A new species of Jonesiobryum (Bryopsida: Rhachitheciaceae) from Uganda

Abstract

Jonesiobryum dumboi is described as a new moss species from Uganda. It differs from its congeners by possessing more broadly obovate leaves and a costa that ends well below the apex. The species is only known from the type locality where it was collected on branches in the canopy.     

The genus Racomitrium (Grimmiaceae) in Brazil, with the first report of R. subsecundum in South America

Four species of the moss genusRacomitrium Brid. are reported from Brazil:R. subsecundum (Harv.) Wils,R. didymum (Mont.) Lorentz,R. crispipilum (Taylor) A. Jaeger, andR. visnadiae W. R. Buck.Racomitrium subsecundum is reported for the first time from South America in Brazil and Colombia. The species is fully described and illustrated.Racomitrium didymum is recorded for the first time from Brazil; the specimens previously assigned toR. crispulum (Hook.f. & Wils.) Hook.f. & Wils. represent this species.Racomitrium cucullatifolium Hampe andR. crispulum (Hook. f. & Wils.) Hook.f. & Wils. are excluded from the Brazilian bryophyte flora. All Brazilian species ofRacomitrium are briefly assessed taxonomically and bryogeographically and illustrated, and a key to their determination is given. A lectotype is selected forGrimmia didyma Mont.     

中国球藓属(丛藓科)植物分布新资料

报道了球藓密疣变种在中国的新分布。该变种主要分布于欧洲、大洋洲和北美洲,在中国为首次记录。该文对其形态特征进行了详细的描述与拍照,凭证标本存放于内蒙古大学植物标本馆(HIMC)。     

卷叶薄齿藓和北美赤藓形态特征及其地理新分布

通过对采自贵州省梵净山和内蒙古赛罕乌拉自然保护区的苔藓植物标本进行鉴定,发现了丛藓科的2个新分布种——卷叶薄齿藓(Leptodontium pungens)和北美赤藓(Syntrichia amphidiacea)。卷叶薄齿藓为中国新记录种,首次在中国贵州省梵净山发现,其主要特征为茎无中轴分化,具透明层,常分布于火山和温带高海拔地区。北美赤藓为内蒙古新分布种,发现于内蒙古赛罕乌拉自然保护区,其主要特征为叶腹面近叶尖处生有大量芽胞,成熟芽胞棕色,多细胞,圆柱状。本研究对卷叶薄齿藓和北美赤藓的形态特征和地理分布进行了具体描述,并提供了图版和分种检索表。     

中国新记录种——摩拉维采真藓(新拟)

该文首次报道了摩拉维采真藓(新拟)在中国的分布。研究表明:(1)摩拉维采真藓的主要识别特征为:叶常聚集在茎顶成莲座状,叶倒卵状披针形至匙形,具长毛尖,具分化边缘,中肋消失于叶尖下,叶细胞长菱形至六边形,叶腋处着生大量单列细胞构成的分枝或不分枝的丝状芽胞。(2)通过对摩拉维采真藓的命名和系统位置的讨论,确认该种是真藓属细叶真藓组的有效种。(3)摩拉维采真藓与近缘种细叶真藓和幽美真藓有诸多相似特征:莲座状的茎顶、有分化边和菱形至六边形中上部细胞的倒卵形叶,但该种以具有大量叶腋生丝状芽胞和叶中肋不及顶等特征区别于细叶真藓的无腋生芽胞、叶中肋突出叶尖成长芒状,以具有叶湿时平展、干时卷曲和叶腋有芽胞等特征区别于幽美真藓的叶湿时内凹、干时紧贴于茎和无腋生芽胞;拟三列真藓、圆叶真藓和灰黄真藓的部分种群都曾报道有与摩拉维采真藓相似的腋生丝状芽胞,但摩拉维采真藓的假根集生于植株基部、叶有狭分化边、叶缘平直、中肋消失于叶尖下而区别于拟三列真藓的茎中下部密被假根、叶有宽分化边、叶缘背卷、中肋及顶或短出,摩拉维采真藓有分化边和长毛尖的倒卵状披针形区别于圆叶真藓叶有无分化边和圆钝叶尖的卵圆形叶,区别于灰黄真藓有中肋及顶和短尖的卵状披针形叶;柔叶真藓有与摩拉维采真藓相似、中肋不及顶的叶,但无芽胞而易与新记录种区分。(4)该种在北温带有较广泛分布,形成欧洲-北亚-中亚-西亚和北美两个主要分布区;作者在四川和新疆等地的发现可以推测摩拉维采真藓在中国可能有更广泛的分布。     

