Structure and evolution of the androecium in the Malvatheca clade (Malvaceae s.l.) and implications for Malvaceae and Malvales
| Autor: | Heidrun Janka, William S. Alverson, Clemens Bayer, M. von Balthazar, David A. Baum, Jürg Schönenberger |
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| Rok vydání: | 2006 |
| Předmět: | |
| Zdroj: | Plant Systematics and Evolution. 260:171-197 |
| ISSN: | 1615-6110 0378-2697 |
| Popis: | Androecial development and structure as well as floral vasculature of six selected species of Bombacoideae and of several smaller lineages of the Malvatheca clade (Malvaceae s.l.) were studied. All studied taxa share a similar pattern of androecial development: initially, five antepetalous/antetepalous and five alternipetalous/alternitepalous primary androecial primordia develop on a ring wall. Two elongate secondary androecial primordia form on each antepetalous/antetepalous sector. At anthesis the androecium consists of an androecial tube crowned by five androecial lobes. Each of these lobes is the developmental product of an alternipetalous/alternitepalous primary androecial primordium and its two neighbouring antepetalous/antetepalous secondary androecial primordia. The elongate, sessile androecial units are positioned along the lateral margins of the androecial lobes and in the distal part of the androecial tube. Seen in the light of the most recent studies of floral development and phylogeny of the Malvaceae and the Malvales as a whole, our data indicate that i) elongate, sessile androecial units are ancestral in the Malvatheca clade, that ii) an obdiplostemonous floral ground plan is a synapomorphy for the Malvaceae, and that iii) diplostemony is most likely ancestral in the Malvales. |
| Databáze: | OpenAIRE |
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