Search

The evolution of the tropical lowland forests in northern South America is poorly understood, yet new insights into past composition and changes through time can be obtained from the rich and diverse fossil pollen record. Here we present a revision of two diagnostic Malvaceae taxa from the Cenozoic record of northern South America and we relate their evolutionary history to recently updated geological models. In our study we review the pollen morphology and botanical affinity of Rhoipites guianensis and Malvacipolloides maristellae, and integrate these data into a phylogenetic framework. We also produce distribution maps for both fossil and extant taxa, infer the phylogeny and historical biogeography of the lineages to which they belong, and identify their ecological associates and environmental settings. The closest extant relatives of Rhoipites guianensis (Grewioideae) are Vasivaea and Trichospermum, which are taxa of South American origin. During the late Eocene to early Miocene Rhoipites guianensis was widely distributed in the lowland floodplain environments of northern South America. The closest living relatives of Malvacipolloides maristellae (Malvoideae) are members of Abutilinae (e.g., Abutilon, Bakeridesia, Callianthe and Herissantia), which have their origin in the northern hemisphere. This taxon makes its first appearance in the fossil record of northern South America during the early Miocene, and is typically found in fresh water floodplain and lacustrine environments. Our study suggests that both taxa migrated across the Central American Seaway in the early Miocene (around 18 Ma), and virtually disappeared from the fossil record in northern South America during the middle Miocene, coinciding with Andean uplift. However, their descendants expanded and -in the case of the Abutilinae—diversified in the Andes. We conclude that the biogeographic history of these Malvaceae is influenced by Andean uplift and the incipient bridging of the Americas. Thereafter, climate change and diversification of the Andean landscape enabled their descendants to move upslope and into the Andes.

The pollen of Trigonostemon and the related genera Dimorphocalyx, Ostodes, Tritaxis and Jatropha (outgroup) has been studied with light microscopy, and scanning and transmission electron microscopy. The two major pollen types within Trigonostemon correlate well with macromorphological characters. Species belonging to the Trigonostemon reidioides type have pollen with ‘croton pattern’ ornamentation, a pistil with deeply divided stigmas (to at least half the length of the stigma arm) and stamens with a protruding appendage on the connective, while species of the Trigonostemon verrucosus type have verrucate (to almost gemmate) pollen, stigmas that are shortly cleft and stamens without an appendage on the connective. Dimorphocalyx, Ostodes, Tritaxis and Jatropha (outgroup) have similar pollen morphology, while Trigonostemon deviates from these genera in the absence of the ‘vertically’ striate ornamentation on the subunits. Therefore, when compared with an existing phylogeny of the Euphorbiaceae, the pollen characters of Trigonostemon appear to be derived. Moreover, because the ‘croton pattern’ ornamentation itself is widely shared by the ‘inaperturate crotonoids’, the loss of that structure in the Trigonostemon verrucosus type pollen is considered a further apomorphy.

A new species of saleniid is recorded from the so-called ‘Eagle Ford Condensed Zone’ with typical elements of the late Turonian Prionocyclus hyatti cephalopod Zone, which rests unconformably on the South Bosque Marl ( Collignoniceras woollgari cephalopod Zone) in the Georgetown area, Williamson County (central Texas). It is easily distinguished from both extinct (late Albian–early Paleocene) and extant congeners by a comparatively low test, wide ambulacral zones with large (near-)horizontal pore pairs, a large peristome with conspicuous gill slits and a highly ornamented apical disc with a relatively small suranal plate. The new species constitutes the first record of the genus Bathysalenia from North America.

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.

Dichotomously branched stem fragments with crowded, spirally arranged, trifurcate leaf base remains from the type area of the Maastrichtian (Late Cretaceous; SE Netherlands, NE Belgium) are described as a new genus and species: Mosacaulis spinifer Van der Ham et Van Konijnenburg-van Cittert. They are interpreted as fossils of (pseudo)herbaceous axes with densely spaced, semi-amplexicaul leaves arranged in low spirals, with reproductive structures (sporangia?, prophylls associated with flowering axes?) attached to the adaxial sides of the leaf bases. M. spinifer is considered to be of unknown affinity (incertae sedis), showing resemblances with such disparate lineages as lycopsids and angiosperms. Its seagrass-like habit, gregarious occurrence, the association with genuine seagrass and a diverse marine fauna (including epibionts on the stems), and the absence of any terrigenous material, remains of land plants and terrestrial palynomorphs suggest that M. spinifer grew in a fully marine environment.

