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Disepalum comprises two monophyletic sister subgenera, Enicosanthellum and Disepalum, with strikingly different floral morphologies: the former has two whorls of unfused sepals, forming a partially enclosed floral chamber, whereas the latter possesses a single whorl of congenitally fused petals and lacks a floral chamber. The pollination ecologies of representative species are reported, including assessments of floral phenology, pollinators and floral thermogenesis. Disepalum pulchrum (subgenus Enicosanthellum) has hermaphroditic flowers with a pollination chamber and is protogynous with prolonged anthesis; it is pollinated by nitidulid beetles and drosophilid flies. Disepalum anomalum (subgenus Disepalum) is also hermaphroditic with prolonged anthesis, but has incomplete protogyny due to overlapping pistillate and staminate phases; it is pollinated by meliponine bees, which are attracted by the pollen, but which are only able to transfer pollen to receptive stigmas during the overlap phase. Alternative evolutionary hypotheses are evaluated, including the possibility that the ancestor of the subgenus Disepalum lineage may have experienced a profound genetic mutation, possibly involving genes responsible for organ merism and fusion, resulting in the loss of the pollination chamber and hence favouring different floral visitors. The breakdown in protogyny required for effective pollination is likely to have had significant ramifications on population genetic diversity. [ABSTRACT FROM AUTHOR]

Annonaceae flowers are generally hermaphroditic and show high levels of outcrossing, but unlike many other early-divergent angiosperms lack a self-incompatibility mechanism. We reassess the diversity of mechanisms that have evolved to avoid self-pollination in the family. Protogyny occurs in all hermaphroditic flowers in the family, preventing autogamy but not geitonogamy. Herkogamy is rare in Annonaceae and is likely to be less effective as beetles move randomly around the flowers in search of food and/or mates. Geitonogamy is largely avoided in Annonaceae by combining protogyny with floral synchrony, manifested as either pistillate/staminate-phase synchrony (in which pistillate-phase and staminate-phase flowers do not co-occur on an individual) or heterodichogamy (in which two phenologically distinct and reproductively isolated morphs coexist in populations). Unisexual flowers have evolved independently in several lineages, mostly as andromonoecy (possibly androdioecy). Functionally monoecious populations have evolved from andromonoecious ancestors through the loss of staminate function in structurally hermaphroditic flowers. This has been achieved in different ways, including incomplete pollen/stamen development and delayed anther dehiscence. Angiosperms display an enormous diversity of mechanisms to promote xenogamy, many of which are easily overlooked without fieldwork. Floral phenology is particularly important, especially cryptic differences in timing of organ maturation or abscission. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 174, 93-109. [ABSTRACT FROM AUTHOR]

Most angiosperms have gynoecia with two to five carpels. However, more than five carpels (here termed 'multicarpellate condition') are present in some representatives of all larger subclades of angiosperms. In such multicarpellate gynoecia, the carpels are in either one or more than one whorl (or series). I focus especially on gynoecia in which the carpels are in a single whorl (or series). In such multicarpellate syncarpous gynoecia, the closure in the centre of the gynoecium is imprecise as a result of slightly irregular development of the carpel flanks. Irregular bumps appear to stuff the remaining holes. In multicarpellate gynoecia, the centre of the remaining floral apex is not involved in carpel morphogenesis, so that this unspent part of the floral apex remains morphologically undifferentiated. It usually becomes enclosed within the gynoecium, but, in some cases, remains exposed and may or may not form simple excrescences. The area within the remaining floral apex is histologically characterized by a parenchyma of simple longitudinal cell rows. In highly multicarpellate gynoecia with the carpels in a whorl, the whorl tends to be deformed into an H-shaped or star-shaped structure by differential growth of the floral sectors, so that carpels become aligned in parallel rows, in which they face each other with the ventral sides. In this way, a fractionated compitum may still be functional. Multicarpellate gynoecia (with the carpels in one whorl or series) occur in at least one species in 37 of the 63 angiosperm orders. In contrast, non-multicarpellate gynoecia are present in at least one species of all 63 orders. The basal condition in angiosperms is more likely non-multicarpellate. Multicarpellate gynoecia are restricted to flowers that are not highly synorganized. In groups with synorganized androecium and gynoecium and in groups with elaborate monosymmetric flowers, multicarpellate gynoecia are lacking. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 174, 1-43. [ABSTRACT FROM AUTHOR]

