Two new rheophytic species of Schistidium (Grimmiaceae) from China

Abstract

Two new species of Schistidium Bruch & Schimp., S. riparium H.H.Blom, Shevock, D.G.Long & Ochyra, and S. mucronatum H.H.Blom, Shevock, D.G.Long & Ochyra, are described and illustrated. They occur in rheophytic habitats in China, S. riparium in the southern Hengduan Mountains in Yunnan Province (Lancang Jiang and Nu Jiang catchments) and S. mucronatum from further north, on the Qinghai–Tibet Plateau of Sichuan and Qinghai Provinces (Jinsha Jiang and Huang He catchments). The affinities of the new species are discussed and on the basis of their concave and broadly canaliculate leaves with plane and erect margins, S. riparium is tentatively placed in Schistidium Bruch & Schimp. subgen. Canalicularia Ochyra, whereas S. mucronatum on account of its keeled, ovate-lanceolate leaves and the strongly curved and twisted peristome teeth resembles very much species of sect. Apocarpiformia (Kindb.) Ochyra within subgen. Apocarpa Vilh.     

Bucklandiella allanfifei (Grimmiaceae), a new moss species from New Zealand,with a note on South American B. striatipila

Abstract

A new species, Bucklandiella allanfifei Bednarek-Ochyra, is described from New Zealand. The new species belongs to Bucklandiella Roiv. sect. Marginatae (Bednarek-Ochyra) Bednarek-Ochyra & Ochyra and is allied to southern South American B. striatipila (Cardot) Bednarek-Ochyra & Ochyra. Bucklandiella allanfifei is characterized by the smaller stature of the plants, mostly prostrate and profusely branched stems, most often with short, erect-ascending branchlets, shorter leaves, 1.5–2.1 mm long (without a hair-point) and anatomy of the costa which is reniform to crescent-shaped in cross-section and 3(–4)-layered in the proximal part. Additionally, the laminal cells are short-rectangular in the distal and median parts, (15–)20–30(–40) μm long, the basal marginal border is composed of 3–4 rows of hyaline, translucent, esinuose and rectangular cells, the innermost perichaetial leaves are longly pilose, the capsules are ellipsoid to short-cylindrical, 1.5–2.0 mm long and the setae are short, (2.2–)3.0–4.5(–6.0) mm. Bucklandiella striatipila is briefly assessed taxonomically and it is considered to be definitely distinct from B. crispipila (Taylor) Bednarek-Ochyra & Ochyra, a pan-tropical oreophyte, with which it was prematurely considered conspecific. Racomitrium integripilum Dusén, R. gemminatum Roiv. and R. substriatipilum Roiv. are reduced to synonymy with B. striatipila. Two new combinations are made: Buckladiella elegans (Müll. Hal.) Bednarek-Ochyra & Ochyra and B. pycnotricha (Müll. Hal.) Bednarek-Ochyra, Ochyra & Seppelt.     

Fissidens traversii,a new species from Queensland,Australia

Abstract

Fissidens traversii, a new species from Queenslahd, Australia, is characterised by the rounded leaf apex, costa papillose and finishing short of the apex, mamillose, multipapillose cells, short dorsal lamina and vaginant laminae (which usually have a marginal strip of transversely elongated calls in the lower half), reaching almost to the apex of the leaf.     

Two-hundred-years old shoots of the epiphytic moss Brotherella henonii preserved in a bark pocket of the conifer Cryptomeria japonica

Abstract

Schistidium flaccidum (De Not.) Ochyra is recorded as new to Britain from Snowdon, Wales. It may be distinguished from the other British species of the genus by its poculiform capsule, absence of peristome and small, dense tufts. Notes are given on its separation from Grimmia anodon, which it resembles more closely.     

Thamnobryum cataractarum,a new species from Yorkshire,with observations on T. angustifolium and T. fernandesii

Abstract

Thamnobryum cataractarum sp. nov. is described from Yorkshire, England. It is most closely related to T. fernandesii from Madeira and is also similar to T. angustifolium from Derbyshire, England. The three species are compared, and the habitat of the new species is described. T. fernandesii and T. cataractarum are retained in Thamnobryum rather than in Crassiphyllum Ochyra.     