The results of pollen morphology of Malesian Rubus species are presented. The pollen samples represented 2 subgenera; 2 species of subgenus Chamaebatus (R. calycinus, R. pectinellus) and 13 species of subgenus Idaeobatus (R. acuminatissimus, R. alpestris, R. archboldianus, R. chrysogaeus, R. copelandii, R. ellipticus, R. ferdinandi-muelleri, R. fraxinifolius, R. niveus, R. lorentzianus, R. macgregorii, R. montis-wilhelmi, R. papuanus). The examination of these species has been made by SEM for the first time and also by LM. Detailed descriptions of the pollen grains are given. As in the majority of Rubus species, pollen grains of both subgenera are isopolar and trizonocolporate. The pollen grains were small for some species of the subgenus Idaeobatus only, medium for both subgenera: Chamaebatus and Idaeobatus. The thickest exine was observed among the species of subgenus Chamaebatus and in R. macgregorii of subgenus Idaeobatus. The ornamentation of the studied pollen has shown a great variability. Except for the typical striate ornamentation of the genus, rugulate (R. archboldianus), striatescabrate (R. lorentzianus) and striate-rugulate (R. macgregorii) ornamentation has been observed.New Guinean morphologically similar pinnate Rubus ferdinandi-muelleri, R. montis-wilhelmi, R. papuanus, have pollen with specific type of striate pattern, which is characterised by relatively high muri with variable thickness and lumina filled with granules. Some of their muri resemble baculae typical only for R. chamaemorus. The pollen morphology analysis leads to the conclusion that Rubus montis-wilhelmi and R. papuanus of subgenus Idaeobatus are the closest related species and morphologically very close to R. ferdinandi-muelleri. Since Focke placed the latter species in section Pungentes of the subgenus Idaeobatus, and the two first species were unknown to him - the authors suggest to include them into this section.Despite of the different origin and various types of leaves R. chrysogaeus, R. acuminatissimus and R. niveus have shown similarities in pollen morphology and are grouped together. On the basis of the same criteria, R. copelandii, R. ellipticus and R. fraxinifolius could have been grouped together, as well as R. alpestris and R. macgregorii. Trifoliolate R. archboldianus and R. lorentzianus have not shown similarities of pollen ornamentation to each other and to the previous mentioned species.

An exhaustive search into the Cucurbitaceae pollen literature and own observations were used to arrive at a sharper delimitation of the pollen of subfamily Fevilleoideae against that of the other subfamily, the Cucurbitoideae. Pollen data of 125 out of the 128 genera including all 19 Fevilleoideae genera were available. In view of a broad overlap, pollen grain size is not a reliable criterium to separate both subfamilies. Striate and microstriate ornamentation appeared to be very useful in identifying cucurbitaceous plants as Fevilleoideae. The perforate-rugulate type of Alsomitra is unique in the family. Gerrardanthus cannot be indicated as a member of the Fevilleoideae with pollen features alone, its relatively large (micro)reticulate pollen being similar to that of several Cucurbitoideae. On the basis of outgroup comparison, either striate or perforate-rugulate might be considered as the plesiomorphic ornamentation state in the family Cucurbitaceae. The (micro)reticulate type occurring commonl...

Stratigraphically well-documented seed-cone scales belonging to the conifer genus Araucaria have recently been collected from marine upper Maastrichtian (uppermost Cretaceous) limestones in the type area of the Maastrichtian Stage (NE Belgium, SE Netherlands). These fossils document the youngest known occurrences of the Monkey Puzzle family (Araucariaceae) in Europe, extending the last appearance datum (LAD) for Europe ‘upwards’ in time for c. 18 million years. The cone scales can barely be distinguished from those of the extant Araucaria heterophylla , today confined to Australia. Together with an equally close similarity to an Early Jurassic scale from North America, these finds illustrate the great antiquity and constancy of seed-cone morphology within Araucaria section Eutacta . Climate change and competition with angiosperms, rather than the impact of a large extraterrestrial body (Cretaceous/Paleocene boundary event), led to the demise of Araucaria in the Maastrichtian type area.

