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Cneorum trimerum (Urban) Chodat is only known from the type specimen collected in 1861 in eastern Cuba. The species has sometimes been regarded as a synonym of C. tricoccon L., which is otherwise confined to the Mediterranean. As no other Cneorum specimens are known from Cuba, the specimen is a mysterious finding with a disputed taxonomic rank. The goal of this study is to clarify the status of the Cuban specimen using molecular and wood anatomical data. We succeeded in extracting DNA out of the 150 year old type specimen in our ancient-DNA lab and amplified two chloroplast markers (atpB, trnL-trnF) and one nuclear marker (ITS). Comparison of the sequence data with several sequences from C. tricoccon clearly suggests inclusion of the Cuban specimen into the latter species; wood anatomical features confirm the molecular results. The transatlantic distribution of C. tricoccon is probably the result of an introduction in Cuba by humans.

This study presents a description of the morphology and anatomy of the fruits and seeds of Adoxa, Sambucus, and Viburnum. A phylogenetic study included Adoxa moschatellina, Sinadoxa corvdalifolia, Sambucus, Tetradoxa omeiensis, and Viburnum. All major clades of Caprifoliaceae, the sister family of Adoxaceae, were sampled and used as outgroup. Maximum parsimony and Bayesian inference optimality criteria were used to analyze three datasets, molecular data (ITS, trnK, matK), morphological data (21 fruit and seed characters), and a combined dataset. We used parsimony optimization to study character evolution. Results of the phylogenetic analyses were congruent with previously published results. Viburnum is the basalmost lineage in the family and sister to subfamily Adoxoideae. In Adoxoideae, Sambucus is sister to the Adoxina clade (i.e., Adoxa, Sinadoxa, and Tetradoxa). Our results also confirmed the sister relationship between Sinadoxa corydalifolia and Adoxa plus Tetradoxa. For the first time, clear autapomorphies are described for Sambucus, such as a long, slender, cylindrical embryo, sclereids with a u-shaped sclerification pattern, a rugose endocarp surface, and numerous, small calcium oxalate crystals in the endocarp sclereids. Character evolution in Sambucus, however, is complex and a broader sampling is required to draw firm conclusions. The evolution toward Viburnum is marked by a number of shifts such as the development of small, amorphous crystals in endosperm cells and a well-developed, parenchymatous seed coat. Based on our results and previous studies we hypothesize a paedomorphic event took place at the origin of Adoxina. Evidence supporting this hypothesis is the presence of green fruits, weakly sclerified endocarp sclereids, small seeds, and semi-inferior ovaries in Adoxina. Finally, our results indicate that the first Adoxaceae were characterized by tricarpellate ovaries with an endocarp composed of an outer layer of sclereids and an inner layer of fibers. A thorough study of the fruits and seeds of Sinadoxa and Tetradoxa is vital to fully understand fruit and seed evolution in Adoxaceae.

Impatiens msisimwanensis S.B. Janssens and E.B. Knox is described as a new species from the Udzungwa Mountains in Tanzania. A comparative morphological study illustrates the affinity between the newly discovered species, I. nana and I. sylvicola . Using a molecular approach we assessed the phylogenetic position of I. msisimwanensis among the East African Impatiens species, thereby confirming its status as a new species. In addition, the pollen morphology of I. msisimwanensis was thoroughly examined.

Within the Cyperoideae, which comprise all Cyperaceae except the Mapanioideae, several questions of homology are discussed and reinterpreted based on results of our SEM and LM floral ontogenetic studies. In all species studied, spikelets are interpreted as being indeterminate, with spirally to distichously arranged glumes, each subtending (or not) a flower. Floral development starts with the formation of two lateral stamen primordia, simultaneously with, or followed by the formation of a third, abaxial stamen primordium. Perianth parts, if present, originate only after the formation of the androecium, simultaneously with the appearance of an annular ovary primordium, surrounding a central ovule primordium. Perianth parts vary in number and morphology, and, where present, perianth development follows a general pattern. Three (or two) stigma primordia are formed on the top of the rising ovary wall. In dimerous gynoecia, stigma primordia originate either dorsiventrally, resulting in a laterally flattened ovary/nutlet, or laterally, resulting in a dorsiventrally flattened ovary/nutlet. We conclude that in all species studied the spikelet and floral development occurs according to a general, scirpoid, ontogenetic pattern, which we illustrate using new spikelet and floral ontogenetic results in Eleocharis palustris and other species. Spikelet and floral ontogeny in species with apparently deviating morphologies, can be traced back to the general ontogenetic pattern.Varias preguntas sobre homologia para las Cyperoideae, que incluyen todas las Cyperaceae excepto las Mapanioideae, se discuten e interpretan con base en estudios de ontogenia floral realizados con SEM y LM. En todas las especies estudiadas, las espiguillas son indeterminadas con glumas arregladas en espiral o dicotomicamente, cada una sosteniendo (o no) una flor. El desarrollo floral comienza con la formaciA(3)n de dos primordios estaminales laterales, simultaneamente con o seguido por la formaciA(3)n del tercer primordio estaminal abaxial. Si se desarrollan las partes del perianto, se originan solo despu,s de la formaciA(3)n del androceo, simultaneamente con el desarrollo del primordio anular del ovario que envuelve al primordio central del A(3)vulo. Cuando estan presentes las partes del perianto, varian en nA(o)mero y morfologia y el desarrollo sigue un patrA(3)n general. Se forman tres (o dos) primordios del estigma en el apice de la pared del ovario en desarrollo. En gineceos dimeros, los primordios de los estigmas se originan dorsiventralmente resultando en una nuececilla/ovario comprimido lateralmente, o se originan lateralmente, resultando en una nuececilla/ovario comprimido dorsiventralmente. Concluimos que, tanto el desarrollo floral, como el de las espiguillas en todas las especies estudiadas, siguen un patrA(3)n ontogen,tico general scirpoide que se ilustra con los resultados obtenidos para Eleocharis palustris y otros especies. La ontogenia floral y de las espiguillas en especies con morfologias aparentemente atipicas, puede estar reducida al patrA(3)n ontogenetico general. ispartof: The Botanical Review vol:75 issue:1 pages:30-51 ispartof: location:Vienna status: published

Pollen and orbicule morphology of 84 species, representing 52 genera from all tribes and subfamilies are investigated, in order to assess the systematic value of palynological data and to determine palynological evolutionary trends in Cyperaceae. A total of 90% of the species are examined for the first time with scanning electron microscopy. Pollen grains of Cyperaceae are oblate spheroidal to perprolate in shape, inaperturate to polyporate with opercula or pontopercula on pori or colpi. We distinguished seven different sexine ornamentation patterns. Orbicules occur in all species investigated. Pollen morphological variation within Cyperaceae is considerable and includes dispersal unit; number, location and degree of differentiation of apertural zones; and sexine ornamentation patterns. In subfamily Mapanioideae both tribes can be characterized by palynological synapomorphies. However, in subfamily Cyperoideae, the observed pattern of variation does not fit the most recent molecular phylogeny due to high levels of homoplasy and polymorphism in major pollen characters.

