Achene anatomy and stomatal characteristics of eighteen Crepis L. (Asteraceae) taxa from Turkey with notes on their systematic significance

Achene anatomy and stomatal characteristics of eighteen Crepis taxa from Turkey are here described for the first time. In all taxa examined the pericarp is composed of several layers of sclerenchymatous and parenchymatous cells. As for the achene, differences among taxa mainly concern the pericarp structure and its thickness and width. Stomata are present on both surface of the leaf in all studied taxa and all taxa have anomocytic type stomata. However, the dimensions (length and width) and density of the stomata differ significantly among the studied taxa. In addition, the dimensions of stomata are negatively correlated with stomata density. It is concluded that achene anatomy and stomatal characteristics are useful for delimitation of Crepis taxa and a key to taxa based on these characters is provided. However, based on achene anatomy and stomatal characteristics, we found no argument for an exclusion of the Lagoseris group from Crepis as has previously been proposed.     

NITZSCHIA ALICAE SP. NOV. AND N. PURIFORMIS SP. NOV., NEW DIATOMS FROM EUROPEAN RIVERS AND COMPARISON WITH THE TYPE MATERIAL OF N. SUBLINEARIS AND N. PURA1

Nitzschia sublinearis Hustedt and N. pura Hustedt are common oligosaprobic freshwater diatom species that frequently occur in diatom inventories, thus being important in water quality studies. Both are considered as species with overlapping diagnostic criteria in several floras, which is typical of the whole genus Nitzschia. The type material of Hustedt of N. sublinearis and N. pura was examined using LM and EM in order to document the range of variation within the type populations and to compare it with populations occurring in different European rivers. Detailed observations allowed recognition of two new freshwater diatom species: N. alicae sp. nov., occurring in mesotrophic up to eutrophic conditions, and N. puriformis sp. nov., mostly occurring in oligotrophic habitats, both in rivers and streams at middle and high altitudes. The most reliable taxonomic features that separate both new species from the most similar taxa are the density of fibulae and striae, valve shape, and valve width as well as the shape of areolae. Morphological examination of different populations indicates that N. puriformis is relatively common in European rivers and has been overlooked to date and confounded with N. pura by several researchers. By contrast, N. alicae has, to date, been collected only in Slovakia and Northern Italy, but with a high frequency of occurrence and sometimes in high abundance at sites.     

PINUXYLON WOOLARDII SP. NOV., A NEW PETRIFIED TAXON OF PINACEAE FROM THE MIOCENE BASALTS OF EASTERN OREGON

Specimens of the new species Pinuxylon woolardii have been collected from Miocene strata near Durkee, OR. These petrified specimens are unique in that, due to weathering, individual tracheids and ray cells can be separated for detailed SEM studies. This species is characterized by its high number of ray cells; numerous rays; large resin ducts which are commonly paired; primarily uniseriate pitting, two to five (usually three) small, oval or circular pinoid pits per crossfield; and smooth walls on its transverse (ray) tracheids. The latter character relates this species to taxa in the subgenus Haploxylon of Pinus. Pinuxylon woolardii is most similar to the fossil species Pinuxylon parryoides and the extant species Pinus aristata, P. cembroides, P. edulis, P. monophylla and P. balfouriana. These modern species live in dryer environments and at higher elevations than that suggested by the Miocene leaf floras which occur near the locality of P. woolardii.     

PSEUDOFAGUS IDAHOENSIS,N. GEN. ET SP. (FAGACEAE) FROM THE MIOCENE CLARKIA FLORA OF IDAHO

A new genus and species of Fagaceae are established for compressed leaves and attached fruits which represent one of the dominant taxa in the rich Miocene Clarkia flora of northern Idaho. The leaf and fruit morphology, cuticular and pericarp anatomy, and leaf phytoliths fall within the range of variation of the subfamily Fagoideae. The unique fruit consists of a large, exposed, distinctly keeled, trigonous nut and a diminutive basal cupule. The cupule has an apical frill of free, petiolate, leaflike appendages but lacks other ornamentation, and there is no evidence of a distinct Valvation. As no other genus of the Fagaceae has fruits with this combination of characters, a new genus is established and is referred to the subfamily Fagoideae. The Miocene genus seems most closely related to the extant genus Fagus.     

Anamorphic fungi from freshwater habitats in China: Dictyosporium tetrasporum and Exserticlava yunnanensis spp. nov., and two new records for Pseudofuscophialis lignicola and Pseudobotrytis terrestris

This article describes two new anamorphic fungi from freshwater habitats, Dictyosporium tetrasporum sp. nov. and Exserticlava yunnanensis sp. nov., based on morphological characters. Both species are illustrated with light micrographs and compared with similar taxa. Pseudofuscophialis lignicola and Pseudobotrytis terrestris are reported as new records from freshwater habitats.     