The coastal lowland rain forests of eastern Africa are well known for their high levels of plant endemism. A new genus of Annonaceae, Mwasumbia, is described from Tanzania, underscoring this high biodiversity and represented by a single species, Mwasumbia alba. The new genus presents several morphological characters suggesting a close relationship to two other African genera, Greenwayodendron and Polyceratocarpus. Maximum parsimony and Bayesian molecular phylogenetic analyses based on two plastid markers, rbcL and the trnL-trnF region, strongly support the close relationship of these three genera to one another as well as to two other African genera, Annickia and Piptostigma. Together these five genera form a moderately supported clade within the so-called short-branch clade of Annonaceae. A detailed morphological and palynological comparison between Mwasumbia and the four other genera shows that this new genus exhibits a combination of features unique within this group: intermediate tertiary leaf venation, exclusively bisexual flowers, slightly imbricate sepals, valvate petals, outer and inner petals equal in length, numerous stamens, four carpels, few and uniseriate ovules, few and sessile monocarps, and verrucate sulculate pollen grains. Phylogenetic analyses also suggest the genus Piptostigma, as currently circumscribed, to be paraphyletic. An IUCN conservation status of VU D2 is proposed, reflecting the narrow distribution of the single species.

We report the ejection of spores on sporangium dehiscence in the eusporangiate fern genus Angiopteris (Marrattiaceae, Marattiales). Using normal and high-speed video we document movement of the spores and using light and electron microscopy we study the structural changes associated with the movement. The sudden and spontaneous movement covering distances of up to several mm cannot be ascribed to action of the sporangium. We find that cavitation between exospore and perispore wall is the most likely responsible mechanism. We suggest that spore ejection by movement of a spore wall layer may have driven the evolution of an elaborate multilayered spore wall in ferns.

In order to provide additional data for the subdivision of the palaeotropical genus Miliusa (Annonaceae), its pollen was examined using light, scanning and transmission electron microscopy, including 20 of the 30 – 40 species. Further, species of the other genera in the former tribe Miliuseae (Alphonsea, Mezzettia, Orophea, Platymitra; Phoenicanthus not available) and of the Polyalthia cerasoides group, the sister group to Miliusa in a recent molecular analysis, were included. The pollen of Mezzettia and Platymitra is described for the first time with scanning and transmission electron microscopy. The pollen of all species studied with transmission electron microscopy appeared to possess an inaperturate exine, but apertural areas (‘germination zones’) were observed in the intine. The pollen morphological variation within Miliusa does not correlate with the macromorphological subdivision of the genus. It appeared to be impossible to define distinct pollen types. The former tribe Miliuseae cannot be charact...

The Kreftenheye Formation is a fluviatile deposit occurring in the central part of the Netherlands. The present study deals with the plant remains found in suction-dredged bulk samples from its largely Eemian Zutphen Member, a clayey sediment formerly known as the clay–peat bed or the Salvinia bed. It reports the discovery of a large number of galls induced by the asexual generation of the currently southeast European oak gall wasp Andricus hungaricus. The associated plant remains include seeds, fruits, conifer cones, wood, spines, leaf fragments, buds, bud scales, stem fragments, bryophytes, sporangia, oospores, palynomorphs, galls, jet and amber. The palynomorph samples indicate the Late Eemian pollen zone E5b of the Carpinus phase as the origin of the galls, but the other macrofossils may have a wider stratigraphic range, including possibly also material from (a part) of the zones E3–E5a. Several elements, such as Celtis, Chamaecyparis, Juglans, Magnolia and Pterocarya, date almost certainly from earlier interglacials. The list of plant remains is dominated by fresh water plants, riparian elements and ancient woodland taxa, which reflects the ecological range of the IJssel valley and adjacent ice-pushed ridges very well. Thermophilous elements include Brasenia schreberi, Buxus sempervirens, Cornus mas, Najas minor, Salvinia natans, Trapa natans and possibly also Andricus hungaricus. Quercus cerris, the probable host of the sexual generation of A. hungaricus was not found.