The balsaminoid Ericales, namely Balsaminaceae, Marcgraviaceae, Tetrameristaceae, and Pellicieraceae have been confidently placed at the base of Ericales, but the relations among these families have been resolved differently in recent analyses. Sister to this basal group is a large polytomy comprising all other families of Ericales, which is associated with short internodes. Because there are more than 13 kb of sequences for a large sampling of representatives, a thorough examination of the available data with novel methods seemed in place. Because of its computational speed, Bayesian phylogenetics allows for the use of parameter-rich models that can accommodate differences in the evolutionary process between partitions in a simultaneous analysis. In addition, there are recently proposed Bayesian strategies of assessing incongruence between partitions. We have applied these methods to the current problems in Ericales phylogeny, taking into account reported pitfalls in Bayesian analysis such as model selection uncertainty. Based on our results we infer several, previously unresolved relationships in the order Ericales. In balsaminoid families, we find that the closest relatives of Balsaminaceae are Marcgraviaceae. In the Ericales polytomy, we find strong support for Pentaphylacaceae sensu APG II as the sister group of Maesaceae. In addition, Symplocaceae receive a position as sister to Theaceae and these families form a monophyletic group together with Styracaceae–Diapensiaceae. At the base of this clade are Actinidiaceae and Clethraceae. The positions of Ebenaceae and Lecythidaceae remain uncertain.

DNA sequences of both 5′ and 3′ regions of the plastid ndhF gene were generated in order to study the position of Patrinia and Nardostachys, to check the potential paraphyletic nature of Patrinieae, and to evaluate the possible link between the tribe and Linnaeaceae. Parsimony analysis showed very strong support for Patrinia as sister to all members of Valerianaceae (including Nardostachys) and indicated the paraphyletic nature of the tribe Patrinieae. Additionally, trees were constructed from available rbcL data separately and supplemented with ndhF sequences. Topologies of these combined cladograms are in agreement with the ndhF phylogeny, suggesting that the traditionally circumscribed Patrinieae can no longer be recognized but must be considered as part of a basal grade in Valerianaceae. Parsimony analysis based on a morphological data set supported a monophyletic Patrinieae; combination with the molecular data showed a paraphyletic Patrinieae. Furthermore, the possible link between Patrinieae and Linnaeaceae is evaluated.

Background: In the locules of anthers of flowering plants, tiny (1.5-2 µm) granules of sporopollenin may occur next to the pollen grains. Those granules, called orbicules, mostly occur on the radial and innermost tangential wall of secretory tapetum cells. Methods: We have investigated the presence of orbicules in 15 important European allergenic species with scanning electron microscopy (SEM). Results: Orbicules were present in all species investigated of the families Betulaceae, Chenopodiaceae, Fagaceae, Poaceae, Polygonaceae, and Urticaceae. However, in the Asteraceae and Oleaceae species studied, orbicules were lacking. In all Chenopodiaceae, Poaceae, and Urticaceae species, orbicules were attached to the pollen exine. These observations indicate the possibility of the dispersal of orbicules into the atmosphere during anthesis. Conclusions: The hypothesis of the potential role of orbicules as possible important vectors of allergens is put forward, based on the comparison of our results with recent literature about the evidence of allergenic activity in the smaller micronic atmospheric aerosol fraction. Our results provide evidence that an in-depth investigation of the sites of allergens across the whole anther is required. We suggest that allergen researchers apply immunoelectron microscopy on whole anthers to determine whether orbicules possess allergens.

Melianthus has strongly modified and monosymmetric (zygomorphic) flowers, and the ontogenetic derivation and evolutionary origins of these highly modified flowers are sought in a comparative study of the floral ontogeny and anatomy of two species of Melianthus and one species of Bersama. The development of monosymmetry in the family can be observed as a stepwise process linked with displacements of organ primordia and selective losses of petals and stamens. Flowers are weakly (Bersama) to strongly (Melianthus) monosymmetric. Sepal initiation is divided into two time sequences: the three outer sepals arise simultaneously with the anterior sepals behaving as a shielding unit before the two inner sepals emerge. Similarities and differences between the two genera are shown to be related to the trend to monosymmetry and are linked to specific pollination strategies. In Melianthus, an abaxial petal primordium is initiated, but it aborts at an early stage of development; in Bersama, all petals are present, but t...

Coccocypselum is a small neotropical genus of creeping herbs belonging to the Rubiaceae (Rubioideae). A recent macromolecular study suggested a previously unknown relationship between Coccocypselum and two other neotropical genera, Declieuxia and Hindsia, but the morphological evidence for this relationship was obscure. In the present paper, morphological characters supporting the conclusions from macromolecular data are presented. The most important similarities between Coccocypselum, Declieuxia, and Hindsia are found in their pollen and stipule morphology. Pollen of the three genera share a typical exine ornamentation, called a complex reticulum, which consists of a psilate suprareticulum and spinulate infrareticulum. In some specimens of Hindsia longiflora, a transitional stage between a complex reticulum and a simple, spinulate reticulum is encountered. The interpetiolar stipules of Hindsia, Declieuxia and Coccocypselum have an identical basic structure: they bear a central, colleter-tipped awn that extends downwards to the next node as a distinct stem ridge. Some less conspicuous similarities of habit, calyx, and corolla are also discussed. The morphological data are, in part, confirmed by distributional data, Declieuxia and Hindsia having a remarkably congruent centre of diversity in the southeast of Brazil. It is concluded that the macromolecular data, combined with this new morphological and distributional evidence, justify an extended tribe Coccocypseleae, comprising the genera Coccocypselum, Hindsia, and Declieuxia.

Aluminium (Al) accumulators are plants which accumulate more than 1000 ppm Al in their tissues. In addition to earlier analyses on leaves of Rubiaceae, 251 specimens were tested to verify the systematic importance of this character. The distribution of Al accumulators in the family shows that the feature is more or less restricted to a widely circumscribed subfamily Rubioideae including Craterispermeae, Knoxieae, Urophylleae and Pauridiantheae. Other Rubioideae representing strong Al accumulators are the genus Coccocypselum, Coussareeae, Prismatomerideae, and most Psychotrieae. It is hypothesized that the ability to accumulate high levels of Al evolved in an ancestor of the Rubioideae s.l. since the feature is concentrated in basal taxa of this subfamily. Moreover, recent phylogenetic insights in the subfamilial classification of the Rubiaceae based on macromolecular data are confirmed. Al accumulation is reported in only two genera outside Rubioideae s.l., viz.Coptosapelta and Alberta. Al accumulators generally are woody, relatively primitive taxa which occur in tropical forests with relatively high rainfall. In more derived Rubioideae such as Anthospermeae, Hedyotideae, Paederieae, Rubieae and Spermacoceae the tendency to herbaceousness is possibly associated with the absence of Al accumulation. It is likely that this lack is related to their adaptation to more xeric, alkaline soils and their more temperate distribution.