The propagule supply, litter layers and canopy shade in the littoral community influence the establishment and growth of Myriophyllum aquaticum

The exotic macrophyte species Myriophyllum aquaticum (Vell.) Verdc. is widely dispersed, mainly through stem fragments and rhizomes, in shallow littoral zones in which uniform canopy conditions are created by the pre-existing resident wetland plant species. Therefore, interactions between these two types of asexual propagules and the resident species may occur during the early establishment and growth phases of M. aquaticum. We tested the hypothesis that the establishment and growth of M. aquaticum are affected by three factors: the number of propagules supplied, the presence of a standing biomass of Carex japonica Thunb. and the presence of thick litter layers in the littoral zone. M. aquaticum rhizomes and stem fragments were introduced into a standing biomass of C. japonica in mesocosms using two types of sediments (littoral and sand-clay) and two propagule supply levels. After 4?months, the survival rates of both the rhizomes and stem fragments were high under all of the experimental treatments. The propagule supply positively affected the survival rates and growth of M. aquaticum. The survival of the rhizomes was unaffected by the presence of either C. japonica or littoral sediments, whereas the survival of the stem fragments was reduced by the presence of C. japonica. The presence of litter layers is a primary factor facilitating the growth of M. aquaticum propagules because of the high nutrient content of the litter. In addition, the presence of the standing C. japonica biomass and newly growing Eleocharis yokoscensis (Franch.et Sav.) Tang et Wang (a small ruderal species that, unexpectedly, grew rapidly following the removal of the standing biomass of C. japonica) reduced the growth of the M. aquaticum stem fragments and rhizomes, respectively. Our findings suggest that the loss of vegetative cover resulting from intense cattle herbivory and other factors in littoral zones may accelerate the invasion of M. aquaticum. An effective approach for preventing M. aquaticum invasion is to reduce the propagule supply and prevent propagules from dispersing.     

Taxonomy and distribution of Clematis,sect. Atragene (Ranunculaceae), in North America

Two North American species ofClematis, sect.Atragene (L.) DC, are recognized.C. occidentalis (Hörnern.) DC. is divided into three varieties, native respectively to eastern North America, the Rocky Mountains, and the Cascade Mountains of Washington.C. columbiana (Nutt.) Torr. & Gray is divided into two extensively intergrading varieties, one prevailing in the southern Rocky Mountains, the other in the northern foothills and in outlying mountain ranges. After a study of the type specimen ofC. columbiana, it was concluded that this name should be applied to the species hitherto commonly known asC. pseudoalpina (O. Kuntze) A. Nels., rather than to the taxon with which it has usually been associated. The two species are evidently closely related and appear occasionally to have hybridized in nature.     

Impact of the invasive moss Campylopus introflexus on carabid beetles (Coleoptera: Carabidae) and spiders (Araneae) in acidic coastal dunes at the southern Baltic Sea

Campylopus introflexus is an invasive moss in Europe and North America that is adapted to acidic and nutrient-poor sandy soils with sparse vegetation. In habitats like acidic coastal dunes (grey dunes) it can reach high densities, build dense carpets and modify habitat conditions. While the impact of the moss invasion on the vegetation is well analyzed, there is a lack of knowledge regarding possible effects on arthropods. In the present study we analyzed the impact of Campylopus introflexus on the ground-dwelling arthropods carabid beetles and spiders, as both taxa are known to be useful indicator taxa even on a small-scale level. In 2009 we compared species composition in a) invaded, moss-rich (C. introflexus) and b) native, lichen-rich (Cladonia spp.) acidic coastal dunes by using pitfall traps. A total of 1,846 carabid beetles (39 species) and 2,682 spiders (66 species) were caught. Species richness of both taxa and activity densities of spiders were lower in invaded sites. Species assemblages of carabids and spiders differed clearly between the two habitat types and single species were displaced by the moss encroachment. Phytophagous carabid beetles, web-building spiders and wolf spiders were more abundant in native, lichen-rich sites. Shifts in species composition can be explained by differences in the vegetation structure, microclimate conditions and most likely a reduced food supply in invaded sites. By forming dense carpets and covering large areas, the moss invasion strongly alters typical arthropod assemblages of endangered and protected (EU-directive) acidic coastal dunes.     