Hesperogavialis cruxenti N.Gen., N. SP., nouveau Gavialide (Crocodylia,Eusuchia) du Miocene superieur (Huayquerien) d'Urumaco (Venezuela)

A new gavialid from the Upper Miocene (“Huayquerian”) of Urumaco (western Venezuela) is described as Hesperogavialis cruxenti n. gen., n. sp. It is the only known South American gavialid in which, as in the Gavialidae from the Indian region, the nasals do not come into contact with the premaxillae. This ressemblance with the gavials of India is interpreted as a result of convergent evolution.     

A New Rhinoceros, Victoriaceros kenyensis gen. et sp. nov., and Other Perissodactyla from the Middle Miocene of Maboko, Kenya

The middle Miocene site of Maboko (Lake Victoria, Kenya), dated to ca. 15 Ma, has yielded one of the best collection of rhinos in Africa. The most common taxon, Victoriaceros kenyensis n.gen., n.sp., is represented by an almost perfect skull (whose main features are the large nasal horn, an orbit located very anteriorly and with a prominent border, and very broad zygomatic arches) and numerous limb bones, probably belonging to only a few individuals. Characters of the teeth and skull support an assignment to the subfamily Elasmotheriinae, a group best known in the middle and upper Miocene, but whose monophyly is disputable, as some of their tooth characters could be adaptations to a grazing diet (in agreement with their distribution in the Maboko beds). In any case, Victoriaceros clearly differs from other East African middle Miocene rhinos, whose diversity is far greater than currently assumed. A few other specimens attest to the occurrence at Maboko of at least one other species, perhaps close to the brachypotheres; a single calcaneum is tentatively assigned to the Chalicotheriidae.     

ETAPTERIS LECLERCQII SP. N., A ZYGOPTERID FERN FROM THE PENNSYLVANIAN OF NORTH AMERICA

The zygopterid fern Etapteris leclercqii sp. n. is described from Lower Pennsylvanian age coal balls from the Lewis Creek, Kentucky, locality. Isolated petioles extend up to 15.0 cm in length and 5.0 mm in diam; no lateral axes have been observed. The clepsydroid-shaped petiole trace is characterized by lateral arms that sharply taper and by the production of peripheral loops prior to the separation of pinna traces from the stele. Large irregularly shaped multicellular hairs are randomly scattered over the surface of the petioles. When compared with other currently recognized zygopterid ferns, E. leclercqii appears most similar to Metaclepsydropsis duplex. Based on the configuration of the leaf trace and the occurrence of peripheral loops, it is suggested that E. leclercqii may represent the most primitive species of the genus known to date.     

RADIOSPHAERA NEGEVENSIS SP. N., A NEW CHLOROCOCCALEAN DESERT ALGA

Radiosphaera negevensis n. sp. f. negevensis and f. minor f.n. were isolated in culture from a surface growth of algae on desert soil and subsequently found in other desertic habitats. The characteristics which distinguish between the genera Radiosphaera and Actinochloris are discussed.     

Significance of achene characteristics and within-achene resource allocation in the germination strategy of tetraploid Aster pilosus var. pilosus (Asteraceae)

The interrelationships among achene weight, allocation to embryo and pericarp, and germination time were determined for 500 stratified achenes of tetraploid Aster pilosus Willd. var. pilosus. Only 52.6% of the achenes germinated. Germinated achenes were significantly heavier than ungerminated achenes. Germination time was independent of achene weight and embryo weight, but varied inversely with pericarp weight. Variable achene weight is evolutionarily advantageous. Heavy achenes are at an advantage in that their proportionately larger embryos and thinner pericarps facilitate germination, promoting competitive establishment of seedlings. Lighter achenes are also at an advantage through increased dispersibility, and their relatively thick pericarp provides a persistent seed bank. Evolutionary pressures presumably maintain the variability in achene weight of var. pilosus. These results are discussed in the context of the early midsuccessional ecology of var. pilosus.     

THE ANATOMY AND THREE-DIMENSIONAL MORPHOLOGY OF ANNULARIA HOSKINSII SP. N.