We studied the interrelation between nectary structure (13 parameters), nectar characteristics (yield, chemical composition), and flower size of 11 Labiatae species in a Mediterranean shrub community near Athens, Greece. We also explored whether the above attributes are affected by the Mediterranean summer drought constraints. Our findings show that among all nectary parameters studied, nectary size and stomatal opening are the most important in (positively) shaping nectar secretion, nectary size being the most meaningful. Nectary structure is correlated to quantity of the nectar secreted, not its quality. Wide flowers bear wide nectaries with large stomatal openings, whereas deep flowers are not related to any nectary size. Corolla size (both length and width) and nectary stomatal opening decrease with flowering time. This applies also to nectary size, nectar volume and sugar content of the perennials (9 species). All above cases of time dependence show that there is a constraint effect of Mediterranean climate on floral and nectary structure, reflected also as a decrease in nectar secretion. Nectary structure in Labiatae is largely shaped by both phylogenetic and climate constraints. On the other hand, although nectar is largely influenced by nectary structure, it is to a large extent ecologically biased, implying that, in addition to phylogeny, there are many other ecological parameters interfering in its secretion such as time within the season, life history, and light requirements.

Floral development and anatomy of Carica papaya L. have been investigated to shed light on (i) the morphology of the flower, (ii) the structural basis for the pollination mechanism, and (iii) the relationships of the Caricaceae. Carica is mostly dioecious with a strong dimorphism between staminate and pistillate flowers. The development of staminate flowers resembles that of pistillate flowers up to the initiation of the stamens. Further development leads to highly diverging morphologies. In staminate flowers a combination of contorted growth and the development of a common stamen-petal tube produces a long floral tube. The gynoecium grows into a central spearlike pistillode. The pistillate flowers have no traces of stamens and initiate five antesepalous carpel primordia. Common basal growth leads to the development of a large ovary with staglike stigmatic lobes and intruding placentae covered with numerous ascending ovules. Floral anatomy of staminate and pistillate flowers is described. The nature of the colleters is discussed. The morphological basis for reward production in C. papaya is clarified, and conflicting views on pollination are discussed. Nectaries of staminate flowers are located on the central rudimentary pistil and not at the base of the stamens, as previously reported. The anthers contain packages of calcium oxalate crystals. Pistillate flowers produce no nectar but have a stigmatic exudate. We compared the floral development and anatomy of Carica with that of Adenia (Passifloraceae) and Moringa (Moringaceae) in the view of a relationship with other glucosinolate-producing families. Although a derivation of the unisexual flowers from bisexual ancestors is probable, Storey's hypothetical derivation of pistillate flowers is not supported by the floral ontogeny and vasculature.Key words: Adenia, Caricaceae, Moringa anatomy, calcium oxalate packages, dioecy, floral structure, nectaries, ontogeny, pollination, systematic relationships.

The floral development and anatomy of Chrysosplenium alternifolium were studied with the scanning electron microscope and light microscope to understand the initiation sequence of the floral organs and the morphology of the flower, and to find suitable fl

In order to improve understanding of the systematic relationships between taxa and of tepal–pollinator and tepal–habitat relationships, a detailed scanning electron microscopy (SEM) study of the adaxial tepal surface of 135 taxa belonging to c . 14 genera in the tribes Persicarieae and Polygoneae (Polygonoideae–Polygonaceae) was carried out. The tepal surfaces have revealed some striking differences among the genera studied. Three main patterns of sculpturing and cell shape can be recognized. Type I: mostly rectangular to elongate cells with straight or undulating anticlinal walls; the cuticles smooth or striate in longitudinal direction and often continuous ( Persicaria , Bistorta , Aconogonon , Koenigia and some species of Fagopyrum ). Type II: irregular tesselated to elongated cells, rarely rectangular with mostly sinuate anticlinal walls; the cuticles rarely with longitudinal striation, but with strong orthogonal to reticulate ridges or striae, often without correlation between cells ( Polygonum s.s. , Polygonella , Fallopia , Parapteropyrum , Pteropyrum , Atraphaxis and Calligonum ). Type III: mostly irregular, mammilliform, papillose cells with either longitudinal tightly pressed or randomly ridged cuticles (some species of Fagopyrum and Oxygonum ). The present data generally support the division of Polygoneae and Persicarieae by Ronse Decraene & Akeroyd. The mammilliform, papillate epidermis of tepals in Oxygonum and some Fagopyrum is probably well-adapted to entomophily either as a foothold or even as a light-trap, and also shows some correlation with heterostyly. It is noteworthy that the tepal structure of Polygonella (tesselated form) is highly similar to that of Polygonum s.s. (especially P. sect. Duravia ). Cuticular striation alone does not appear to have much systematic value, but has a mechanical function in affording extra strength to the cell walls. Some correlations between the degree/shape of cuticles and the pollination mechanisms or the habitat of each taxon are also briefly discussed. It is concluded that the studied tepal characters can be useful in improving the classification of tribes Persicarieae and Polygoneae, and give additional support at the infrageneric level.

This paper aims to summarize briefly and to update our ideas about androecial architecture formulated in earlier publications. Ontogenetic evidence of stamen development, viz. the initiation, arrangement and relationship of stamens to other floral morphomes, can be translated into a semophyletic scheme reflecting the phylogeny of the androecium. The ancestral androecium is discussed in the light of recent theoriesabout angiosperm phylogeny. Two divergent androecial processes are proposed for the angiosperms starting from a spiral androecium with a moderate number of stamens. However, transitions exist between spiral polyandry, numerous stamens in whorls, and chaotic polyandry. From an androecium with several alternating whorls of paired and single stamens, outer stamen pairs are retained following the successive loss of inner stamen whorls. Single stamens instead of pairs occur at the very end of this line and represent a more advanced condition. This line is mostly present in tri- and dimerous flowers. From the same starting point diplostemony (with two alternating whorls of single stamens) originated, again giving rise to various states usually present in pentamerous or tetramerous flowers.

