POLLEN MORPHOLOGY OF THE TRIBE SWARTZIEAE (SUBFAMILY PAPILIONOIDEAE: LEGUMINOSAE). 1. INTRODUCTION AND ALL GENERA EXCLUDING ALDINA AND SWARTZIA

The pollen morphology of 9 of the 11 genera of the tribe Swartzieae is described together with that of Holocalyx and Cyathostegia, two genera recently removed from the tribe based on macromorphology. The pollen is small, spheroidal to subprolate, primarily tricolporate with a perforate tectum and generally typical of the Leguminosae. Nonetheless, many of the genera have distinctive pollen morphology. Baphiopsis is 6-colporate. The genera Harleyodendron, Lecointea and one species of Exostyles have supratectal spinules. Bocoa viridiflora has striate/rugulate ornamentation very distinct from the other species of the genus Bocoa. The exine stratification is varied but Candolleodendron has a very thick endexine and narrow foot layer. The pollen of African taxa does not differ significantly from that of South American taxa. Pollen morphology does not clarify the taxonomic relationships of the tribe and provides little evidence to assist in positioning Holocalyx and Cyathostegia.     

Molecular phylogeny of the mega‐diverse rove beetle tribe Staphylinini (Insecta,Coleoptera, Staphylinidae)

Chatzimanolis, S., Cohen, I. M., Schomann, A. & Solodovnikov, A. (2010). Molecular phylogeny of the mega‐diverse rove beetle tribe Staphylinini (Insecta, Coleoptera, Staphylinidae). —Zoologica Scripta, 39, 436–449. Phylogeny of the rove beetle tribe Staphylinini is explored by parsimony and Bayesian analyses of sequences of four genes (COI, wingless, Topoisomerase I, and 28S) for 43 ingroup (various genera of Staphylinini) and eight outgroup (two genera of Paederinae, six genera of other tribes of Staphylininae) taxa. Analyses were conducted for each gene independently and for the concatenated data set. Results of the most robust combined analyses were compared with the morphology‐based phylogenies of Staphylinini (‘test phylogeny’), and with the conventional classification of this tribe. Molecular results were congruent with the ‘test phylogeny’ in the following: ancestors of Staphylinini were ‘Quediina‐like’ lineages; formal subtribe Quediina mixes at least two relatively basal groups, ‘Quediina propria’ and ‘southern Quediina’; specialized subtribe Amblyopinina is an internal clade within ‘southern Quediina’; a relatively deeply nested ‘Staphylinini propria’ that unites current subtribes Staphylinina, Eucibdelina, Anisolinina, Xanthopygina and Philonthina is well supported as a monophyletic group. In strong contrast with morphology, molecular data place the tribes Othiini and Xantholinini nested within Staphylinini. Molecular results strongly conflict with morphology by uniting morphologically very different genera Holisus and Atanygnathus in one clade that has uncertain position within Staphylinini. Consistently with the most congruent areas of the morphology‐ and molecular‐based phylogenies, taxonomic changes are implemented for the formal subtribes Quediina and Amblyopinina.     

Pollen morphology of the Pavetteae (Rubiaceae,Ixoroideae) and its taxonomic significance

Pollen grains of the tribe Pavetteae (Rubiaceae, subfamily Ixoroideae) are examined using LM and SEM. Grains are 3‐ or 4‐colporate and (semi‐) tectate (in one Versteegia species atectate). Sexine patterns vary between perforate, microreticulate, reticulate, rugulate and striato‐reticulate. Supratectal elements are sometimes present. The variation in pollen morphology in the Pavetteae allows to recognize seven pollen types, the distribution of which is useful to evaluate generic delimitations and relationships within the tribe. Pollen characters corroborate the close relationships between the genera Coleactina, Dictyandra and Leptactina and between Homollea, Homolliella and Paracephaelis. All the genera of the tribe proved to be stenopalynous (the species examined possess the same pollen type), except Pavetta, Rutidea, Versteegia and Tarenna which are eurypalynous. In the huge genus Pavetta the existing infrageneric classification is supported pollen morphologically. Pollen morphology further indicates that the genus Tarenna is badly delimited and strongly in need of a revision. The small genus Versteegia is in need of further taxonomic and palynological study to understand the pollen morphological variation encountered here. At a higher rank, pollen morphology also does not contradict the recent division of the Pavetteae in the Ixoreae (a stenopalynous tribe with presumably primitive pollen) and the Pavetteae sensu stricto (eurypalynous).     