Foliage attached to calamitean shoots is described from coal ball petrifactions of Middle and Late Pennsylvanian age. Leaves correspond to the compression-impression genus Annularia and thus represent the first attached members of this genus to be recognized as petrifactions. Individual leaves contain a single unbranched vascular bundle flanked by wide lateral laminar areas which occupy more than half the leaf cross sectional area. Stomata are confined to broad bands within concave furrows which parallel the vascular bundle on the abaxial leaf surface. Epidermal cells within these furrows are in rows aligned obliquely to the leaf axis, and the rows angle outward at a slight angle towards the leaf margin. Convolutions of the leaf-bearing axes result from nodal diaphragms which are oblique to the shoot axis. Whorled leaves apparently radiate outward in the plane of each obliquely positioned nodal diaphragm. This petrified material helps explain the apparent flattening of entire nodal diaphragms and leaf whorls within the same plane as seen in compression specimens. Annularia hoskinsii sp. n. is proposed, and the systematic position of structurally preserved Annularia foliage relative to the genus Dicalamophyllum is discussed.     

New charophyte assemblage from middle Miocene lacustrine deposits of Moneva (Ebro Basin,Spain)

Two new fossil charophyte species from middle Miocene lacustrine deposits of Moneva (Ebro Basin, NE Spain) are described and illustrated. Sphaerochara miocenica nov. sp. is represented by medium sized gyrogonites with a characteristic spheroidal shape and ornamented with numerous small and regularly spaced tubercles arranged along the spiral cells. Several specimens show an unusual carbonate encrusted layer that covers completely or partially the gyrogonite. Psilochara monevaensis nov. sp. is characterized by large gyrogonites, with typical prolate shape and protruding apical poles. A second population of S. miocenica nov. sp. from a distant early upper Miocene lacustrine basin located in the Middle East (Bekaa Valley, Lebanon), identified in a previous study as Sphaerochara sp., is described and illustrated here, allowing the comparison of these distant populations. Ecologically, the associated fauna and facies from both localities suggest that these taxa grew in very shallow athalassic lakes. Interestingly, S. miocenica nov. sp. having a wide geographic distribution in peri-Mediterranean lakes with variable salinity, may become a fossil guide for the Miocene, providing at the same time important palaeoecological information.     

Latest Oligocene through early middle Miocene diatom biostratigraphy of the eastern tropical Pacific

Study of DSDP Sites 71, 77, and 495 has allowed the development of a refined diatom biostratigraphy for the latest Oligocene through early middle Miocene of the eastern tropical Pacific which is well correlated to the low-latitude zonations for planktonic foraminifers, coccoliths, and radiolarians. Six zones and 7 subzones are proposed, and correlation with high-latitude diatoms zonations for the North Pacific, the Norwegian Sea, and the Southern Ocean is suggested by the discovery of selected diatoms in these tropical sediments which were previously thought to be restricted to high latitudes. Six new species and one new variety of diatoms which are stratigraphically useful are proposed: Actinocyclus hajosiae, n. sp., A. radionovae, n. sp., Coscinodiscus blysmos, n. sp., C. praenodulifer, n. sp., Craspedodiscus rydei, n. sp., Thalassiosira bukryi, n. sp., and Coscinodiscus lewisianus var. robustus n. var.     

Morphology and Infraciliature of Trochiliopsis australis N. Sp., Pelagohalteria viridis (Fromentel, 1876) N. G., N. Comb., and Strobilidium lacustris N. Sp. (Protozoa,Ciliophora)1

Three ciliate species from Australia and Norway were examined by silver impregnation, biometry, and scanning electron microscopy. Trochiliopsis australis n. sp. (order Nassulida, family Microthoracidae) differs from the single other known species of the genus, T. opaca, by its prominent ridges on the left side, the distinctly longer anterior segment of somatic kinety 2, and by the doubled total number of kinetosomes. Pelagohalteria n. g. (order Oligotrichida, family Halteriidae) differs from Halteria by the structure of the bristle complexes, which are composed of a vertically and a horizontally oriented row of kinetosomes. Two Halteria species belong to the new genus: P. viridis (Fromentel, 1876) n. comb., which is redescribed here, and P. cirrifera (Kahl, 1935) n. comb. Strobilidium lacustris n. sp. (order Oligotrichida, family Strobilidiidae) differs from its nearest relative, S. velox, by the smooth pellicle, the absence of symbiotic green algae, and by its larger size.     

Comparative exine ontogeny in some members of the family Zygophyllaceae sensu lato

Summary. Exine ontogeny is studied in five taxa of the family Zygophyllaceae sensu lato (Peganum harmala L., Zygophyllum album L., Fagonia cretica L., Tribulus terrestris L., and Nitraria retusa [Forsk.] Asch.). In the beginning of the tetrad stage, the plasmalemma is attached to the callose wall, except in T. terrestris, where it describes crests and hollows. The primexine matrix is fibrillar, bilayered in T. terrestris and unilayered in the other taxa. In all species except P. harmala, the procolumellae are heterogeneous with clear zones and they become compact later. In T. terrestris, they are built on the crests. In Z. album and T. terrestris, a primordial nexinic lamella is set up. It is tripartite with a white line seen at some levels; on its external leaflet, the foot layer is observed, and on its internal leaflet, there is the endexine with numerous lamellae. This white line disappears often in the mature exine. In T. terrestris, there is a thick nexine that is coarsely lamellate inside. In the aperture zone, the columellae are lacking, the tectum and the foot layer get thinner; they unite and form the apertural membrane with the external part of the endexine. There is a granulolamellar endexinic zone well developed in P. harmala, whereas it is threelayered and weakly developed in T. terrestris. Correspondence and reprints: Laboratoire de Botanique Fondamentale et Appliquée, Faculté des Sciences, Université de Tunis El Manar, Campus universitaire, 1060 Tunis, Tunisia.     