Within Rauvolfioideae (Apocynaceae), genera have long been assigned to tribes based mainly on only one or two superficial fruit and seed characters. Taxa with drupaceous fruits were included in Alyxieae. To elucidate relationships within Alyxieae, we analyzed phylogenetically a data set of sequences from four plastid DNA regions (RbcL, matK, TrnL intron, and TrnL-F intergenic spacer) and a morphological data set for 33 genera of Apocynaceae, including representatives of all genera previously included in Alyxieae and two non-Apocynaceae species. Results of parsimony analysis indicate that Alyxieae as previously delimited are polyphyletic, with most genera falling into two main clades. The Alyxia clade includes seven genera: Alyxia Banks ex R. Br., Lepinia Decne., Lepiniopsis Valeton, Pteralyxia K. Schum., and Condylocarpon Desf. together with Plectaneia Thouars. (earlier included in Plumerieae) and Chilocarpus Blume (earlier included in Chilocarpeae). The Vinca clade includes eight genera: Cabucal...

A replacement generic name, Huberantha Chaowasku, is proposed for the recently described genus Hubera Chaowasku segregated from Polyalthia Blume because the name Hubera has been recommended to be treated as a later homonym of Huberia DC. (Melastomataceae) by the nomenclature committee for vascular plants. Consequently, new combinations of twenty-seven species presently recognised are made under Huberantha.

In order to provide additional data for the proposed subdivision of the palaeotropical genus Zehneria (Cucurbitaceae, tribe Benincaseae, subtribe Cucumerinae) by De Wilde and Duyfjes (2006) into five genera (Indomelothria, Neoachmandra, Scopellaria, Urceodiscus and Zehneria s.s.) pollen was examined using light and scanning electron microscopy for 18 Zehneria species including representatives of each of the proposed subdivisions, plus one species of the neotropical genus Melothria to which Zehneria once belonged. The pollen of Indomelothria, Scopellaria and Urceodiscus are described for the first time. Indomelothria, Neoachmandra and Zehneria s.s. have the same pollen type (3‐colporate, microreticulate to reticulate), which cannot be distinguished from that of Melothria. Scopellaria deviates by its irregularly striate‐reticulate ornamentation and short colpi, and Urceodiscus by its striate‐reticulate ornamentation. This result supports separation of Scopellaria and Urceodiscus as separate genera, but neit...

The pollen morphology of 73 species of Acalypha representing most of the taxonomic diversity in the genus was examined with light and scanning electron microscopy, and 14 species with transmission electron microscopy. Acalypha pollen is small (9–22 μm), subisopolar to isopolar or apolar, and oblate-spheroidal to suboblate in meridional outline. The aperture system is 2-8-colporate, with the ectocolpi short (1–5 μm) and almost equal in length to the endopore diameter. Exine ornamentation is rugulate to microrugulate or areolate with distinct scabrae localized on the margins of the muri or scattered over the pollen surface. These results show that Acalypha pollen exhibits significant variation in size, aperture number, aperture distribution and exine ornamentation, and is not homogeneous as previously reported. Two distinct types, each with two subtypes, were recognized based on tectal ornamentation. Though pollen morphology is inconsistent with a phylogeny based on ITS and ndhF sequence data, it does provide support for subgenera Linostachys and Androcephala and several small clades in the molecular phylogeny.