In this article, a general description of the microscopic wood anatomy of Annonaceae is given. We provide a description of the wood anatomical features of the family and of all subfamilies and tribes, all from material in the Utrecht Wood collection. Hand-lens images can be an important help in identification, not only at the family level, but also at the level of genera or below, notwithstanding the fact that the number of characters that can be easily observed in end-grain photographs is restricted. The differences are often slight and difficult to summarize in a few words, making illustrations an indispensable tool. Therefore, we provide end-grain photographs of cross-sections of wood of 66 genera and > 90 species of Annonaceae. The variation seen in lens key characters is discussed against the framework of the current phylogenetic tree of the family. Additional remarks on microscopic features are given when appropriate. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 135-189. [ABSTRACT FROM AUTHOR]

The pollination biology of Annonaceae has received considerable attention, with data now available for > 45% of the genera (or genus-equivalent clades) included in recent molecular phylogenetic analyses. This provides a basis for understanding evolutionary shifts in the pollination system within the family. The present study focuses on subfamilies Anaxagoreoideae, Ambavioideae and Annonoideae, for which robust, well-resolved phylogenetic trees are available. Information is summarized on the pollination biology of individual clades and the evolutionary adaptations favouring different pollinator guilds evaluated. Although the majority of species of Annonaceae are pollinated by small beetles, five other pollinator groups are known: large beetles, thrips, flies, bees and cockroaches. Small-beetle pollination is inferred as the ancestral pollination system, with all other systems being derived. Evolutionary shifts to pollination by large beetles, thrips and flies are unlikely to have been significantly constrained by previous adaptations favouring pollination by small beetles, as many of the adaptations to these different pollinator guilds are similar (including protogyny, partially enclosed floral chambers and olfactory cues). In contrast, however, the evolutionary shift to bee pollination has presumably been constrained by both protogyny (as pollen-collecting bees are unlikely to visit pistillate-phase flowers) and the presence of floral chambers. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 222-244. [ABSTRACT FROM AUTHOR]

It is important that taxonomic knowledge is disseminated by those who possess it. This can be carried out via online databases, printed publications or training in taxonomic practice. For Annonaceae, the online database AnnonBase includes all published names of Annonaceae at any rank worldwide. Recently, an updated index to genera, species and infraspecific taxa of Neotropical Annonaceae was published in hard copy. This manuscript contains a concise update to the Bibliography of Annonaceae published by the late E. A. Mennega in 1993. Since his publication, much work has been carried out on systematics and evolution of Annonaceae, with the advent of molecular phylogenetics providing an additional stimulus. Here, however, we concentrate only on taxonomic papers focusing specifically on the description and circumscription of taxa (e.g. revisions, monographs, floras, checklists, descriptions of new species or phylogenetic studies that show monophyly/polyphyly/paraphyly of genera). The index should provide an easy entrance into the most important taxonomic literature on Annonaceae from 1900 onwards for the trained and untrained taxonomist with an interest in Annonaceae. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 41-73. [ABSTRACT FROM AUTHOR]