Achene germination of the spring ephemeroid species Carex physodes in the Gurbantunggut Desert

Much of the seed germination research on Carex has focused on wetland species, and little is known about the species of arid habitats. Here, we investigated seed dormancy and germination of Carex physodes, which is an important component of the plant community of the Gurbantunggut Desert of the Junggar Basin in Xinjiang, China. Our studies included the effects of mechanical and chemical scarification, dry storage, treatment with GA₃, wet‐cold stratification, and burial in the field. No freshly matured achenes germinated over a range of temperature regimes after treatment with GA₃, 6 months of dry storage or removal of part of the endosperm. The mechanical scarification resulted in < 5% achene germination, however, higher percentage of achene germination occurred after removal of the pericarp (60%), H₂SO₄ scarification (30%) or scarification in 10% NaOH (85%). Six and nine months of wet‐cold stratification promoted < 40% achene germination. The optimal germination temperatures ranged from 25/10°C to 35/20°C. Maximum germination after 9 months of burial at a depth of 3 cm in the field was 36%. These results indicate that the seeds have non‐deep physiological dormancy (PD) and that the pericarp contains germination inhibitors and has strong mechanical resistance to germination.     

Megapedetes aegaeus N. SP. (Pedetidae) et a propos d'autres “rongeurs africains” dans le Miocene d'Anatolie

Three species of so-called “African rodents” (Megapedetes aegaeus n. sp., Phiomyidae indet. and Dakkamys sp.) have been recently discovered in Western Anatolia in the Middle Miocene localities of Bayraktepe, Chios and Yeni Eskihisar. The first species alone is described and discussed in this paper. The occurence of such rodents in Anatolia leeds to an evaluation of the special paleogeographic position of Africa to Asia at this time.     

A DESCRIPTION OF HAPLOZOON AXIOTHELLAE N. SP., AN ENDOSYMBIONT OF THE POLYCHAETE AXIOTHELLA RUBROCINCTA12

A new parasitic dinoflagellate, Haplozoon axiothellae sp. nov., is described from the intestine of the marine polychaete Axiothella rubrocincta. The parasites are 40–175 μm long with 2–26 cells arranged in single or double rows. Two cytoplasmic inclusions previously unknown in this genus are described. The first is globular and varies in size, while the second is approximately 2 μm long and peanut-shaped. The function and composition of the inclusions are unknown. Nuclear structure and karyokinesis are apparently different from those of typical dinoflagellates.     

Hippotraginae (Bovidae,Artiodactyla, Mammalia) from the Late Miocene of Tuva

Fossil remains of Late Miocene (Baode, NMU10-NMU11) horse antelopes from Tuva (Russia) are described, including Tragoreas sp., Protoryx tuvaensis sp. nov. from the Taralyk Cher locality and Quirliqnoria sp. from the Kholu locality. A new species, Protoryx tuvaensis Dmitrieva et Serdyuk, is described. These taxa compose a Late Miocene antelope assemblage of a new eastern geographical point (Russia, Tuva, Baode, NMU10-MN11).     

Fossil woods from Janggi Group (Early Miocene) in Pohang Basin,Korea

Sixty-four silicified fossil woods were collected from the Early Miocene Upper Coal-bearing Formation of Janggi Group in Pohang City, the Korean Peninsula. Out of them 23 specimens were identified as gymnosperms and 27 specimens as dicotyledons. The taxa identified include Picea palaeomaximowiczii Watari, Taxodioxylon cunninghamioides (Watari) Watari, T. sequoianum (Merckl.) Gothan, Fagus hondoensis (Watari) Watari, Cercidiphyllum sp., Camellia japonoxyla Suzuki et Terada, Distylium chiharu-hirayae Suzuki et Terada, Aesculus sp., Wataria miocenica (Watari) Terada et Suzuki and W. parvipora Terada et Suzuki. All of these species are reported for the first time from the Tertiary basins of Korea. Compared with those of the Miocene Formations in Japan, most taxa we found are common between the paleo-floras in Korea and Japan during the Early to Middle Miocene.