A survey of species assigned to the fossil pollen genus Anacolosidites

Anacolosidites Cookson & Pike, a fossil pollen genus recorded since the Campanian, is peculiar in its morphology – six‐porate with three apertures on each hemisphere, located away from the equator, and with the distal and proximal apertures positioned over each other. Representatives of this fossil genus are widely considered to represent extant Olacaceae from tribe Anacoloseae. Olacaceae is an exclusively tropical angiosperm family with a pantropical distribution; consequently the fossils are often used to suggest a tropical climate and in addition are frequently used as a stratigraphic marker. Fossil species assigned to Anacolosidites are quite variable and may not all represent Olacaceae, in which case they may not indicate tropical climate.

The present study is a morphological survey of fossil pollen assigned to Anacolosidites; it identifies the published reports of the fossil species that probably represent positive occurrences of Olacaceae pollen in the fossil record. Within Olacaceae, Anacolosidites‐type pollen is usually compared with pollen of genera in tribe Anacoloseae, in particular: Cathedra, Anacolosa and Phanerodiscus, but never with the pollen of Ptychopetalum, a genus from tribe Olaceae with closely similar pollen to the other three genera, but with a reticulate tectum and very small circular apertures located near the equator. Nevertheless, the records of reticulate Anacolosidites species which have been excluded from the emended diagnosis are unlikely to be related to Ptychopetalum. The earliest accepted record of Anacolosidites is from the Late Cretaceous (Maastrichtian) of Germany. However, most Late Cretaceous records, and later Russian and Chinese occurrences referred to Anacolosidites, consist mainly of Normapolles‐type pollen, whereas many of the Cenozoic records assigned to Anacolosidites have a much clearer affinity with the pollen of Anacolosa, Cathedra and Phanerodiscus (tribe Anacoloseae). The newly emended genus Anacolosidites may be used as a stratigraphic marker for tropical or megathermal climatic conditions.     

Pollen morphology of the tribe Rhinantheae (Orobanchaceae) and its systematic significances

Pollen morphology of 36 species representing 14 genera within the tribe Rhinantheae in the family Orobanchaceae was studied and illustrated with light microscopy (LM) and scanning electron microscopy (SEM). Five major pollen types were recognized on the basis of exine ornamentation. Within these major types, minor types (subtypes) were distinguished based on exine surface pattern, size, shape, amb form, colpi and colpus membrane. These types and subtypes are as follows: type I. retipilate: subtype Ia. regular retipilate: (1) pollen size < 27 μm, (2) pollen size > 27 μm, subtype Ib. irregular retipilate; type II. verrucate: subtype IIa. macro-verrucate, subtype IIb. verrucate, subtype IIc. sparse verrucate; type III. retirugulate; type IV. granulate; type V. micro-reticulate. A key to pollen morphology of genera studied within the Rhinantheae was made based on pollen morphology from our study and earlier work. Combining with other sources of information on the Rhinantheae, the systematic relationships of this tribe are discussed. Rhinantheae pollen displays considerable variation between genera and species, with taxonomically significant characters at genus and species level. Palynological characteristics provide evidence for interpreting the conflicting views concerning the “Pterygiella Complex”. The evolutionary trend in exine sculpture of Rhinantheae could be proposed, namely that retipilate sculpturing which is the most widespread type is more primitive than the other types (such as foveolate, granulate, regulate, reticulate, retirugulate and verrucate). The pollen data in present study and the view of Hong (1986), as well as the molecular data from Bennett and Mathews (2006) indicated that Asia and related regions were likely to the origin centre of the tribe Rhinantheae.     