The floral ontogeny of the monotypic genus Monococcus (Phytolaccaceae) is investigated with the scanning electron microscope. Flowers arise on pendent racemes and are preceded by a bract and two bracteoles arising successively. In both staminate and pistillate flowers four sepals are incepted in diagonal position. In the staminate flowers four alternisepalous stamens are initiated successively. Further stamen inception occurs centrifugally and runs concomitant with peripheral growth of the receptacle. This centrifugal stamen initiation is interpreted phylogenetically as a secondary increase and is expressed by the appearance of four triplets. Initiation of a variable number of outermost stamens (0–8) occurs mostly in the latero-abaxial region of the flower. In staminate flowers there is no trace of a gynoecium. In pistillate flowers a gynoecium primordium arises centrally and grows into a monocarpellate structure. Later, hooked bristles arise on the carpel flanks while a short style is produced bearing a distal tangle of long hairs. A close relationship of Monococcus with Petiveria is confirmed; similarities include the median position of the prophylls, the diagonal position of four sepals, the sequential inception of four alternisepalous stamens, and the fruits with adaptations for exozoochory. Key words: androecium, floral ontogeny, Monococcus, Phytolaccaceae, Rivinoideae.

As a first step towards a broader floral ontogenetic study on Cornales, the flowers of four species of Hydrangeaceae (Deutzia corymbosa, Kirengeshoma palmata, Philadelphus purpurascens and Hydrangea petiolaris) were studied. In Deutzia and Kirengeshoma five sepal primordia are generally initiated, in Philadelphus only four. Sepal initiation in Kirengeshoma shows a tendency to tetramony. Deutzia has a variable sepal initiation. Petal growth was never retarded in the studied species. Initiation of the androecium in Kirengeshoma, Philadelphus and Hydrangea starts with antesepalous primary primordia, on which secondary primordia are soon formed, leading ultimately to the formation of polystaminate androecia. In Deutzia a diplostemonous androecium is formed, starting with the initiation of the antesepalous stamen primordia. Gynoecium development is similar in all species studied: on a concave floral apex, a ring meristem is initiated; it develops into a variable number of continuous carpel primordia, while the centripetally growing common margins form the septa. Initiation of the ovule primordia starts halfway up each placenta and extends in an apical, basal and lateral direction. A number of morphological problems are discussed, such as the derivation of tetramery, and evolutionary and developmental trends in the androecium and gynoecium. Kirengeshoma is well settled in Hydrangeaceae, although its exact position within the family remains uncertain. A sistergroup relationship of Hydrangeaceae with Loasaceae is supported. However, Hydrangeaceae also share features with Saxifragaceae (e.g. similar gynoecium development).

Sixteen species of 14 genera of 7 different tribes of the Cinchonoideae (Rubiaceae) were investigated with a scanning electron microscope to examine orbicule presence and morphological diversity. Orbicules are lacking only in Gouldia terminalis (Hook, et Arn.) Hbd. and Simira rubescens (Benth.) Bremek. ex Steyerm. Four orbicule types could be distinguished mainly on the basis of shape and ornamentation characteristics. Spiny orbicules (type I) we found only in the Catesbaeeae (sensu Delprete). Augusta longifolia (Spreng.) Rehd. has microrugulate orbicules (type II). Smooth and spherical orbicules smaller than 0.5 μm (type III) are most widespread in our sample of the Cinchonoideae. In Burttdavya nyasica Hoyle, they are irregular and folded (type IV). For each species a description is given of the orbicule and of the sexine morphology, to allow comparison. Species with spiny orbicules always have microspines on the pollen sexine. For the other orbicule types no such resemblance could be observed. Transmission electron microscope observations of four species are included to comment on ultrastructural differences between orbicule types. From this preliminary survey, we suggest that orbicule features in Cinchonoideae may be systematically useful on generic and tribal levels. Key words: Ubisch bodies, Rubiaceae, Cinchonoideae, orbicule ultrastructure, tapetum.

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.

The genera Corynanthe and Pausinystalia are an easily recognizable group within the tribe Coptosapelteae because the corolla lobes are provided with a distinct spherical, club-shaped or linear appendage. In the past the delimitation of the species and the 1–3 genera in the literature has been problematical. A short revision of the group is undertaken, based mainly on a study of Central African herbarium specimens. The morphological features of the group are reviewed and documented. Stipules were commonly found to have interlocking vernation; this type of ptyxis has not yet been reported from the Rubiaceae. Characters and their states are coded for a numerical phenetic and cladistic analysis of the relationships among the species. Our formal analyses corroborate the view that two genera can be recognized, Corynanthe (characterized by exserted style and anthers, undivided stigma and mainly loculicidal capsule; three species) and Pausinystalia (characterized by style and anthers included in the corolla tube, a bilobed stigma and predominantly septicidal capsule; five species). The entire group probably evolved from a Corynanthe-like ancestor; a drastic shift in flower biology, viz. the loss of secondary pollen presentation, probably correlated with adaptations to another pollinator which may have caused the divergence between the two genera. These show the characteristic distribution pattern of strict rain forest groups in Africa, except that they are missing from the lowland forests of the Zaire Basin. The species are concentrated around the known forest refugia of the quaternary glaciation: only C. pachyceras is distributed in almost the whole rain forest area. A formal taxonomic treatment (with key to species) of the two genera is given; a key to the genera of the Coptosapelteae of the African continent is also included. The examination of the isotypes of forgotten names described by the Berlin school revealed three new synonyms. Pausinystalia angolensis described from Cabinda (Angola) by Wernham is proved to be synonymous with P. macroceras. A few other taxonomic changes are made. Pausinystalia ituriense De Wild, is reduced to a subspecies of P. lane-poolei (Hutch.) Hutch, ex Lane-Poole; P. brachylhyrsum (K. Schum.) W. Brandt is recognized again (instead of being reduced to a form of P. macroceras (K Schum.) Pierre ex Beille), P. talbotii Wernham is maintained in Pausinystalia, and not transferred to Coiynanthe, as recently suggested.