Didymodon liae sp. nov. (Pottiaceae) from Tibet,China

Didymodon liae J. Kou, X.‐M. Shao & C. Feng sp. nov., is described and illustrated from Dagzê County in south central Tibet, China. The new species is most similar to Didymodon australasiae (Hook. & Grev.) R. H. Zander, but differs in plants growing loosely in a thin turf, stems without hyalodermis and sclerodermis, margins recurved from just above the base nearly to the apex, laminal cells strongly bulging, mammillose, covered with simple or forked papillae, and costa with a layer of ventral substereids. The new species is contrasted with other similar species of the genus. Information on its distribution and ecology is also provided.     

A Ceratopsian Dinosaur from the Lower Cretaceous of Western North America,and the Biogeography of Neoceratopsia

The fossil record for neoceratopsian (horned) dinosaurs in the Lower Cretaceous of North America primarily comprises isolated teeth and postcrania of limited taxonomic resolution, hampering previous efforts to reconstruct the early evolution of this group in North America. An associated cranium and lower jaw from the Cloverly Formation (?middle–late Albian, between 104 and 109 million years old) of southern Montana is designated as the holotype for Aquilops americanus gen. et sp. nov. Aquilops americanus is distinguished by several autapomorphies, including a strongly hooked rostral bone with a midline boss and an elongate and sharply pointed antorbital fossa. The skull in the only known specimen is comparatively small, measuring 84 mm between the tips of the rostral and jugal. The taxon is interpreted as a basal neoceratopsian closely related to Early Cretaceous Asian taxa, such as Liaoceratops and Auroraceratops. Biogeographically, A. americanus probably originated via a dispersal from Asia into North America; the exact route of this dispersal is ambiguous, although a Beringian rather than European route seems more likely in light of the absence of ceratopsians in the Early Cretaceous of Europe. Other amniote clades show similar biogeographic patterns, supporting an intercontinental migratory event between Asia and North America during the late Early Cretaceous. The temporal and geographic distribution of Upper Cretaceous neoceratopsians (leptoceratopsids and ceratopsoids) suggests at least intermittent connections between North America and Asia through the early Late Cretaceous, likely followed by an interval of isolation and finally reconnection during the latest Cretaceous.     

Redescription of the geologically youngest albanerpetontid (?Lissamphibia): Albanerpeton inexpectatum Estes and Hoffstetter, 1976, from the Miocene of France

Albanerpeton inexpectatum Estes and Hoffstetter, 1976, the type species of Albanerpeton and the geologically youngest albanerpetontid, is rediagnosed and redescribed based on a large collection of jaws and frontals from Miocene fissure fills near La Grive-Saint-Alban, southeastern France. Intraspecific variation is documented in these elements, and is attributed to growth and individual differences. Synapomorphies of the upper jaws indicate that A. inexpectatum a) belongs in a clade whose members are otherwise known from the Upper Cretaceous-Paleocene of North America and b) is the sister species of an undescribed North American Paleocene species. The presence of A. inexpectatum in the Miocene of France is postulated to be the result of an Early or Middle Tertiary dispersal of an unknown ancestral species from North America into Europe. Cranial apomorphies of A. inexpectatum are interpreted as having strengthened the skull for burrowing in rocky soil and feeding.     

Collicrinus excavatus (Hall, 1861), generic affinity for a Lower Mississippian crinoid (Phylum Echinodermata)

Platycrinites was long a “catch-all” genus that was loosely defined in North America. Ausich and Kammer (2009) rectified the inconsistencies of generic diagnoses to define the Platycrinitidae better; however, due to preservation, many species were not known from specimens with sufficient characters to be placed confidently into a genus and, thus, were designated Platycrinites sensu lato. Collicrinus excavates (n. comb.) was one such species. A specimen with a complete theca and partial arms preserved was discovered in southwestern Missouri in the Burlington–Keokuk Limestone. With the discovery of this specimen, C. excavatus has been fully described and placed in the correct genus. Further, the associated fauna of new C. excavatus specimens, reported here, helps to evaluate the stratigraphic position of this species, which is now considered to be only from Burlington Pelmatozoan Association I and II, roughly equivalent to the Dolbee Creek and Haight Creek Members of the Burlington Limestone.     