Phylogeny and morphological evolution of tribe Menispermeae (Menispermaceae) inferred from chloroplast and nuclear sequences

The Menispermaceae family contains ca. 72 genera with 450 species that are almost entirely tropical. Its phylogeny at the tribal level has never been examined using molecular data. Here we used DNA sequences of the chloroplast matK gene and trnL-F regions, and the nuclear ITS region to study the delimitation and position of the tribe Menispermeae within the family and its subtribal monophyletic groups. Family-wide phylogenetic analyses of the chloroplast data produced two strongly supported clades. The first clade contains two subclades: Coscinieae including Arcangelisia and Anamirta, and Tinosporeae sensu lato including Fibraureae, supported by morphological characters, such as traits of the cotyledon, stylar scar and embryo. The second clade consists of the tribes Menispermeae sensu DC. and Tiliacoreae Miers. All our analyses surprisingly recognized that tribe Menispermeae is not monophyletic unless tribe Tiliacoreae is included, suggesting that characters of cotyledon and stylar scar are very important for the infrafamilial classification, and that endosperm presence vs. absence was over-emphasized in traditionally tribal division of the family. Our topologies indicate a secondary loss of endosperm. The monophyly of two subtribes of the tribe Menispermeae, Stephaniinae and Cissampelinae, is supported by the cpDNA and ITS data, as well as by morphological characters, including aperture types and shapes, and colpal membrane features of pollen grains, and sepal number of male flowers. The Cocculinae was recognized as a paraphyletic group containing the remaining genera of the tribe Menispermeae.     

The tribal position of Fockea and Cibirhiza (Apocynaceae: Asclepiadoideae): evidence from pollinium structure and cpDNA sequence data

The pollinium morphology of the two members of the Asclepiadoideae, tribe Fockeeae, Fockea Endl. and Cibirhiza Bruyns, has been studied in detail and compared with that of eight genera of Marsdenieae, the tribe in which Fockea and Cibirhiza were previously accommodated and thus their putative closest relatives, as well as nine genera of Asclepiadeae. Both Fockea and Cibirhiza have several morphological characteristics in common, the most important of which is the absence of well-developed caudicula, which distinguishes them from all other genera of Asclepiadoideae known. The pollinium structure of these two genera, however, differs significantly. Whereas the pollinium of Cibirhiza consists of single pollen grains and is covered by a pollinium wall, as is typical for other Asclepiadoideae, the pollinium of Fockea consists of tetrads and is not covered by a pollinium wall, a condition otherwise typical of Secamonoideae. Fockea, however, has only two pollinia per anther, as does Cibirhiza and all other Asclepiadoideae, whereas the Secamonoideae have four pollinia per anther. Sequence data from two intergenic spacers, trnT-L and trnL-F and the trnL intron of cpDNA was analyzed. The ingroup included three species of Fockea and one species of Cibirhiza. The outgroup taxa consisted of three representatives each of Periplocoideae, and Secamonoideae and 24 species of Asclepiadoideae, including representatives of all tribes, of which eight genera belong to Marsdenieae, as outgroups. The results of the DNA analysis provide strong support for Fockeeae as a monophyletic tribe, distinct from Marsdenieae and, to the rest of the Asclepiadoideae. With the exception of pollen data, all morphological and molecular evidence clearly support recognition of the tribe Fockeeae. The occurrence of two such significantly different types of pollinia structure – characters elsewhere in the family used to distinguish subfamilies – within the small tribe Fockeeae was unexpected, and can perhaps best be understood as yet another attestment to the basal position of the Fockeeae in the nascence of the Asclepiadoideae.     