The genera Corynanthe and Pausinystalia are an easily recognizable group within the tribe Coptosapelteae because the corolla lobes are provided with a distinct spherical, club-shaped or linear appendage. In the past the delimitation of the species and the 1–3 genera in the literature has been problematical. A short revision of the group is undertaken, based mainly on a study of Central African herbarium specimens. The morphological features of the group are reviewed and documented. Stipules were commonly found to have interlocking vernation; this type of ptyxis has not yet been reported from the Rubiaceae. Characters and their states are coded for a numerical phenetic and cladistic analysis of the relationships among the species. Our formal analyses corroborate the view that two genera can be recognized, Corynanthe (characterized by exserted style and anthers, undivided stigma and mainly loculicidal capsule; three species) and Pausinystalia (characterized by style and anthers included in the corolla tube, a bilobed stigma and predominantly septicidal capsule; five species). The entire group probably evolved from a Corynanthe -like ancestor; a drastic shift in flower biology, viz. the loss of secondary pollen presentation, probably correlated with adaptations to another pollinator which may have caused the divergence between the two genera. These show the characteristic distribution pattern of strict rain forest groups in Africa, except that they are missing from the lowland forests of the Zaire Basin. The species are concentrated around the known forest refugia of the quaternary glaciation: only C. pachyceras is distributed in almost the whole rain forest area. A formal taxonomic treatment (with key to species) of the two genera is given; a key to the genera of the Coptosapelteae of the African continent is also included. The examination of the isotypes of forgotten names described by the Berlin school revealed three new synonyms. Pausinystalia angolensis described from Cabinda (Angola) by Wernham is proved to be synonymous with P. macroceras . A few other taxonomic changes are made. Pausinystalia ituriense De Wild. is reduced to a subspecies of P. lane-poolei (Hutch.) Hutch. ex Lane-Poole; P. brachythyrsum (K. Schum.) W. Brandt is recognized again (instead of being reduced to a form of P. macroceras (K. Schum.) Pierre ex Beille). P. talbotii Wernham is maintained in Pausinystalia , and not transferred to Corynanthe , as recently suggested.

We studied the nectar characteristics in relation to flower age of the summer flowering Mediterranean shrubCapparis spinosa in three localities in Southern Greece. Anthesis was nocturnal. Nectar volume, concentration, and sucrose/hexose ratio varied with site, year, and between individual plants; amino acid concentration varied only with site. The sucrose/hexose ratio decreased considerably with flower age, while the glucose/fructose ratio remained constant (ca. 1), implying that nectar sucrose broke down in the course of anthesis. Sugar breakdown increased with water content of nectar. Amino acid concentration was strongly age-dependent: It was low in fresh flowers, relatively high in middle-aged ones (except aspartic acid that was extremely increased), and very high in senescent ones. We attribute the amino acid changes to phenomena related to flower senescence in the dark.

SUMMARY The floral ontogeny of Neurada procumbens L. has been investigated to clarify the position of the family Neuradaceae and to elucidate a number of morphological problems, such as the nature of the epicalyx and the 10-carpellate gynoecium. Morphological and ontogenetic evidence suggests a close affinity with the Rosaceae, contrary to reports of rbcL sequence data. There is a strong gynoecial resemblance with Maloideae, but other characteristics suggest that the affinities of Neuradaceae lie at the base of the Rosaceae.

The floral development of Coris was investigated to clarify its controversial relationship with either Primulaceae (Primulales) or Lythraceae (Myrtales). We demonstrate that Coris is strongly related to the Primulaceae but differs in a few important features, such as the presence of an epicalyx and partial zygomorphy. The saccate calyx and epicalyx with unilateral development encloses an actinomorphic flower. The stamen–petal tube has two sections that arise through three growth processes: a lower common part for stamens and petals and an upper section representing a fused corolla. The central ovule-bearing part of the ovary arises separated from the carpel wall. The formation of ridges with teethlike appendages between the ovules suggests a derivation of the free-central placentation from an axile arrangement. Several characters support the monotypic family Coridaceae near the Primulaceae. Key words: Coridaceae, Primulaceae, Lythraceae, floral development, floral vasculature, epicalyx, free-central placentation, common primordium, zygomorphy.

The term merosity stands for the number of parts within whorls of floral organs, leaves, or stems. Trimery is considered to be a basic condition that arose through the cyclisation of a spiral flower. Pentamery is mostly derived from trimery by the repetitive fusion of two different whorls. Dimery is either directly derived from trimery, or through pentamery as an intermediate stage. Tetramery is linked with pentamery and should not be confused with dimery. Possible causes for a change in merosity are the reduction of the number of carpels and zygomorphy in flowers. Derivations of different merosities have important consequences for the arrangement of the androecium (the insertion of stamen whorls, their identifications, and their number). It is concluded that two main groups can be identified within the angiosperms: magnolialean and monocotyledonean taxa are mostly trimerous or dimerous; non-magnolialean dicots are mostly pentamerous or tetramerous.

Two characters, viz. oligomery and polymery, have been previously proposed to circumscribe the localization of the androecium. Their distribution is more or less correlated with two groups of taxa: polymery is found in Magnoliidae, Caryophyllidae, Liliatae and part of Hamamelidae; oligomery is found in Dilleniidae, Rosidae, part of Hamamelidae and Asteridae. Polymery can be described by a number of character states, which are presented in a semophyletical scheme. Spiral polyandry, i.e. a multistaminate and spiral androecium, represents the plesiomorphic condition for all Magnoliophytina and is restricted to the polymerous group. Cyclization, induced by an arrangement of the perianth in trimerous whorls and a fractioning of the continuous plastochron, leads to polycycly, i.e. an arrangement of the stamens in numerous cycles; the outer stamens are usually inserted as pairs or in alternation with the inner perianth parts. From this configuration reduction series in different groups result in androecia with a lower number of stamen whorls (such as tetracycly, tricycly, dicycly and (ob)monocycly). The transition from trimery to pentamery induces a derived stamen configuration by the merging of two tepaline whorls and the loss of some stamens. Further reductions accompanied evolution in trimerous flowers and led to conditions resembling diplostemony as observed in Caryophyllaceae, some Hamamelidaceae and Ranunculaceae. Secondary increases, as well as reductions of stamens within a whorl must be regarded as gradual variations of each character state. Different trends affecting the number and position of the stamens can globally be traced along different lines. Polymery is consistent with other floral characters, such as the nature of perianth, vasculature (axial and cortical systems) and merosity. The androecium of a number of families and their relationships are discussed.

A revised definition of complex polyandry is presented for the Magnoliatae. The differences between primary polyandry and secondary (complex) polyandry are clarified. Fascicled stamens are probably not primitive in Magnoliatae. Complex polyandry finds its origin by an increase of stamens in an oligandrous framework. Multiplications of stamens occur either on primary complex primordia, which follow the regular phyllotactic sequence in the flower, either on a girdling primordium (ringwall). The primary primordia may be fully developed before a secondary proliferation of stamens takes place or provide room for more stamens by a continuing growth process. This happens by the development of a staminal tube (e.g. Malvales) or by the growth of a hypanthium (e.g. Myrtales). A typical floral vasculature is developed concomitantly with complex polyandry. Stamen trunk bundles (stamen fascicle traces) are correlated with preformed complex primordia and the absence of a hypanthium. The inception of a ringwall is responsible for a higher complexity in vasculature and for obscuring the identity of the trunk bundles. The presence of a hypanthium does not permit trunk bundle formation because stamens develop on a limited section of the hypanthial slope. In that case the vasculature is characteristically represented by few large bundles linked with the perianth and the androecium. The distribution of complex polyandry is plotted on a Dahlgrenogram and presented in a table. The systematic relevance of complex polyandry is limited to the lower taxonomic (e.g. familial) levels.