Many species of Annonaceae are known for their distinctive, penetrating floral aromas. Numerous pollination studies have documented floral scents which probably play a key role in specialized pollination strategies. In particular, floral scents appear to play crucial roles in deceptive pollination strategies, contributing to floral mimicry of ripe or decaying fruits, fungi and, potentially, carrion or faeces. Occasionally, floral scent may advertise genuine floral rewards, as is the case for two species of Unonopsis pollinated by male euglossine bees. To date, ten studies have chemically characterized floral scent for 24 species representing 11 genera of Annonaceae. In this review, I discuss the chemical composition and diversity of the analysed floral scents in Annonaceae. I also summarize and discuss a wide range of (human) perceptual descriptions of floral scent found throughout the literature on Annonaceae. I have framed discussions of floral scent in Annonaceae in ecological and evolutionary contexts whenever possible. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 262-279. [ABSTRACT FROM AUTHOR]

The pantropical flowering plant family Annonaceae is the most species-rich family of Magnoliales. Despite long-standing interest in the systematics of Annonaceae, no authoritative classification has yet been published in the light of recent molecular phylogenetic analyses. Here, using the largest, most representative, molecular dataset compiled on Annonaceae to date, we present, for the first time, a robust family-wide phylogenetic tree and subsequent classification. We used a supermatrix of up to eight plastid markers sequenced from 193 ingroup and seven outgroup species. Some of the relationships at lower taxonomic levels are poorly resolved, but deeper nodes generally receive high support. Annonaceae comprises four major clades, which are here given the taxonomic rank of subfamily. The description of Annonoideae is amended, and three new subfamilies are described: Anaxagoreoideae, Ambavioideae and Malmeoideae. In Annonoideae, seven tribes are recognized, one of which, Duguetieae, is described as new. In Malmeoideae, seven tribes are recognized, six of which are newly described: Dendrokingstonieae, Fenerivieae, Maasieae, Malmeeae, Monocarpieae and Piptostigmateae. This new subfamilial and tribal classification is discussed against the background of previous classifications and characters to recognize subfamilies are reviewed. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 5-40. [ABSTRACT FROM AUTHOR]

Identification keys are provided for all genera currently recognized in Annonaceae. Separate keys are presented for the Neotropics (34 genera), Africa-Madagascar (40 genera) and Asia-Australasia (42 genera). These keys are based on a combination of vegetative and fertile characters. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 74-83. [ABSTRACT FROM AUTHOR]

The 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. [ABSTRACT FROM AUTHOR]

Biologists are fascinated by species-rich groups and have attempted to discover the causes for their abundant diversification. Comprehension of the causes and mechanisms underpinning radiations and detection of their frequency will contribute greatly to the understanding of the evolutionary origin of biodiversity and its ecological structure. A dated and well-resolved phylogenetic tree of Annonaceae was used to study diversification patterns in the family in order to identify factors that drive speciation and the evolution of morphological (key) characters. It was found that, except for Goniothalamus, the largest genera in the family are not the result of radiations. Furthermore, the difference in species numbers between subfamilies Annonoideae (former long branch clade) and Malmeoideae (former short branch clade) cannot be attributed to significant differences in the diversification rate. Most of the speciation in Annonaceae is not distinguishable from a random branching process (i.e. chance), and no special explanations are therefore necessary for the distribution of species richness across the major part of the phylogenetic tree for Annonaceae. Only for a small number of clades can key innovations be invoked to explain the elevated rate of diversification. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 117-134. [ABSTRACT FROM AUTHOR]

The genus Dendrokingstonia (Annonaceae) is taxonomically revised and palynologically studied. Three species are recognized, one of which, D. gardneri, is described as new to science. One new combination, D. acuminata, is made. The genus occurs from southern Thailand to Peninsular Malaysia and Sumatra. On the basis of macromorphology and pollen characters, it is considered to be related to Monocarpia. Both genera show a combination of macromorphological characters that is rare in the family, i.e. considerably enlarged stigmas, leaves with percurrent tertiary veins, a highly reduced number of carpels per flower and relatively large monocarps with a thick, hard wall. Scanning and transmission electron microscopy show that the pollen grains of Dendrokingstonia and Monocarpia are monosulcate monads with a columellate infratectum and a more or less bulging intine at the sulcus. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 168, 76-90. [ABSTRACT FROM AUTHOR]