Pollen Morphology of Embothrieae (Proteaceae)

This is the first of two papers detailing pollen morphology and evolution with the tribe Embothrieae comprising eight genera and ca. 56 spp. The present paper examines pollen of subtribes Buckinghaminae (Buckinghamia; 2 spp., Opislhiolepis; 1 sp.), Stenocarpinae (Strangea; 3 spp.), Stenocarpus (ca. 27 spp.) and Lomatiinae (Lomatia; ca. 12 spp.) in the light microscope and scanning and transmission electron microscopes. Pollen is medium-sized, oblate, foveolate to microreticulate to reticulate, and predominantly columellate with a complex modified postvestibulate aperture morphology. Pollen data indicate ties between Lomatia and Stenocarpus on the one hand and Stenocarpus and Strangea on the other. Though Buckinghamia and Opislhiolepis have been placed in the same subtribe, the unique combination of pollen features in each suggests only a remote relationship to each other as well as to remaining Embothrieae. Comparisons to the remaining genera of Embothriae (Embothrium, Oreocallis, Telopea) and overall analysis of pollen evolution within the tribe are detailed in the subsequent paper.     

Pollen morphology and systematics of Atripliceae (Chenopodiaceae)

Pollen morphology of 58 species from 17 putative genera of the tribe Atripliceae (Chenopodiaceae) was investigated using light (LM) and scanning electron microscopy (SEM). Morphological variation was analyzed based on a dense sampling of the subtribes Atriplicinae and Eurotiinae, including many of the species in the two largest genera: Atriplex and Obione. The pantoporate pollen grains of Atripliceae are characterized by their spheroidal or subspheroidal shape, flat or moderately vaulted mesoporia with 21–120 pores, tectum with 1–8 spinules and 5–28(?38) puncta per?µm², and 1–13 ectexinous bodies bearing 1–7 spinules each. Taxonomic relevance of the most important pollen morphological characters is discussed (pollen diameter, pore number, pore diameter, interporal distance, spinule and puncta density and ratio, number of ectexinous bodies, and their spinules). Pollen morphological data support the exclusion of Suckleya from the tribe and the recognition of subtribe Eurotiinae, but suggest that it needs to be reviewed. Pollen does not support generic recognition of Atriplex, Neopreissia and Obione and infrageneric subdivisions as currently recognized, and suggests the need to review them. Smaller or monotypic genera, such as Axyris, Ceratocarpus, Endolepis, Krascheninnikovia, Microgynoecium, Proatriplex and Spinacia have distinctive pollen morphological characters that support their generic status. Grayia needs to be reevaluated; although its two species are distinct from all the other species in the study, there are notable differences between each of them, and this suggests they may not form a natural group. Multivariate techniques were employed to investigate if there are discrete patterns of variation within Atripliceae. Principal Component Analyses (PCA) weakly differentiates four groups based on variation in pore number, puncta density per?µm², and ratio between spinule and puncta density per?µm²; species of Ceratocarpus, Haloxanthium, Krascheninnikovia, Manochlamys, Microgynoecium, Spinacia, and some species of Atriplex and Obione are isolated. Preliminary results indicate that pollen data are potentially useful in the classification of the tribe, and further studies will be of taxonomic value.     

Pollen and the Evolution of Arctotideae (Compositae)

Recent molecular studies have elucidated the phylogeny of Compositae tribe Arctotideae, and found it to contain two, well supported, monophyletic subtribes, Arctotidineae and Gorteriinae, as well as some polyphyletic and problematic genera. On the basis of this new information, it may now be possible to identify diagnostic characters and synapomorphies to support the groupings defined within Arctotideae. Pollen characters have been shown to be particularly variable in Compositae. This paper aims to investigate the utility of those characters in the context of recent molecular phylogenies, in order to determine synapomorphic and diagnostic characters in Arctotideae. The pollen of each genus is described, illustrated with scanning electron micrographs, and optimised on a phylogeny of the tribe. Many pollen characters were found to be very informative when considered in the context of the current best estimate of phylogenetic relationships. Pollen morphology provides synapomorphies for clades at a number of hierarchical levels within Arctotideae, including the two subtribes, Arctotidinae and Gorteriinae, the grouping of Eremothamnus and Hoplophyllum, and smaller clades. It also supports the exclusion of Platycarpha from the tribe. The plesiomorphic palynological state for the tribe is discussed. Particular attention is paid to the evolution of different patterns of lophae (surface ridges). A single origin for the lophate condition is proposed as the most parsimonious mode of evolution in Arctotideae.     