Melodinus pollen has been studied by light, scanning electron and transmission electron microscopy. The pollen grains are usually colporate, medium‐sized monads, and their shape varies from suboblate to oblate spheroidal. They are mostly 3‐aperturate, while four species have pollen with both three and four apertures, and one species has exclusively 4‐aperturate pollen. The ecto‐ and endoapertures show large size ranges. Melodinus coriaceus has its pollen in tetrahedral tetrads, while M. orientalis is polymorphic as to dispersal unit (mostly tetrads, sometimes monads). The monotypic genus Craspidospermum, which is the closest known relative of Melodinus, has its pollen also in tetrads, but these are very different (non‐tetrahedral, irregularly pantoporate). On the basis of pollen morphology, it is hypothesised that tetrads evolved independently in Melodinus and Craspidospermum

The Winteraceae, being considered as one of the most basal angiosperm families, has been extensively studied palynologically. The present study reviews the characters dispersal unit (monad versus tetrad) and size of the lumina in the tectum in the light of recent molecular research. Monads and small-meshed reticula appear to be derived from large-meshed tetrads. The fossil record supports the apomorphic state of a small-meshed tectum. In contrast to earlier reports, genuine monads are unknown as fossils. The fossil monads recorded so far are considered to be detached from permanent tetrad configurations.

Premise of the study: Tribe Miliuseae (~25 genera and ~510 species) includes a substantial part of the species and generic diversity in the pantropical flowering-plant family Annonaceae (~108 genera and ~2400 species). Previous molecular phylogenetic analyses have failed to resolve the backbone phylogeny of the tribe, impeding biogeographical and evolutionary studies. We use a dense generic taxon sample (~89% of generic diversity in Miliuseae) and plastid DNA sequence data (~7 kb) to clarify the phylogenetic relationships of and within the tribe. Methods: Parsimony and Bayesian phylogenetic reconstructions and ancestral character-state reconstructions of several reproductive characters were performed. Key results: Dendrokingstoniae, Monocarpieae, and Miliuseae are recovered in a strongly supported clade, and each tribe is strongly supported as monophyletic. Miliuseae are characterized by a synapomorphic cryptoaperturate/disulculate pollen apertural system. Stenanona is shown to be nested within the paraphyletic genus Desmopsis. The only Neotropical clade (Sapranthus, Tridimeris, Desmopsis, and Stenanona) in the predominantly Asian Miliuseae is shown to be closely related to an undescribed genus from continental Southeast Asia and the Indo-Malayan and Austral-Pacific genus Meiogyne. Ancestral character-state reconstructions of several reproductive characters that are diagnostically important at the generic level indicate a considerable degree of homoplasy. Conclusions: The results improve our understanding of the relationships of and within Miliuseae, but parts of the backbone of the phylogeny remain poorly supported. Additional data from variable nuclear markers or reduced-genome-representation approaches seem to be required to further resolve relationships within this recalcitrant clade

The pollen of the tribe Alyxieae, including Alyxia , Chilocarpus , Condylocarpon , Lepinia , Lepiniopsis , Plectaneia and Pteralyxia , has been studied with light, scanning electron and transmission electron microscopy. It is characterised by relatively large, irregularly disposed and - unequal-sized pores. 2-porate grains are most common in the Alyxieae, and occur in all genera except for Condylocarpon . 1-, 3-, 4- and 5-porate pollen grains are less common. The orientation of the polar axis and the equatorial plane could not be determined in any of the genera. Within the Alyxieae, Chilocarpus and Plectaneia are the nearest to other Apocynaceae, showing an essentially similar exine ultrastructure. Alyxia , Lepinia , Lepiniopsis and Pteralyxia make up a derived group, characterised by large pollen grain size and a remarkable nexine structure. Pollen of Lepinia and Lepiniopsis might be derived on the basis of their fossulate-verrucate ornamentation. Condylocarpon pollen shows a deviating set of pollen feat...

A single specimen of a saleniid echinoid recently collected from the Late Maastrichtian of the type area of the Maastrichtian Stage is notable in being closely related toSalenia nutrixPeron and Gauthier, 1881. Representatives of the “nutrixgroup” have previously been recorded from the Late Cretaceous of the Mediterranean and north Africa. The occurrence in the type Maastrichtian of a representative of this group thus furnishes additional evidence of Tethyan incursions in the area during the Late Maastrichtian.

