidaceae shares numerous characteristics in embryology, wood anatomy, and reproductive morphology with the Scytopetalaceae. On the other hand, the four genera of Foetidioideae and Napoleonaeoideae possess many specialized reproductive features, which suggests that they occupy positions more remote from the core-Lecythidaceae than the Scytopetalaceae does from the core-Lecythidaceae. Therefore, it is concluded that these four genera should not be included in a monophyletic Lecythidaceae consisting only of the Planchonioideae and Lecythidoideae.
Keywords/Search Tags:Lecythidaceae, Reproductive morphology, Genera
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