Phylogeny,classification and evolution of the water scavenger beetle tribe Hydrobiusini inferred from morphology and molecules (Coleoptera: Hydrophilidae: Hydrophilinae)

The water scavenger beetle tribe Hydrobiusini contains 47 species in eight genera distributed worldwide. Most species of the tribe are aquatic, although several species are known to occur in waterfalls or tree mosses. Some members of the tribe are known to communicate via underwater stridulation. While recent morphological and molecular‐based phylogenies have affirmed the monophyly of the tribe as currently circumscribed, doubts remain about the monophyly of included genera. Here we use morphological and molecular data to infer a species‐level phylogeny of the Hydrobiusini. The monophyly of the tribe is decisively supported, as is the monophyly of most genera. The genus Hydrobius was found to be polyphyletic, and as a result the genus Limnohydrobius stat. rev. is removed from synonymy with Hydrobius, yielding three new combinations: L. melaenus comb.n. , L. orientalis comb.n. , and L. tumbius comb.n. Recent changes to the species‐level taxonomy of Hydrobius are reviewed. The morphology of the stridulatory apparatus has undergone a single remarkable transformation within the lineage, from a simple, unmodified pars stridens to one that is highly organized and complex. We present an updated key to genera, revised generic diagnoses and a list of the known distributions for all species within the tribe.     

Floral morphology and taxonomic relations among the genera of Amaranthaceae in the New World and the Hawaiian Islands

Twenty-three genera of Amaranthaceae occur in the New World. Two endemic genera occur in the Hawaiian Islands. Among the genera of the subfamily Amaranthoideae, Celosia, Cyathula and Achyranthes have their main distributions in the Old World; the two last-named genera are represented in the Americas only by widespread weeds. All the New World genera of the subfamily Gomphrenoideae are mainly or entirely restricted to this region. Characters of androecium and gynoecium are fundamental in the recognition of genera within the family. Androecia of different genera may be structurally and phylogenetically more similar than would appear from a cursory examination. It is suggested that the type of staminal tubes found in Pseudogomphrena and Froelichia can be derived from that in Alternanthera and Froelichiella by reduction of filament length and a fusion of pseudostaminodia with the filaments. The staminal tube in Gomphrena could result from a further decrease in distance between pseudostaminodia of the Pseudogomphrena type, and a deeper forking of the pseudostaminodia; each so-called apical filament lobe in Gomphrena would then be homologous with half a pseudostaminodium in Pseudogomphrena. Much of the variation in the androecia of these and other genera, as well as within genera such as Pfaffia, can be explained as the combined results of coalescence and splitting-up tendencies. Splitting up of staminal tubes may not necessarily take place along the borders of phylogenetically original filaments and pseudostaminodia. The Amaranthus-type of pollen is found in the majority of genera of the subfamily Amaranthoideae, but also in the Chenopodiaceae. A group of genera within the subfamily Gomphrenoideae also has pollen very similar to, or identical with, this type. Most genera of the subfamily Gomphrenoideae have pollen of the Gomphrena-type. Pseudoplantago has unilocular (at anthesis) anthers, a characteristic of the subfamily Gomphrenoideae, but floral structure as well as pollen morphology connect the genus to a group of genera within the Amaranthoideae, subtribe Achyranthinae. The combination of subcuboidal shape and opercula with radially arranged hooked protuberances, makes the pollen of Pseudoplantago unique among the angiosperms studied so far. Floral morphology and palynological characteristics indicate a close relationship between Pfaffia and Alternanthera. Both genera, as currently accepted, are relatively homogeneous from pollen morphological points of view. There are no correlations between pollen morphology and the variation in the androecium in Pfaffia, nor would pollen structure support recognition of Hebanthe as a distinct genus. Woehleria and Irenella may be derived from, or be of the same origin as, Dicraurus and Iresine. All four genera are placed in the subfamily Gomphrenoideae because of the bisporangiate anthers, but their pollen structure is very close to, or identical with, that of the Amaranthus-type. Pseudogomphrena combines characteristics of Gomphrena and Pfaffia.     

