Fruits and seeds of Ruppia (Potamogetonaceae) from the Pliocene of Yushe Basin, Shanxi, northern China and their ecological implications

Numerous fruits and seeds of Ruppia are reported from the Upper Pliocene (2.3–3.5 Myr ago) Zhangcun Formation in Yushe Basin, Shanxi, northern China. They are the first fossil Ruppia from China and demonstrate the importance of fruit and seed fossils in recording genera not represented by fossil leaves. These Ruppia are characterized by possessing a small oval endocarp, smooth endocarp surface, distinct elliptical external depressions, distinct apical mucro, slightly curved seed shape and conspicuous globose hilum. A new species, R. yushensis Zhao, Collinson and Li, is described from these endocarp and seed features. Comparison with the two European Miocene species, R. palaeomaritima Negru and R. maritime-miocenica Szafer, indicates the existence at that time of three different geographical and stratigraphical species. R. yushensis constitutes the first Pliocene record of Ruppia and extends the range of fossils of this genus from Europe to eastern Asia. R. yushensis is the only aquatic plant in the uppermost middle part of the Zhangcun Formation. This monotypic occurrence indicates a brackish, clear, tranquil and shallow lake in this region in the Late Pliocene. The smooth endocarp surface further suggests a warm temperate or temperate palaeoclimate.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 145 , 317–329.     

Curtisia (Cornales) from the Eocene of Europe and its phytogeographical significance

Fossil remains of Curtisia Aiton (Cornales) are recognized for the first time from the Tertiary of Europe, based on early Eocene anatomically preserved fruits from the London Clay and Poole Formations of southern England. The modern distribution of this monotypic genus is limited to the cape of South Africa. Curtisia quadrilocularis (Reid & Chandler) comb. nov. fruits have globose tetralocular endocarps composed of isodiametric sclereids with a single seed per locule, a prominent axial vascular canal, apical placentation, and four germination valves. All of these characters, as well as size, correspond to extant Curtisia . Although many fossil taxa from the Eocene of Europe have been shown to have their closest extant relatives in Asia, this occurrence of Curtisia highlights Tertiary floristic exchange between Europe and Africa. The newly recognized fossil occurrences suggest a Laurasian origin for Curtisia , in conformity with the fossil record for several other genera of the Cornales. In addition, our rejection of the former assignment of this species to Leucopogon causes us to question whether Epacridaceae were present in the Tertiary of Europe.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 127–134.     

Molecular and morphological data reveal cryptic taxonomic diversity in the terrestrial slug complex Arion subfuscus/fuscus (Mollusca, Pulmonata, Arionidae) in continental north-west Europe

The importance and abundance of cryptic species among invertebrate taxa is well documented. Nowadays, taxonomic, phylogenetic and conservation biological studies frequently use molecular markers to delineate cryptic taxa. Such studies, however, often face the problem of the differential resolution of the molecular markers and techniques involved. This issue is explored in the present study of cryptic taxa within the terrestrial slug complex Arion subfuscus/fuscus in continental north-west Europe. To this end, morphological, allozyme and mitochondrial 16S rDNA sequence data have been jointly evaluated. Using allozyme data and gonad type, two distinct groups were consistently delineated, even under sympatric conditions. The 16S rDNA data strongly supported both those groups and even suggested the presence of three distinct taxa within one of them. However, in view of: (1) the allopatric distribution of three OTUs, (2) the lack of allozyme or morphological differentiation, and (3) the extremely high degree of intraspecific mtDNA variation reported in pulmonate gastropods, they are, for the time being, not regarded as valid species under the biological species concept. By means of 16S rDNA and allozyme data, the position of type and topotype material of A. subfuscus s.s. and A. fuscus relative to the newly defined OTUs was determined, thus clarifying the nomenclature of this species complex. Additionally, gonad type proved to be a useful character for distinguishing the two species in north-west Europe.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 83 , 23–38.     

The ecological status of the carob-tree (Ceratonia siliqua, Leguminosae) in the Mediterranean

The present distribution of the carob-tree ( Ceratonia siliqua L.) throughout the coastal regions of the Mediterranean, the route followed from its possible place of origin in southern Arabia and the Horn of Africa, and the possible circumstances of the tree's domestication are discussed in the light of botanical, archaeological, historical and philological evidence. It is shown that the genus Ceratonia formed part of the wild flora of western Europe in preglacial times, that C. siliqua was present in ancient times in the Middle East and that its spread to the western Mediterranean area took place progressively, possibly beginning in the second millennium bc . From the fact that, except in the case of Greece and southern Italy, most of the names applied to the tree today in European languages are linked to Arabic, it is inferred that today's cultivars were probably selected by Muslims in the Middle Ages.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 431–436.     

