01975nas a2200229   4500008004100000020001400041245006800055210006800123260002900191300001200220490000800232520131600240653001601556653001601572653001501588653001501603653001401618653001601632100002001648700002201668856005501690       2012                        eng d  a1095-833900aEvolution and phylogenetic significance of pollen in Annonaceae0 aEvolution and phylogenetic significance of pollen in Annonaceae  bBlackwell Publishing Ltd  a190-2210 v1693 aThe remarkable diversity of pollen morphology in Annonaceae has attracted systematic attention since the 1970s. Optimization of pollen characters on a molecular tree confirms that granular monosulcate pollen, as in Anaxagorea and subfamily Ambavioideae, was ancestral in the family. However, granular structure is derived for angiosperms as a whole, and exine characters are highly homoplastic in Annonaceae. Because columellar taxa (Annickia, Bocageeae) diverged earlier than previously thought, columellae may have re-originated in the common ancestor of Malmeoideae and Annonoideae, which make up most of the family, with several later reversals to granular structure. In Malmeoideae, loss of the sulcus and origin of a verrucate tectum occurred in the tribe Miliuseae, followed by an uncertain number of origins of disulculate pollen. Tetrads arose several times in Annonoideae, but reverted to monads in Isolona and probably Uvarieae. Recognition that microspores rotate during development in Annona and Cymbopetalum suggests that the proximal thin area in these taxa is a modified distal sulcus, but rotation does not occur in all tetrad groups; a broader survey is needed to evaluate this phenomenon. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 190–221.10aangiosperms10aMagnoliales10amorphology10apalynology10aphylogeny10aSYSTEMATICS1 aDoyle, James, A1 aLe Thomas, Annick  uhttp://dx.doi.org/10.1111/j.1095-8339.2012.01241.x02121nas a2200253   4500008004100000020001400041245006900055210006800124260002900192300001100221490000800232520140000240653002001640653001001660653002301670653001601693653002101709653001401730653000801744653001801752100002201770700002001792856005501812       2012                        eng d  a1095-833900aDating clades with fossils and molecules: the case of Annonaceae0 aDating clades with fossils and molecules the case of Annonaceae  bBlackwell Publishing Ltd  a84-1160 v1693 aThis article addresses the challenges involved in estimating the ages of clades using fossils and DNA sequences. We review the principles and problems of placing fossils in trees of extant taxa and using them to constrain the ages of nodes in molecular dating analyses. Endressinia and Futabanthus provide minimum ages of 112 Mya for the stem lineage and 89 Mya for the crown group of Annonaceae, and the diversity of endosperm ruminations in seeds from the London Clay indicates that the four main clades of Annonaceae had diverged by 50 Mya. Ages inferred using these minimum constraints and a plastid phylogenetic tree for Annonaceae, particularly crown ages of the two main clades (Malmeoideae and Annonoideae), depend on assumptions regarding the pattern of variation in rates of molecular evolution. Our results using methods that assume rate autocorrelation or log-normal distribution of rates suggest that neither assumption fits well the apparently abrupt changes in rates in Annonaceae. Instead of soft-bounded age constraints, we argue for the use of only well-substantiated fossil evidence by means of priors with hard bounds. Thus, we can infer ages that take into account both palaeontological and phylogenetic uncertainty, without confounding the different factors involved. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 84–116.10aage constraints10aBEAST10afossil calibration10aMagnoliales10amolecular dating10aphylogeny10ar8s10arelaxed clock1 aPirie, Michael, D1 aDoyle, James, A  uhttp://dx.doi.org/10.1111/j.1095-8339.2012.01234.x