Diversity and Lability of Floral Phyllotaxis in the Pluricarpellate Families of Core Laurales (Gomortegaceae, Atherospermataceae, Siparunaceae, Monimiaceae)

Acacia (wattle) and Cananga (ylang-ylang): from spiral to whorled and irregular (chaotic) phyllotactic patterns – a pictorial report

“…Calycanthaceae as sister to all other Laurales, have spiral flowers consistently [9,44,45]. Irregular (chaotic) phyllotaxis, however, is found in the pluricarpellate female flowers of Monimiaceae (Laurales) with, e.g., Tambourissa ficus containing up to ca.…”

“…2000 carpels per flower [45]. While pointing to Tambourissa and other somewhat chaotic floral phyllotaxes in Laurales, Staedler and Endress [44] guessed: "These irregularities may be due to the fact that at the time of initiation, the floral apex is large in size compared to primordium size, and that organ identity would depend more on the immediate sectorial neighborhood than the position on the ontogenetic spiral in spiral flowers…". Their conclusion seems to fit also for Cananga (Fig.…”

Ancestral traits and specializations in the flowers of the basal grade of living angiosperms

“…There are three basic patterns of floral phyllotaxis to consider: (1) spiral, (2) simple whorled, and (3) complex whorled (Staedler & Endress, 2009). In simple whorls each whorl has the same number of organs, whereas in complex whorls the number increases from whorl to whorl by the intercalation of double positions, where two organs occur at the place where one organ would be expected in a simple whorled system, and may decrease again toward the floral centre.…”

Tracing the early evolutionary diversification of the angiosperm flower

“…With the data set of Endress and Doyle ( 2009 ), it was equivocal whether a spiral perianth originated once at the base of Laurales or more than once within the order, but with the changes in scoring of some taxa in Laurales by Doyle and Endress ( 2010 ), based on Staedler et al ( 2007 ) and Staedler and Endress ( 2009 ), it is now an unequivocal synapomorphy of the order ( Fig 4.1 A). Th is shift coincides with origin of a hypanthium (fl oral cup ), a conspicuous synapomorph y of Laurales.…”

“…An analysis by Sun et al ( 2002 ) identifi ed Archaefructus as the sister group of all living angiosperms , but the seed-plant analysis of Doyle ( 2008 ) placed it within the crown group, linked with the aquatic family Hydatellaceae , which were formerly considered highly reduced monocots, but have been recently shown to be basal Nymphaeales (Saarela et al, 2007 ). Th e most important changes in Doyle and Endress ( 2010 ) were re-scoring of androecial characters in Piperales in accordance with developmental data and interpretations of Liang andTucker ( 1995 ), Huff ord ( 1996 ) and Tucker and Douglas ( 1996 ), and the phylogenetic results of Wanke et al ( 2007 ); re-scoring of fl oral phyllotaxis and merism in some Laurales based on Staedler et al ( 2007 ) and Staedler and Endress ( 2009 ); and increasing the number of states recognized in the carpel number character.…”