Literaturbericht

A cornucopia of diversity—Ranunculales as a model lineage

“…Papaveraceae have caduceus (easily detached) sepals and nectarless petals in the Papaveroideae , and more or less persistent petaloid sepals and spurred and nectar-collecting petals in Fumarioideae ( Sauquet et al , 2015 ). In Berberidaceae and Ranunculaceae , flowers can also be perianthless or have a perianth differentiated into more or less caducous or petaloid and persistent sepals, and more or less modified and nectariferous petals traditionally referred to as ‘Nektarblätter’ ( Hiepko, 1965 ; Terabayashi, 1985 ; Endress, 1995 ).…”

“…Previous comparative studies have shown that Ranunculales petals can 2be more similar to sepals in position, development, structure, and function(s) (e.g. petaloidy), and thus referred to as petaloid sepals of bracteopetalous origin, or more similar to stamens called Nektarblätter or nectariferous staminodia of andropetalous origin ( Hiepko, 1965 ; Terabayashi, 1985 ; Endress, 1995 ). As in other eudicot lineages, the line between bracteo- and andropetals is usually defined by a set of developmental, structural, and functional traits which are thought to have evolved independently several times, including in the Ranunculales ( Ronse De Craene and Brockington, 2013 ).…”

“…Among the six families of Ranunculales that have flowers bearing a perianth ( Eupteleaceae are perianthless), such petaloid petals are observed in Menispermaceae , Circaeasteraceae , and in the subfamily Papaveroideae ( Papaveraceae ). In the other three families, the regular development of nectaries on the petals changes the shape, which becomes three dimensional due to the development of more or less pronounced nectar-storing invaginations ‘Nektarblätter’ ( Hiepko, 1965 ); they are considered as having an elaborate form compared with flat petals and have evolved several times in Ranunculales . The ancestor of Lardizabalaceae already had strongly reduced and nectariferous petals ( Zhang and Ren, 2011 ).…”