Pollen morphology and evolution in the genus Orobanche L. s.l. and its allied genera (Orobancheae/Orobanchaceae) in Turkey

The pollen morphology of 120 samples of the tribe Orobancheae, representing four genera and 40 species of Cistanche, Diphelypaea, Orobanche and Phelipanche native to Turkey, has been studied by light and scanning electron microscopy. Pollen of the tribe Orobancheae is typically isopolar, radially asymmetrical, oblate spheroidal or prolate and belongs to one of the following basic pollen types: inaperturate, tricolpate and syncolpate. Also, pollen heteromorphism is widespread among pest species of Orobanche and Phelipanche. Pollen characters display considerable variation among genera and species, but some characters are significant at the levels of genera and sections. The results of the SEM study show that there are various exine ornamentation types in these genera. The obtained results support the division of the traditionally circumscribed genus Orobanche sensu lato into two genera, Phelipanche and Orobanche. The pollen morphological features are discussed on the basis of molecular phylogeny of the taxa.     

毛茛科分子系统发育研究进展

毛茛科(Ranunculaceae)在被子植物的系统演化中占有十分重要的地位,其系统位置和科下演化关系一直备受争议。近20多年的分子系统学研究表明,以往基于形态学的分类系统与分子系统学研究结果存在巨大差异。通过形态学性状界定的绝大多数亚科都没有得到分子系统学支持。此外,通过形态学确定的一些属如升麻属(Cimicifuga)、黄三七属(Souliea)、獐耳细辛属(Hepatica)、白头翁属(Pulsatilla)和水毛茛属(Batrachium)等,根据分子系统学研究均应予以归并。而分子系统学研究也确立了一些类群的属级地位,如露蕊乌头属(Gymnaconitum)等。以中国分布的毛茛科植物为例,通过以往分子系统学研究,共有10个属被归并,2个属新被确立。然而,毛茛科分子系统学研究对于科下许多类群之间的关系目前仍然没有得到很好的解决,如毛茛亚科和翠雀族等类群的系统发育关系仍需要进行深入研究后方能确定。该文对近年来国内外有关毛茛科的分子系统学研究进展进行了综述,并对该科尚存的一些问题和未来的研究方向进行了讨论。     

Pollen morphology of the tribe Lithospermeae of Boraginoideae in China and its taxonomic significance

The pollen morphology in 15 species representing five genera in the tribe Lithospermeae of Boraginoideae (Boraginaceae) has been investigated and illustrated using light microscopy and scanning electron microscopy. The tribe Lithospermeae is very diverse in pollen morphology. The pollen grains are 10.4–41.8 × 7–33.1 μm in size with subspheroidal, prolate, cocoon, dumbbell, and ovoid shapes. The pollen apertures are of five types: 3-colporate, 3-syncolporate, 4-8-colporate, 4-6-syncolpate, and 6-7-colpate types. The exine ornamentations are generally smooth or rugulose, sparsely echinulate, and rarely rugulate. Based on pollen morphology, we developed a key to identify the genera of the tribe Lithospermeae, compared the pollen apertures among tribes of Boraginoideae, explained the evolutionary trends of the pollen grains, and discussed the taxonomic position of the tribe Lithospermeae. The palynological data suggest pollen of the eurypalynous type and support the proposal that the tribe Lithospermeae is in the primitive position of the subfamily Boraginoideae, and Echium Linn. is in the tribe Lithospermeae rather than in a novel tribe. Our observations have application potential for identification of pollen fossils of the tribe Lithospermeae.     

