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Author (up) Barabe, D.; Lacroix, C.; Gibernau, M.
Title Floral development of Urospatha: merosity and phylogeny in the Lasioideae (Araceae) Type Journal Article
Year 2011 Publication Plant Systematics and Evolution Abbreviated Journal Plant Syst. Evol.
Volume 296 Issue 1-2 Pages 41-50
Keywords Inflorescence; Homeosis; Angiosperms; Systematic; Morphogenetic constraints
Abstract In this paper we study merosity in the genus Urospatha within the framework of a resolved phylogeny of the Araceae. We analyse how a transition from dimerous or tetramerous merosity to pentamerous or hexamerous merosity can occur developmentally in the Lasioideae. In Urospatha, initiation of floral primordia along the inflorescence is acropetal, while development of flowers is basipetal. This indicates the presence of two distinct phases in the development of the Urospatha inflorescence. The first phase corresponds to initiation of flowers and establishment of the phyllotactic pattern, and the second phase to differentiation of floral organs. Urospatha is characterized by the presence of trimerous, tetramerous, pentamerous and rarely hexamerous flowers. In all types of flowers, the stamens are closely associated and opposite to the tepals. Pentamerous flowers are formed by addition of a sector comprising a stamen and tepal. Likewise, in the case of hexamerous flowers, two sectors are added. In the Lasioideae, the increase in the number of tepals and stamens is linked with two developmental processes that have appeared independently in the subfamily: (1) addition of one or two stamen-petal sectors (Anaphyllopsis and Urospatha), and (2) independent increase in the number of tepals and stamens on whorls, more or less organized and inserted in alternate position (Dracontium). Tetramerous whorls as they occur in basal Lasioideae would be homologous to two dimerous whorls from an evolutionary point of view.
Address [Barabe, D; Gibernau, M] CNRS UMR Ecol Forets Guyane 8172, F-97387 Kourou, France, Email: denis.barabe@umontreal.ca
Corporate Author Thesis
Publisher Springer Wien Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0378-2697 ISBN Medium
Area Expedition Conference
Notes WOS:000294201300004 Approved no
Call Number EcoFoG @ webmaster @ Serial 338
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