Hymenostylium xerophilum,sp. nov., and H. gracillimum,comb. nov., two neglected European mosses and their molecular affinities

Abstract

Hymenostylium xerophilum is described as a new species from the European Alps. Molecular rps4 and ITS data support its recognition and elucidate its affinities to other species of the tribe Pleuroweisieae. It is closely related to H. gracillimum, comb. nov., which is based on the old and neglected Gymnostomum gracillimum, which replaces the recent name G. boreale. Both species share non-coloured to pale yellowish-brown rhizoids, stem central strand and indistinct sclerodermis, keeled leaves, and concave laminae in abaxial view. They differ from each other in leaf shape and several essentially quantitative characters. Sporophytes have never been found in H. xerophilum, but they are known from several localities in H. gracillimum. The former colonizes rather dry, sunny to half-shaded calcareous rocks, whereas the latter needs moist and shaded rock habitats and shows a preference for subneutral slate. At present, H. xerophilum is known only from the Alps (Austria, and a single site in Germany), where it is rather widespread in calcareous regions. H. gracillimum seems to be a distinctly rarer plant, to date known only from eight Austrian sites and one locality in Russian Karelia. Other published records under the name G. boreale have been wrongly attributed to this species. Lectotypes are designated for G. gracillimum and Gyroweisia acutifolia. A key to Hymenostylium and the genera of Pleuroweisieae in Europe is presented.

Thicker rhizoids of both species are covered with a thick, non-coloured protective layer and filled with oil-droplets and leucoplasts. They represent a subterranean secondary protonema, which plays an important role in the survival and propagation of these mosses, vital especially in the case of the non-sporulating H. xerophilum.     

Genetic analyses of the formation of the serrated margin of leaf blades in Arabidopsis : combination of a mutational analysis of leaf morphogenesis with the characterization of a specific marker gene expressed in hydathodes and stipules

Developmental control of the formation of the serrated margin of leaf blades was investigated. First, the expression was characterized of a marker gene encoding β-glucuronidase in strain #1-35-38, a transgenic strain of Arabidopsis thaliana (L.) Heynh, derived by the use of a previously described transposon-tagging system. In strain #1-35-38, expression of the marker gene was tissue-specific, being restricted to stipules and the toothed margins of laminae. Using this transgenic marker gene, we examined the development of leaf blade margins in Arabidopsis. We compared the pattern of expression of the marker gene in the leaves of the wild-type plant with that in plants carrying the asymmetric leaves1 (as1) mutation, which causes dramatic changes in leaf-blade morphology in Arabidopsis. The as1 mutant showed normal morphology of early leaf primordia. The mutation affected the development of leaf segmentation in Arabidopsis without any change in the number or morphology of cells in laminae. The as1 mutation affected leaf morphology independently of mutations in other genes known to affect leaf morphogenesis, such as the acaulis1 mutation and the angustifolia mutation. Based upon these results, the development of the morphology of leaf margins in Arabidopsis is discussed. Received: 9 January 1997 / Accepted: 24 June 1997     

Cytokinins in Xanthium strumarium: A Rapid Response to Short Day Treatment

Following a single inductive short day, cytokinin activity in extracts of leaf laminae, buds and root exudate of Xanthium strumarium L. (as measured by the soybean callus bioassay) declined to between 10 and 25% of the level detected under long-day conditions. Additional inductive cycles, up to five, produced little further change. Cytokinin activity of petiole extracts fluctuated and did not decline to the same extent as that of leaf laminae, buds or exudate.     

A revision of the moss genus Sciaromium (Mitt.) Mitt. I. General remarks and the section Aloma Dusén

Abstract

The generic name Sciaromium (Mitt.) Mitt. that was originally used as a sectional epithet in Leskea is synonymous with Echinodium Jul E. madeirense Jur. [= E. spinosum (Mitt.) Jur.] is selected as the lectotype of the genus Echinodium. A historical review of taxonomic and nomenclatural problems in Sciaromium is provided and taxa that had previously been excluded from this genus are briefly discussed. Sciaromium flavidulum Dusén is a Eurhynchium and the combination E. flavidulum (Dusén) Ochyra is made. Sciaromium sect. Aloma Dusén is synonymous with Eurhynchium since E. flavidulum serves as the type species of this section. The taxonomic position of S. gracile Dusén is discussed and this species is considered synonymous with Amblystegium chilense Lor., which is transferred to Pseudoleskea and the appropriate new combination P. chilensis (Lor.) Ochyra made. Type specimens of S. bellii Broth., S. elimbatum Broth. & Watts and S. forsythii Broth. in Broth. & Watts are briefly described and illustrated; these species are reduced to synonymy with the polymorphic Cratoneuropsis relaxa (Hook. f. & Wils.) Fleisch. in Broth.     