This study examines the diversity and character transformations in pollen and orbicule morphology of Ebenaceae, with a focus on subfamily Ebenoideae (ca. 600 sp.). 62 specimens comprising all three genera of Ebenoideae (Diospyos, Euclea, Royena), were studied using LM and SEM. Bayesian phylogenetic analysis was performed on molecular sequence data to establish an evolutionary hypothesis that was then used as an evolutionary framework to identify synapomorphies and trace evolutionary trends of palynological data with Bayesian posterior mapping and principle component analyses (PCA). Ebenoideae pollen is generally shed as monads (permanent tetrads in two species), medium-sized, prolate-spheroidal to subprolate and tricolporate. A substantial amount of variation is found in pollen size, equatorial outline (lobate, subtriangular, circular and hexagonal) and sexine ornamentation type ((micro)rugulate, striate, granulate and gemmate). Moreover, orbicules were present on the inner locule wall in all specimens examined. Their abundance, degree of fusion with tapetal membrane and aggregation vary considerably. We can conclude that Ebenaceae pollen is more heterogeneous than previously assumed. We traced palynological synapomorphies for groups at different taxonomic levels: subfamily level (pollen size, pollen wall stratification and aperture morphology), generic level (size, equatorial outline and sexine ornamentation types) and subgeneric clades (size, ectocolpus morphology, equatorial outline and sexine ornamentation subtypes) respectively. The granular infratectum and the unique sculpturing pattern on the orbicule walls are the most discriminating pollen features for subfamily Ebenoideae. (c) 2008 Elsevier B.V. All rights reserved. ispartof: Review of palaeobotany and palynology vol:153 issue:3 pages:336-353 status: published

The floral development and vascular anatomy of Nitraria retusa were investigated in order to understand its characteristic androecium of 15 stamens and to clarify the systematic position of the genus relative to Zygophyllaceae. Sepals arise in a helical sequence and are relatively small at maturity. Petals are initiated almost simultaneously or in a rapid helical sequence. Five stamen primordia arise opposite the sepals. Next, two other antesepalous primordia are incepted centrifugally to the first primordia on the remaining receptacular surface. The outer stamens tend to be squeezed between the petals and upper stamens and appear to make up an antepetalous whorl of stamens. Three carpels arise from a low ringwall and grow into a hairy trilocular pistil. In each locule a single pendulous ovule is present. Disclike nectarial tissue is initiated in pits between the stamens and petals. Long trichomes develop on its surface. It is concluded that the androecium is linked with a haplostemonous condition because the stamens of each triplet develop on strictly localized sectors. The distinction between stamens arising on complex primordia and the inception of three independent units is explained by the "principle of variable proportions." The vasculature also tends to confirm that the outer stamen pairs belong to antesepalous triplets.

The mature flower ofHarungana madagascariensis (Choisy)Poir. has an androecium of five antipetalous fascicles, consisting of four stamens each. The stamen fascicles alternate with five indented nectary scales. A SEM-study of the floral development, as well as a study of the floral anatomy was carried out to understand whether the nectariferous scales represent staminodia or are receptacular in nature and consequently whether or not the androecium ofHarungana, and theClusiaceae in general, is originally diplostemonous. The five petals originate by the splitting of petal-stamen complexes. Next the upper part of each complex differentiates basipetally in four stamens. The stamens remain fascicled and are lifted on a long stalk at maturity. Five carpel primordia are initiated united in a low ringwall. The five nectary scales appear after carpel inception and develop an external morphology reminiscent of anthers. The floral anatomy reveals an independent origin of sepal median traces and common sepal lateral traces, free petal traces, stamen fascicle traces and alternating vascular tissue which supplies the nectaries. The petal-stamen complexes are the result of a retardation in petal inception, linked with the absorption of petal tissue into the stamen primordia. The development of the stamen fascicles is discussed; it is suggested that they are of a secondary nature and do not appear as a reduction from a multistaminate androecium. The external morphology and vascular anatomy of the scales speaks in favour of a staminodial nature. The comparison with some other species of theClusiaceae gives evidence of a diplostemonous ancestry of the androecium.

RONSE DECRAENE, L.-P. & SMETS, E., 1991. The impact of receptacular growth on polyandry in the Myrtales. The androecium of the Myrtales shows a wide variation in structure and development, linked with an original diplostemony. The difference between a centrifugal stamen inception in Lythraceae against a centripetal inception in other families has been a major issue in discussing the internal relationships of the Myrtales. The first stamens usually arise as pairs opposite the petals on primary androecial primordia. It is shown that the number of stamens that are initiated and the difference between the direction of development of more stamens are based on the extent of growth of the receptacle after the inception of the primary androecial primordia. In Lagerstroemia indica, receptacular growth takes place between stamens and petals providing room for a centrifugal development. In the Punicaceae and Myrtaceae growth of the receptacle occurs between the androecium and gynoecium, leading to a centripetal development of the stamens. The development of a ring-wall is discussed and a comparison is made with other types of complex polyandry.

A study of the floral ontogeny of Popowia was carried out to investigate the phyllotactic arrangement of the floral organs and occurring trends in the androecium of Annonaceae. The flower buds arise on a common stalk in the axil of a bract. Three sepals emerge in quick succession and are rapidly overrun in size by two whorls of petals. The androecium is initiated centripetally in successive whorls. A first whorl of three pairs of outer staminodes emerges opposite the outer petals and is followed by nine staminodes. Next a whorl of nine fertile stamens arises in alternation with the second whorl of staminodes. The carpels arise in three alternating whorls of nine. The nature of the perianth parts is morphologically identical. The process of cyclisation of the androecium from a spiral is discussed for Annonaceae and Magnoliidae in general. The inception of the three outer stamen pairs is a widespread reductive step for multistaminate androecia in the process of oligomerization. It is proposed to define the cyclic inception of numerous stamens as whorled polyandry, being an intermediate step between true polyandry and a reduced stamen number in whorls. The absence of a cup-like shape in the carpel development is related to the flattened receptacle.