Karyomorphology of Incarvillea (Bignoniaceae) and its implications in distribution and taxonomy

The karyomorphology of 11 species of the genus Incarvillea Juss. is reported. The chromosome numbers of all species studied are 2 n  = 22. The interphase nuclei and prophase chromosomes were found to be of the simple chromocentre type and the interstitial type, respectively. The asymmetry of the karyotype of I. arguta (two populations) in subgenus Amphicome is type 2A. The karyotypes of Incarvillea s inensis var. sinensis , I.  s inensis var. przewalskii, and I. olgae in subgenus Incarvillea are of asymmetry type 3A. The remaining nine species and one variety in subgenus Pteroscleris are also of asymmetry 3A. Data on three species and one variety studied are first reports. This study indicates that karyotype variation at the diploid level appears to be the predominant feature of chromosome evolution in the genus Incarvillea . According to this study of karyomorphology, morphological characteristics and geographical distribution, it seems that the three subgenera should be regarded as three independent genera. The geography of the genus is discussed.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 113–121.     

Revision of Trigonostomum Schmidt, 1852 (Platyhelminthes, Typhloplanoida, Trigonostomidae) with the description of seven new species

A morphological and taxonomic account of the genus Trigonostomum is provided. All known species are discussed and briefly re-described where necessary. Seven new species are described: T. franki from Curaçao, Florida (USA), the East African Coast and New Caledonia, T. nataschae from the French sub-Antarctic island Kerguelen, T. spinigerum from New Caledonia and T. watsoni from the Australian East Coast and New Caledonia. T. tori and T. galapagoensis , both formerly enclosed in T. setigerum , are considered new species, while T. australis also belongs to the same species group. Proxenetes denhartogi is transferred to Trigonostomum . Based on a comparison of old and new material, T. marki is synonymized with T. penicillatum , while T. prytherchi and T. divae are regarded as junior synonyms of T. lilliei ; T. intermedium and T. quadrifolium are considered synonyms of T. coronatum . Three species are considered species inquirendae : T. brunchorsti , T. piriforme and Marinellia lingulifera . Similarities and differences of the 17 valid species are discussed and summarized in an identification key.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 141 , 271–296.     

A new endemic species of Epipactis (Orchidaceae) from north-east Portugal

A new species, Epipactis duriensis Bernardos, D. Tyteca, Revuelta & Amich is described and illustrated from north-east Portugal. Notes on its distribution, ecology, karyology, micromorphology and taxonomic relationships are presented as well as molecular data based on ITS analysis. A list of diagnostic differences between E. duriensis and the closely related species E. lusitanica and E. tremolsii is provided.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 145 , 239–249.     

A new Spanish species of Tragopogon (Asteraceae: Lactuceae)

Tragopogon cazorlanum (Asteraceae: Lactuceae) is proposed as a new Spanish species with distribution restricted to the Baetic mountains (south-eastern Spain). Its morphological, palynological, chromosomal, biogeographical and ecological features are discussed, as well as its main relationships and differences with reference to other Spanish species of the genus.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 505–511.     

A new species of Nigella (Ranunculaceae) from Turkey

Nigella turcica a new species endemic to north-eastern Turkey is described and illustrated. Morphological differences between the species and the closely related species, N. sativa , are discussed and the IUCN threatened category is proposed. A distribution map of the new species and its related taxon is given.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 251–255.     

A new species of Arabis (Brassicaceae) from inner Anatolia

A new species of Arabis L., A. erikii Mutlu sp. nov. , is described and illustrated. The species is restricted to inner Anatolia, south-west of Sivas. It grows on steppes. Diagnostic morphological characters are given for discrimination from the most similar taxa.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 145 , 251–256.     