Ecology of Racomitrium lanuginosum in British blanket mire - evidence from the palaeoecological record

Abstract

The moss Racomitrium lanuginosum (Hedw.) Brid. is widely distributed in the cool-oceanic north and west of the British Isles, where it is an important element in the vegetation of blanket mire. It has been described as occurring on the present-day surface of British blanket mire in two situations (i.e. where the local mire water table may be lowered, despite high atmospheric humidity), on the tops of tall hummocks and adjacent to areas of peat erosion, where it may be dominant in the vegetation. Accordingly, the occurrence of R. lanuginosum is widely perceived as indicative of drier mire conditions and/or mire degradation. In contrast, recent palaeoecological studies have documented the recurrence of R. lanuginosum in the absence of either hummock upgrowth or peat erosion. Such studies suggest that R. lanuginosum may also occur on blanket mire as a component of climatically-mediated mire development. This paper presents critical new data to document the decomposition of R. lanuginosum and describes the results of recent palaeoecological studies that have negated the exclusive role of R. lanuginosum in mire drying/degradation. We present evidence for the active role of R. lanuginosum in persistent blanket mire development, suggesting the moss may occur during periods of climate change towards increased wetness, after a sustained period of drier conditions. The results are of wider relevance in evidencing the sensitivity of oceanic blanket mire to past climate change.     

Didymodon mesopapillosus sp. nov. (Pottiaceae) from Tibet,China

Didymodon mesopapillosus J. Kou, X.‐M. Shao & C. Feng is described and illustrated as a new species from Tibet, China. It is characterized mainly by its ovate to ovate‐lanceolate leaves appressed to weakly erect when dry, margins recurved from leaf base to apex, laminal cell superficial walls markedly thicker than the internal walls, laminal papillae present only on both sides of costa, short‐excurrent costa, undifferentiated basal cells and differentiated perichaetial leaves. This species is compared with similar species and its ecology is discussed.     

Didymodon caboverdeanus J.A.Jiménez & M.J.Cano (Pottiaceae,Musci), a new species from the Cape Verde archipelago

A new moss species, Didymodon caboverdeanus J.A.Jiménez & M.J.Cano, from the Cape Verde archipelago is described and illustrated. It differs most saliently from other species of Didymodon Hedw. by the combination of the lanceolate leaves with obtuse and often cucullate leaf apices, recurved margins, the yellowish colour in KOH, costa ending below the apex, laminal cells with low papillae over the transverse walls, which reach the two adjacent cells, the presence of gemmae in the leaf axils, and a short and straight peristome.     

A new species of the plesiosaur genus <Emphasis Type="Italic">Polycotylus</Emphasis> from the Upper Cretaceous of the southern Urals

The most complete specimen of the plesiosaur genus Polycotylus from the Upper Cretaceous of the southern Urals is described. This specimen has much in common with the species P. latipinnis described from North America, but differs in the limb structure and cranial bones, so that it is assigned to a separate species, Polycotylus sopozkoi sp. nov.     

The identity of Racomitrium obtusifolium (Musci,Grimmiaceae) from North America

Trichostomum obtusifolium P. Beauv. is lectotypified and the type material is briefly described and illustrated. It is shown that the species correctly belongs within the genus Anomodon Hook. & Tayl., not Racomitrium Brid., and it is synonymous with A. minor (Hedw.) Lindb. A brief nomenclatural note on A. minor is presented and its homotypic synonyms are listed.     

Neckera enrothiana (Neckeraceae,Musci), a new species from Sichuan,China

Abstract

A new species in the moss family Neckeraceae, Neckera enrothiana M.C. Ji is described and illustrated from the Sichuan Province, China. It is characterized by the combination of relatively small plants, entirely non-undulate and non-decurrent leaves, and by its lacking or very short costa. It is compared with the somewhat similar and widely distributed N. complanata (Hedw.) Hueb. and N. besseri (Lob.) Jur., as well as with the Asian N. goughiana Mitt.