• Background and Aims The generic delimitations of Ficinia and Isolepis, sister genera in the Cypereae, are blurred. Typical Ficinia flowers have a lobed gynophore, which envelops the base of the nutlet, whereas in Isolepis the character is considered to be absent. Some former species of Isolepis, lacking the gynophore, were recently included in Ficinia. The floral ontogeny of representative taxa in Ficinia and Isolepis were investigated with the aim of evaluating the origin and nature of the gynophore in the Cypereae. • Methods The spikelet and floral ontogeny in inflorescences collected in the field was investigated using scanning electron microscopy (SEM) and light microscopy (LM). • Key Results SEM images of Isolepis setacea and I. antarctica, Ficinia brevifolia, F. minutiflora, F. zeyheri and F. gracilis, and LM sections of F. radiata, show that the gynoecium in Ficinia is elevated above the flower receptacle by the development of a hypogynous stalk. From its apex, a (often three-)lobed cup is formed, which envelopes the basal part of the later nutlet. In developing flowers of I. antarctica, a rudimentary hypogynous stalk appears. In I. setacea, rudiments of a hypogynous stalk can be observed at maturity. In F. radiata and F. zeyheri, intralocular hairs are present in the micropylar zone. At the surface of developing gynoecia in flowers of F. gracilis, star-shaped cuticular structures appear which disappear again at maturity. • Conclusions The overall floral ontogeny of all species studied occurs following a typical scirpoid pattern, though no perianth primordia are formed. The gynophore in Ficinia originates as a hypogynous stalk, from which the typical gynophore lobes develop. The gynophore is not homologous with the perianth.

The infrafamilial relationships of the Gentianaceae are investigated by means of a cladistics analysis of 84 phenotypic characers, based mainly on data from the literature. The 41 genera that were selected for the analysis, including the formerly loganiaceous genera Anthocleista and Fagraea and the monotypic genus Saccifolium, are a fair representation of the character diversity in the family. The diverse genus Gentiana is represented by six of its sections. As outgroups we used Strychnos and Geniostoma (Loganiaceae), Gelsemium (Gelsemiaceae), and two genera each of Apocynaceae and Rubiaceae. In the strict consensus cladogram of all most-parsimonious trees Gentianaceae has an unresolved basal trichotomy between Saccifolium (of tribe Saccifolieae), Potaliinae, and a major clade including all other genera. In this clade only tribe Gentianeae and subtribe Chironiinae of tribe Chironieae (Ixanthus excepted) are recocgnized as monophyletic gro ups. Within tribe Gentianeae, subtribe Gentianinae is nested in paraphyletic tribe Swertiinae. The relationships between the representatives of Exaceae, Canscorinae and Coutoub einae (Chironieae), and Helieae are almost completely unresolved. An interesting exception is the sister-group relationship between Exacum and Cotylanthera. Two complementary explanations for the lack of resolution in most parts of the cladogram are discussed: (1) the morphological characters of most tropical members of the family are insufficiently known, and (2) morphological characters are not well suited to resolve the more basal relationships in Gentianaceae. ispartof: Gentianaceae: systematics and natural history pages:310-376 ispartof: pages:310-376 status: published

Modern pollen precipitation studies were carried out on a regional scale in the territory of the classical city of Sagalassos (Southwest Turkey). 57 moss cushions and 7 soil samples from different vegetation types were analysed palynologically. The resulting pollen spectra were grouped into 14 vegetation groups, which were examined using discriminant analysis and principal components analysis. These numerical procedures are applied to display the structure in the data set in a comprehensive way. Some of the modern spectra groups seem to be well-defined, whereas others are difficult to distinguish from each other. After the relationships between the modern pollen spectra had been analysed, the fossil data from a core from the marsh of Gravgaz were added to the data set so that any similarities between fossil and modern spectra could be seen. A joint principal components analysis of the modern and fossil pollen spectra revealed that the pollen spectra from the earliest (ca. 2600-2500 BP; Cal. 830-590 BC till 790-520 BC) and the latest (starting at ca. 1300 BP; Cal. 660-780 AD) pollen assemblage zones have modern counterparts. On the other hand, the pollen spectra from the pollen assemblage zone dominated by Artemisia (ca. 2500-2300 BP; Cal. 790-520 BC till 410-210 BC) and from the pollen assemblage zone that indicated the practice of arboriculture (ca. 2300-1300 BP; Cal. 410-210 BC till 660-780 AD) have no close modern analogues, although individual tabulated pollen percentages revealed some similarities with some modern spectra groups.

De 1992 a 1994 nous avons etudie la secretion nectarifere (volume, concentration, teneur en sucres) des fleurs de 76 especes nectariferes d'une communaute vegetale de type garrigue («phrygana») situee pres d'Athenes, Grece. Ces valeurs ont ete mises en relation avec le nombre de plantes en fleurs et les caracteristiques de la fleur, donnees mesurees au champ ou tirees de la litterature. Toutes les mesures et les valeurs calculees sont donnees dans les tableaux 1 et II. On a preleve le nectar de fleurs encagees de 1 j a l'aide de microcapillaires de 0,1-10 μl pour en determiner le volume et mesure la concentration en sucres avec un refractometre a main. Les valeurs moyennes ont ete respectivement de 0,77 μl et 55,1 % (en rapport de poids). A partir de ces valeurs on a calcule la teneur absolue en sucres par fleur. Pour un petit nombre d'especes qui fournissaient tres peu de nectar, cette valeur a ete obtenue par une analyse des sucres par chromatographie liquide a haute pression (HPLC) au laboratoire; pour ce faire, le nectar floral a ete recolte au champ sur des meches de papier, qui ont ete sechees et conservees jusqu'au moment de l'analyse. La teneur moyenne en sucres par fleur des 76 especes a ete de 0,44 mg. La date moyenne de floraison n'est correlee avec aucune des 3 caracteristiques du nectar. Une correlation negative a ete trouvee entre la profondeur de la fleur et la concentration en nectar. Il existe des differences en fonction de la famille botanique, de l'appartenance a une forme de vie (geophyte, herbacee perenne, ligneuse perenne therophyte), de la profondeur ou de la forme de la fleur. Le tableau III donne les resultats de l'ANOVA pour ces 4 parametres, ainsi que les tests a posteriori faisant intervenir la «correction de Bonferoni»: les Labiees sont de loin les especes de la communaute les plus riches en nectar, a la fois en volume et en teneur en sucres. Elles se distinguent significativement des Composees. Les therophytes produisent significativement moins de nectar et/ou de sucre que les plantes herbacees perennes. Les especes dont les fleurs ont une profondeur > 4 mm produisent plus de nectar que les fleurs peu profondes, mais cela ne conduit pas a une plus forte teneur en sucres a cause de leur concentration significativement plus faible. En ce qui concerne la forme, les fleurs en forme de sac sont de loin les meilleures productrices de nectar et/ou sucre, bien qu'ayant une concentration moindre que les fleurs en forme de disque, mais ceci est probablement une consequence de leur position taxonomique. Les donnees mentionnees ci-dessus nous permettent d'estimer le potentiel mellifere de la «phrygana» aussi bien que d'autres formations vegetales mediterraneennes de meme type. Le potentiel mellifere par ha de la communaute etudiee a ete estime a 455 g de sucres (n = 76), ou 307 g si l'on ne prend en compte que les plantes visitees par les abeilles melliferes, ce qui correspond en gros a 535 et 360 g de miel respectivement. Mais ces valeurs sont certainement sous-estimees en raison de la methode employee. Nous esperons que ces resultats contripollinisatrice indigene et a un meilleur amenagement des regions concernees. De ce point de vue nous insistons particulierement sur le fait que ces ecosystemes devraient etre exploites avec precaution au cours des annees qui suivent les incendies, puisque la production de nectar est alors plus faible que celle d'un systeme pleinement developpe. Dans les cas ou le nectar est en quantite limitee, les abeilles solitaires, qui sont les pollinisateurs indigenes de ce systeme, pourraient etre menacees d'extinction par l'efficacite de butinage et les meilleurs performances de l'abeille domestique