The pollen of Alstonia has been studied by light and scanning electron microscopy. The pollen grains are always colporate. Four distinct pollen types could be recognized. Type 1 (2‐aperturate) and type 2 (3‐aperturate) have rounded endopores, while type 3 (? 49 μm) possess H‐endoapertures. Probably, all four types have harmomegathically inactive apertures and folding mesocolpia. Type 1 is found in five species of section Alstonia. The other species of this section and the monotypic section Winchia have type 2. The sections Dissuraspermum, Monuraspermum and Tonduzia have pollen type 3. This type may be subdivided on the basis of some minor (overlapping) features, which more or less segregate Dissuraspermum from Monuraspermum. Palynologically, the monotypic American section Tonduzia appears to be most related to the Malesian/Australian/Pacific sections Monuraspermum and Dissuraspermum, and not to the African species of section Alstonia.

For the first time a representative of the echinoid genusTylocidaris Pomel 1883 (Psychocidarinae) is described from the Upper Maastrichtian of the type area of the Maastrichtian Stage. This record represents a new species,T. inexspectata, of which so far only the clavate primary spines are known from the Meerssen Member (Maastricht Formation).

Relatively small, microreticulate-gemmate acalymmate tetrads with coarsely verrucate inner nexine surfaces are described for the monotypic genus Borneosicyos. Tetrads represent a new pollen type in Old World Cucurbitaceae, while microreticulate-gemmate ornamentation and a verrucate inner nexine surface were unknown so far in the entire family.

Juglans bergomensis is the name of a fossil-species belonging to Juglans sect. Cardiocaryon that is based on the basionym Juglandites bergomensis , whose type material, represented by a single fruit, is missing. However, the type locality can be indicated with certainty in the Early Pleistocene brown coal bearing sediments of Leffe, in northern Italy, which yielded several other fossil fruits with characters corresponding to the missing holotype. In the same site fruits of Juglandaceae of different fossil-species occurred. We select a specimen from a collection stored in Padua, with dimensions and sculpture most closely approaching those of the missing holotype, as neotype for the name Juglandites bergomensis , in order to fix the application of the name Juglans bergomensis . Even if the nuts of this species show “seemingly quite minor” differences from those of J. cinerea (smaller seeds, more shallow seed lobes, and generally more elongate shape), it is not convenient to use for these fossils, occurring in Eurasia, the name of the extant North American species. The use of the fossil-species name J. bergomensis, taking priority over J. tephrodes, permits to establish a clear relationship among several hundreds of Eurasian fossils assignable to sect. Cardiocaryon , and to highlight the morphological distinction from a few other fossil-species.

Trace fossils of insect feeding have contributed substantially to our understanding of the evolution of insect–plant interactions. The most complex phenotypes of herbivory are galls, whose diagnostic morphologies often allow the identification of the gall inducer. Although fossil insect-induced galls over 300 Myr old are known, most are two-dimensional impressions lacking adequate morphological detail either for the precise identification of the causer or for detection of the communities of specialist parasitoids and inquilines inhabiting modern plant galls. Here, we describe the first evidence for such multitrophic associations in Pleistocene fossil galls from the Eemian interglacial (130 000–115 000 years ago) of The Netherlands. The exceptionally well-preserved fossils can be attributed to extant species of Andricus gallwasps (Hymenoptera: Cynipidae) galling oaks ( Quercus ), and provide the first fossil evidence of gall attack by herbivorous inquiline gallwasps. Furthermore, phylogenetic placement of one fossil in a lineage showing obligate host plant alternation implies the presence of a second oak species, Quercus cerris , currently unknown from Eemian fossils in northwestern Europe. This contrasts with the southern European native range of Q. cerris in the current interglacial and suggests that gallwasp invasions following human planting of Q. cerris in northern Europe may represent a return to preglacial distribution limits.

Two new species of Neo-uvaria are described from southern Thailand: Neo-uvaria sparsistellata and N. telopea . In addition, new combinations are made for two Mitrephora species from the Philippines: N. merrillii and N. viridifolia . The pollen morphology of eight Neo-uvaria species and three species of the closely related genus Enicosanthum is studied, using light, scanning electron and transmission electron microscopy. The systematic affinity of Neo-uvaria is discussed on the basis of macromorphology, pollen morphology and molecular phylogenetics. The genus Enicosanthum appears to be the closest relative of Neo-uvaria.