Genetic structure and morphological variation of British populations of the hybrid Potamogeton x salicifolius

Potamogeton x salicifolius Wolfg. is one of the three most frequently recorded Potamogeton hybrids in the British Isles and Europe. It is thought to be the hybrid between P. lucens and P. perfoliatus. Its scattered distribution suggests that it has arisen several times in Britain. Most British populations of P. x salicifolius can be identified by their morphological characteristics, which are intermediate between those of the putative parents P. lucens and P. perfoliatus . However, the population at the Ouse Washes, Cambridgeshire, differs from other populations in its greater similarity to P . lucens . A genetic study of eight British populations, using six isozyme systems, revealed that most populations consist of a single multi-enzyme phenotype. This suggests that they were the result of a single hybridization event and are therefore maintained through vegetative reproduction. By contrast, the Ouse Washes population consists of three multi-enzyme phenotypes. This variation is likely to have resulted from multiple hybridization events, although we cannot exclude the possibility that the plants are partially fertile. The isozyme systems studied were unable to identify P. lucens and P. perfoliatus unambiguously, and consequently did not provide evidence for their putative parentage of P. x salicifolius. However, at a local level the banding patterns of the hybrids were generally consistent with the local multi-enzyme phenotypes of these putative parents.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 99–111.     

Little genetic differentiation across Europe between early-flowering and late-flowering populations of the rapidly declining orchid Neotinea ustulata

Amplified fragment length polymorphism (AFLP) was used to characterize genetic diversity of the endangered Burnt Orchid, Neotinea (formerly Orchis ) ustulata . Fingerprinting of Estonian and British populations revealed surprisingly little genetic differentiation between populations but larger amounts of diversity within populations, especially in Britain. The resulting mean F _st value of 0.51 is unusually high for an orchid species. Much of the variation follows a west–east cline across Europe, whereas the much-discussed early- and late-flowering taxa of N. ustulata are considered insufficiently distinct to be viewed as separate subspecies. The later flowering N. ustulata var. aestivalis probably evolved independently on two or three occasions, each time diverging from the earlier flowering nominate race. The identity of the genes underpinning phenology in the species, and the potential selective advantages of phenological divergence, merit further study. Overall genetic diversity within populations is sufficiently high to render impoverishment an unlikely cause of their recent, precipitous decline.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 13–25.     

Distribution, phenology and demography of sympatric sexual and asexual dandelions (Taraxacum officinale s.l.): geographic parthenogenesis on a small scale

In many plant and animal species, sexual and asexual forms have different geographical distributions ('geographic parthenogenesis'). The common dandelion Taraxacum officinale s.l. provides a particularly clear example of differing distributions: diploid sexuals are restricted to southern and central Europe, while triploid asexuals occur across Europe. To get a better understanding of the factors underlying this pattern, we studied the distribution and demography of sexuals and asexuals in a mixed population that was located at the northern distribution limit of the sexuals. In this population three adjacent, contrasting microhabitats were found: a foreland and south and north slopes of a river dike. Comparative analyses of the distribution, phenology and demography indicated that sexuals had a stronger preference for the south slope than did asexuals. We therefore propose that the large-scale geographic parthenogenesis in T. officinale is shaped by an environmental gradient which acts upon the sexuals.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 82 , 205–218.     

Fitness of insularia morphs of the peppered moth Biston betularia

In recent years the industrial melanic carbonaria morph in the moth Biston betularia (L.) has decreased rapidly in frequency in Britain as air pollution has decreased. The intermediate melanic insularia has shown a variable response. We have estimated the fitness of insularia, compared with the other two morphs, for several data sets. As a rule its fitness lies between that of carbonaria and typical, but nearer to typical and sometimes very close to it. The intermediate position is expected if fitness relates directly to phenotype. The results suggest that insularia may continue polymorphic while carbonaria is likely to disappear. The past high frequency of insularia in South Wales may have been due to an initial increase in insularia frequency before carbonaria reached the region. Differences in dynamics of frequency change in insularia and carbonaria are evidence against induction, which has sometimes been invoked to explain the spread of melanism in this species.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 82 , 359–366.     

A new species of Exostyles (Leguminosae, Papilionoideae, Swartzieae s.l.), from Paraná State, Brazil

A new species Exostyles godoyensis Soares-Silva & Mansano (Leguminosae, Papilionoideae, Swartzieae), endemic to Paraná state in southern Brazil, is described and illustrated. The new species is distinct from all the other species of Exostyles in having a leaf with up to five leaflets, while the other species have at least seven leaflets per leaf. The new species is distinct from Exostyles amazonica Yakovlev in its longer stamen filaments and ovary stipe and from E. glabra Vogel and E. venusta Schott by its shorter anthers. In addition to these morphological characters E. godoyensis has a disjunct geographical distribution.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 103–106.