Four different evolutionary lines can be recognised for the androecium of the Ranunculiflorae: (1) a progressive reduction in the number of stamens and stamen whorls. (2) The transformation of the outermost stamens into nectar-leaves or petals. (3) Meristic changes of the flower. (4) Secondary increases in the number of stamens. It is shown that the position and inception of the stamens is valuable to understand relationships of taxa. Ranunculaceae occupy a basal position with the greatest androecial diversity and a reductive trend, linked with a shift from trimery to pentamery and the transformation of the outer stamen pairs into (nectariferous) petals. Berberidaceae and satellite families have androecia with an alternation of trimerous (dimerous) whorls and outer staminodial nectar-leaves. In Papaverales the trimerous flower with a polycyclic androecium often becomes dimerous and is progressively reduced. Secondary increases occur occasionally in Berberidaceae, Papaveraceae and perhaps Glaucidiaceae.

In the system of classification sensu Cronquist, the division between the two subclasses Dilleniidae and Rosidae relies on only a few characters. The major distinguishing character is the occurrence of centripetal or centrifugal sequence of stamen development. We question not only the application and the value of this character, but also the maintenance of the Rosidae and Dilleniidae as separately derived natural taxa, because of the lack of solid distinguishing criteria. We have studied the staminal characters in the 192 families of the Dilleniidae and the Rosidae, using Dahlgren's classification diagram. The study focussed on the following androecial characters: 1) polyandry; i.e. spiral polyandry, complex polyandry (viz. centrifugal, centripetal and lateral polyandry) and cyclic polyandry 2) diplostemony and obdiplostemony 3) haplostemony and obhaplostemony. In our proposal only two characters are maintained, namely oligomery (diplostemony s.l.) and polymery (true polyandry s.l.), both having a number of character states. Polyandry, as it has been described up to now, is not to be regarded as homologous in all Magnoliophytina. Both characters correspond to two different lines within the Magnoliatae. In addition, the division between the Dilleniidae and Rosidae sensu Cronquist is no longer tenable. Finally, a number of modifications of Dahlgren's diagram are suggested and a division of the Magnoliophytina in a polymerous group and an oligomerous group is proposed. The Dilleniidae-Rosidae complex is included in the oligomerous group.

The genus Fuirena Rottb. is currently classified in the tribe Fuireneae Reichenbach ex Fenzl (subfamily Cyperoideae), based on the presence of spikelets with many spirally arranged glumes, each subtending a bisexual flower, and because of unique embryo characters. The trimerous Fuirena flowers have two whorls of perianth parts that show a wide morphological variety and various reduction trends. In flowers of F. ciliaris (L.) Roxb., the outer whorl consists of three bristle-like perianth parts opposite the stamens. The three scale-like inner perianth parts alternate with the stamens. The nature and exact position of the inner perianth parts have long been a subject for discussion. In the context of the 'synanthium' hypothesis, some authors have interpreted the perianth parts as floral bracts. Alternatively, the inner perianth parts have also been interpreted as staminodia because of their appearance and position. In this study we present new evidence in favour of a conventional monocotyledonous pentacyclic flower model in Cyperoideae based on SEM observations on the floral ontogeny of F. ciliaris, F. leptostachya Oliver, F. abnormalis C.B.Clarke and F. pubescens (Poir.) Kunth. Our observations confirm a pentacyclic organisation of the flowers within Fuirena, and they corroborate the interpretation of the inner scales and outer bristles as perianth parts.

Pyrene and pollen morphology of several neo- and paleotropical Geophila species is documented and discussed. Pyrenes show distinct morphological variation. They have one central or several adaxial ribs and are straight or twisted. Neotropical species only have twisted pyrenes, whereas Madagascan species have straight ones. Both pyrene types occur on the tropical African mainland and in tropical Asia. The genus is eurypalynous, including inaperturate, colpate and pantoporate pollen. The paper includes the first record of operculate pollen in the Rubiaceae, viz. in Geophila repens var. repens. Pyrenes as well as pollen morphology indicate that the varieties of the pantropical species G. repens need recognition at the specific level.

The pollen morphology and distribution of orbicules were investigated in ten species of the genus Coptosapelta (Rubiaceae) using light, scanning electron and transmission electron microscopy. In general, Coptosapelta pollen is three- to five-pororate and suboblate to oblate-spheroidal. The sexine ornamentation varies from psilate to reticulate, and the pollen-wall stratification lacks columellae. 'Droplets' are observed on the inner nexine surface. Distinct orbicules are found in five species. Orbicules are often lobed and appear to be aggregated and embedded in the tapetal remnants of the locule wall. Ultrastructurally, a single, flattened core is frequently observed. Coptosapelta has a unique pollen type within Rubiaceae and does not resemble possibly related genera. Pollen characteristics provide additional evidence supporting earlier findings that Coptosapelta represents an isolated lineage in Rubiaceae.

The floral ontogeny of four species of Phytolacca (P. acinosa, P. clavigera, P. dodecandra, and P. americana) shows major differences in the number and position of stamens and carpels. Five sepals are always formed in a 2/5 sequence. The number of stamens is mostly eight, with a sequential initiation: six outer stamens are arranged in three pairs opposite sepals 1-3; single stamens stand opposite sepals 4-5, except for P. americana, where all antesepalous stamens are positioned in pairs (10 stamens rather than eight). The stamens of the first, second, and third pair arise simultaneously as independent entities. The stamens of the third pair occasionally arise sequentially and are displaced in relation to the third sepal. Stamens opposite sepals 4 and 5 follow sequentially. The delayed plastochron of the stamens opposite sepal 3 indicates that the pentamerous flower has been derived from a trimerous precursor. Phytolacca dodecandra has 10 stamens arising in a different sequence: the five inner stamens are ...