Gaertnera and Pagamea: Genera Within the Psychotrieae or Constituting the Tribe Gaertnereae? A Wood Anatomical and Palynological Approach

The possible alliance between Gaertnera and Pagamea (Rubiaceae-Rubioideae), two genera from the Old and New World, respectively, is investigated on the basis of wood anatomy and pollen morphology. Nowadays, the main point of discussion about the taxonomic position of these genera is whether they belong to the Psychotrieae or constitute a tribe Gaertnereae characterised by their secondarily superior ovary and sheathing stipules. Both the wood and pollen of the genus pair are found to show specific features absent in other genera of the Psychotrieae, e.g. parenchyma bands in the xylem and endexine thickenings on the polar sites of the pollen apertures. Nevertheless Gaertnera and Pagamea share many other characters with the Psychotrieae. Wood and pollen convincingly demonstrate the very close affinity of the two genera. The sister pair differs in so many features from other Psychotrieae, that Gaertnera and Pagamea should constitute at least a subtribe Gaertnerinae, formally recognized here. The general lack of profound studies on the affinities within the very large tribe Psychotrieae makes further comments on the taxonomic relationships of the Gaertnerinae difficult.     

POLLEN MORPHOLOGY AND SYSTEMATIC RELATIONSHIPS AMONG NEW WORLD SPECIES IN TRIBE ANTIRRHINEAE (SCROPHULARIACEAE)

The morphology of mature pollen grains among 12 New World genera in tribe Antirrhineae has been examined with light and scanning electron microscopy. Pollen from 29 American species have mean polar diam that range from 17 to 26 μm, have a tectate structure with perforate, microreticulate, or reticulate surface pattern, and are subspheroidal to prolate, and trizonocolporate with fusiform or narrowly oblong colpi that are free or occasionally fused at the poles. Among the genera, pollen size is positively associated with style length but not haploid chromosome number. Three major morphological categories are recognized based on grain shape, exine structural pattern, and colpus shape. Two of these morphotypes each characterize individual genera (Mohavea, Linaria). The other morphological category includes ten New World genera and has been divided into three subcategories based on variation in lumina diam and intermittent occurrence of fused colpi. Only Antirrhinum and Pseudorontium have species or populations with pollen in more than one subcategory. Concordance of morphological, anatomical, chromosomal, and palynological data suggests that Linaria and Mohavea are best placed in separate subtribes from other native American genera. Compared to Old World taxa in tribe Antirrhineae, the most common pollen type (subspheroidal, microreticulate, apocolpate, fusiform colpi) may be the most primitive. Pollen grains with fused colpi (Antirrhinum p.p., Pseudorontium) and perforate (Mohavea) or reticulate (Holmgrenanthe) structural patterns probably represent derived types.     

Pollen morphology of the subfamily Aurantioideae (Rutaceae)

The Aurantioideae is one of seven subfamilies of the Rutaceae consisting of two tribes, the Clauseneae, containing five genera, and the Citreae, with 28 genera. Each tribe contains three subtribes. The pollen morphology of the subfamily Aurantioideae is described and illustrated for the first time based on light and scanning electron microscopy. Five pollen types have been recognised in the subfamily, based mainly on aperture number and exine ornamentation. The pollen grains show a high degree of intergeneric variation. Pollen grains of Clauseneae are 3-colporate, microstriate or microstriato-reticulate, whereas pollen grains of Citreae are almost always 4/5 colporate with exines varying from microperforate to coarsely reticulate. Congruence between pollen types and the currently accepted classification is discussed, as well as the systematic implications of pollen morphology for the subfamily.     

POLLEN MORPHOLOGY IN THE GENERA MONTTEA AND MELOSPERMA (SCROPHULARIACEAE)

Pollen of the scrophulariaceous genera Melosperma and Monttea was studied with light and scanning electron microscopy. Both have single, radiosymmetric, isopolar, trizoniaperturate pollen grains with usually ruptured colpus membranes, tectate-perforate to semitectate exines with a columellate interstitium and pitted or perforate nexines. Intergeneric differences in pollen morphology are established based on the differential correlation of sculpturing characters. Comparisons of the pollen of Melosperma and Monttea with that of the tribe Minuleae sensu stricto reveals no difference in the case of Melosperma and the existence of intermediate morphologies and “reticulate” similarities in the case of Monttea; the taxonomic significance of this morphological intergradation is considered. The transfer of Oxycladus aphyllus to Monttea is consistent with the pollen evidence, but proposed affinities between Monttea and tribe Antonieae of the Loganiaceae are not supported.