Wheat tissues freeze-etched during exposure to extracellular freezing: distribution of ice

Pieces excised from leaf bases and laminae of seedlings of Triticum aestivum L. cv. Lennox were slowly frozen, using a specially designed apparatus, to temperatures between 2° and 14° C. These treatments ranged from non-damaging to damaging, based on ion-leakage tests to be found in the accompanying report (Pearce and Willison 1985, Planta 163, 304–316). The frozen tissue pieces were then freeze-fixed by rapidly cooling them, via melting Freon, to liquid-nitrogen temperature. The tissue was subsequently prepared for electron microscopy by freeze-etching. Ice crystals formed during slow freezing would tend to be much larger than those formed during subsequent freeze-fixation. Ice crystals surrounding the excised tissues were much larger in the frozen than in the control tissues (the latter rapidly freeze-fixed from room temperature). Large ice crystals were present between cells of frozen laminae and absent from controls. Intercellular spaces were infrequent in control leaf bases and no ice-filled intercellular spaces were found in frozen leaf bases. Intracellular ice crystals were smaller in frozen tissues than in controls. It is concluded that all ice formation before freeze-fixation was extracellular. This extracellular ice was either only extra-tissue (leaf bases), or extra-tissue and intercellular (laminae). Periplasmic ice was sometimes present, in control as well as slowly frozen tissues, and the crystals were always small; thus they were probably formed during freeze-fixation rather than during slow freezing. The plasma membrane sometimes showed imprints of cell-wall microfibrils. These were less abundant in leaf bases at 8° C than in controls, and were present on only a minority of plasma membranes from laminae. Therefore, extracellular ice probably did not compress the cells substantially, and changes in cell size and shape were possibly primarily a result of freezing-induced dehydration. Fine-scale distortions (wrinkles) in the plasma membrane, while absent from controls, were present, although only rarely, in both damaged and non-damaged tissues; they were therefore ice-induced but not directly related to the process of damage.     

A new species of Acanthosyris (Santalaceae) from Bolivia and a key to the woody South American Santalaceae

Acanthosyris asipapote, a new species from the vicinity of Santa Cruz, Bolivia, is described and illustrated. It is most similar to A. paulo-alvinii Barroso, known only from the state of Bahia, Brazil, but differs by leaf characters, pilose filaments, and smaller seeds. A key to the five woody genera and nine species of Santalaceae in South America is provided. Cervantesia, Jodina, and Myoschilos are probably monotypic; Santalum (in South America) has a single species, and Acanthosyris has five species.     

稀土元素富集对白云鄂博矿区8种常见藓类植物生长及其解剖结构特征的影响

以白云鄂博稀土矿区不同生境下常见的8种藓类(缨齿藓、尖叶对齿藓、真藓、短叶对齿藓、中华赤藓、黑对齿藓、闭蒴盐土藓、卷叶墙藓)为实验材料,以内蒙古贺兰山、桑根达来的同种植物标本为对照材料,利用体式显微镜和光学显微镜,对苔藓植物体的分枝状况和茎叶的解剖结构特征进行观察比较,探讨稀土元素对苔藓植物生长的影响。结果表明:(1)两地8种藓类植物在株高、茎宽、叶长和叶宽4个指标方面几乎都存在显著差异,而叶的长宽比和叶细胞(上部、中部、基部)长宽比差异不显著。(2)白云鄂博3个不同矿区的3种藓类植物在叶长和叶宽方面都是西矿主矿东矿,且西矿与东矿间差异显著;3个不同矿区植物的茎宽没有规律。(3)稀土元素含量是影响不同矿区苔藓植物生长的主要因素,并可能通过叶片影响植物体的生长。     

The status of Platyhypnidium mutatum Ochyra & Vanderpoorten and the systematic value of the Donrichardsiaceae based on molecular data

Abstract

Base sequences of 376 bp of chloroplast DNA and of 521 bp of nuclear ribosomal DNA of the newly described Platyhypnidium mutatum Ochyra & Vanderpoorten and Platyhypnidium riparioides (Hedw.) Dixon are identical with the exception of one substitution in the nuclear ribosomal DNA. From these almost identical base sequences and the identical sporophytes found in both species, it is concluded that Platyhypnidium mutatum is a somatic mutant of the latter species differing by a bistratose lamina and a broader nerve. Previous to these results, Platyhypnidium mutatum would have been placed in the genus Donchrichardsia because of its vegetative morphological characters. It is therefore concluded that the family Donrichardsiaceae is artificial in spite of its strong morphological integrity.     

