Floral structure and evolution in Ranunculanae
Apomorphic tendencies of unusual features shared by two or more families of the Ranunculanae are: early caducous sepals, congenitally closed gynoecium up to the level of the stigma (but still apically gaping after ovule initiation!), protruding diffuse pl
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Floral structure and evolution in Ranunculanae PETER K. ENDRESS Received September 11, 1994
Key words: Ranunculanae, M enispermaceae, Lardizabalaceae, Ranunculaceae, Berberidaceae, Papaveraceae. - Florai structure, fiarai evolution. Abstract: Apomorphic tendencies of unusual features shared by two or more families of the Ranunculanae are: early caducous sepaIs, congenitally closed gynoecium up to the level of the stigma (but stiIl apically gaping after ovuIe initiation!), protruding diffuse pIacentae, transverse fruit dehiscence (in Berberidaceae and Papaveraceae); excessive number of tepaI whorls (in some Menispermaceae and Berberidaceae); unisexuaI flowers, synandry, wet stigmas forming an externaI compitum (in Menispermaceae and Lardizabalaceae); eIaborate nectar-flowers, pollen with tricolpate-multiaperturate series, seeds with eIaiosomes (in some Ranunculaceae, Berberidaceae and Papaveraceae). Other unusuaI features shared by M enispermaceae and Lardizabalaceae may be plesiomorphic or apomorphic: non-peltate carpeIs, fleshy fruits. Thus, floral structure suggests close reIationships between Menispermaceae and Lardizabalaceae as weIl as Berberidaceae and Papaveraceae. A floral syndrome (probabIy myiophilous) consisting of small, flat, open, brownish or greenish flowers with short, spathuIate, often bilobed staminodes (petaIs) that present open nectar from their apex OCCurS in (more or Iess basaI) representatives of four famiIies (except for Papaveraceae). It may be plesiomorphic or represent a basaI apomorphic tendency in the
Ranunculanae.
The Ranunculanae (Ranunculiflorae) (DAHLGREN 1980, TAKHTAJAN 1987) are circumscribed here as comprising five families taken in a wide sense and induding some segregate families: M enispermaceae, Lardizabalaceae (ind. Sargentodoxaceae), Ranunculaceae (ind. Hydrastidaceae, Circaeasteraceae, Glaucidiaceae), Berberidaceae (ind. N andinaceae), and Papaveraceae (ind. Pteridophyllaceae, H ypecoaceae,
Fumariaceae).
Our knowledge on the five families is very unbalanced. While in Ranunculaceae, Berberidaceae and Papaveraceae floral structure and biology has been relatively well
studied, because they contain many temperate ornamental plants with attractive flowers, the largely tropical M enispermaceae with inconspicuous flowers is very poorly known. M enispermaceae and Lardizabalaceae are almost completely unknown concerning floral biology and floral development. In this survey, which also contains some new results, I am focusing on unusual characteristics, which are either synapomorphies or apomorphic tendencies U. Jensen et al. (eds.), Systematics and Evolution of the Ranunculiflorae © Springer-Verlag Wien 1995
P. K.
48 Menispermaceae
Lardizabalaceae
Ranunculaceae Berberidaceae
ENDRESS:
Papaveraceae
Floral organs never spiral, not even in polyandrous or polygynous flowers
Floral organs commonly in trimerous whorls, inc1uding gynoecium Floral organs spiral or irregular in polyandrous or polygynous flowers
Sepals early caducous Gynoecium congenitally c10sed up to stigma
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