Four new hepatics from Australia

Abstract

A new species, Racomitrium patagonicum Bednarek-Ochyra &; Ochyra, is described from southern South America. A herbarium name, R. senile Schimp. in A. Jaeger, is considered synonymous with R. patagonicum and confusion associated with its interpretation is explained. The new species belongs to the type subgenus of Racomitrium and is closely alied to R. lanuginosum (Hedw.) Brid. from which it differs by the very long and broadly decurrent, ruffled or wavy margins of the hyaline hair-point, broadly canaliculate leaves and dull green, strongly papillose laminal cells. Grimmia glacialis Müll. Hal., hom. illeg. (=Racomitrium glaciale Kindb.) from South Georgia is typified and this name is considered synonymous with Racomitrium lanuginosum subsp. lanuginosum. Distribution of the new species is mapped. A key to species of Racomitrium subg. Racomitrium is provided.     

Obituaries

Abstract

The history and nomenclatural problems of the name Limbella are reviewed, the correct citation of the generic name being Limbella (C. Muell.) Broth. The genus consists of two species, L. tricostata (Sull.) Broth. and L. fryei (R. S. Williams) Ochyra which are described. L. tricostata is endemic to the Hawaiian Islands and L. fryei to Oregon on the Pacific coast of North America. Sporophytes are recorded for the first time in L. tricostata. The family relationships of Limbella are discussed and it is placed in the Thamnobryaceae, close to Thamnobryum.     

Riccia rhenana Lorb. ex. K.Mill. in Britain

Abstract

A single, small moss leaf has been found among very small amounts of contents extracted from the Tyrolean Iceman's colon. It belongs to the species Neckera complanata Hedw., a woodland moss of low to moderate altitudes. The leaf was accidently ingested and not consumed as food.     

Relationships among Cratoneuron curvicaule,C. filicinum var. filicinum,and C. filicinum var. atrovirens (Bryophyta: Amblystegiaceae)

Abstract

The relationships among western Eurasian and Macaronesian Cratoneuron filicinum (Hedw.) Spruce var. filicinum, C. filicinum var. atrovirens (Brid.) Ochyra, and C. curvicaule (Jur.) G.Roth were explored by ITS and the chloroplast markers rpl16 and tRNA-Gly. Haplotype networks, Jacknife, and Neighbour joining trees all provide high support for the recognition of C. curvicaule as distinct from C. filicinum, whereas the two varieties of the latter could not be distinguished. It is concluded that C. filicinum var. atrovirens most likely represents a phenotypic modification of C. filicinum that occurs especially in certain submerged environments or under heavily dripping water. The maximal support for the Cratoneuron clade and the small and quantitative morphological differences between its two species are arguments for not splitting this genus.     

Review of the neotropical endemics Burmeistera, Centropogon, and Siphocampylus (Campanulaceae: Lobelioideae), with description of 18 new species and a new section

Burmeistera, Centropogon, and Siphocampylus together comprise more than 500 species endemic to the Neotropics, Current knowledge of these genera is unsatisfactory, with much diversity yet to be described. Over the past seven years, one out of every 28 specimens received for identification has represented a new species, many characterized by unique or unusual character states. Siphocampylus smilax (Bolivia) is unique in the genus in its parallelodromous leaf venation and extra-floral nectaries. Centropogon dianae (Peru) cannot be accommodated in any recognized infrageneric taxon, and a new section, Centropogon sect. Niveopsis, is proposed for it. The flowers of C. steinii (Ecuador) are the smallest known in the genus, while C. connatilobatus (Venezuela) is the first species to combine arbusculiform pubescence and connate calyx lobes. Burmeistera venezuelensis is only the second species of the genus known to occur in Venezuela and the first to be endemic; similarly, Centropogon wilburii is only the third species of Centropogon known from Mexico and the first to be endemic to that country. Additional novelties are also described.