中国丽藻属两新种

本文报道的是采自广西、山东的丽藻属植物两新种,即广西丽藻(Nitella guangxiensis)和山东丽藻(Nitella shandongensis),其特征分别描述如下: 广西丽藻新种图1:1—9 Nitella guangxiensis Y. J. Ling, G. Z. Deng et Z. Li, sp. nov. Planta monoica, claro-viridis, 13-19 cm alta. Caulis robustus,diametro 610-     

Some New Taxa of Nitella from Guangdong,China

Guangdong Province extends across the subtropical and tropical zones. With favorable climate and plentiful rainfall, this district is extremely rich in plants. However, the study on the Charophyta in this province is scanty. The specimens we identified were collected from 4 cities and 10 counties of the province. The result shows that there are abundant representatives of Chrophyta, especially in Nitella, in the province. In this paper, however, only reported are some new taxa of Nitella. The 2 new species are Nitella sessilis and N. guangdongensis; the 3 new varieties are Nitella flagelliformis var. conglomerata, N. brevidactyla var. hainanensis and N. pakistanica var. magniantheridii; and the 3 new records of distribution in China are Nitella bengalensis Kundu, N. madagascariensis Zanev. and N. tenuissima var. sanukensis Imah.     

New finds of charophytes in Iceland with an update on the distribution of the charophyte flora

Charophyte species new to the flora of Iceland are reported and an update on the distribution of the previously known species is given. Four species are new to Iceland; Chara aspera Willdenow, Chara contraria Braun ex Kützing, Tolypella canadensis Sawa and Tolypella glomerata (Desvaux) Leonhardi, while four species were previously known: Chara globularis Thuiller, Chara virgata Kützing, Nitella flexilis (L.) Agardh and Nitella opaca (Agardh ex Bruzelius) Agardh. The finding of the species new to Iceland add to the hitherto known worldwide distribution of those species, including a significant extension to the north.     

Some New Taxa of Charophyta in China

The authors examined specimens collected from Beijing, Hebei Province and North-east China. Two new species, one variety and five new records of the Characeae from China are reported in this paper. They are Nitella nenjiangensis sp. nov., Chara vertillibracteata sp. nov., C. globularis Thuiller var. beijingensis var. nov., Nitella axillaris Braun, N. crispa Imah., N. gracillima Allan, N. pseudoflabellata var. imperialis T. F. A., Chara arru-densis Mendes.     

Materials for the Charaphyta of China

Reported in this paper are two new species, one new variety, and three new records of the Characeae collected in China. They are Nitella anhuensis sp. nov., Chara paucicarpa sp. nov., Nitella alleninda var. tenuireticulata var. nov., N. gracilliformis J. Grove., N. formosa T. F. Allen and Chara tenuispina A. Br.     

Review: Taxonomy of Nitella (Charales, Charophyceae) based on comparative morphology of oospores and multiple DNA marker phylogeny using cultured material

The genus Nitella is the largest group in the Charales and has the highest diversity of vegetative and oospore morphologies. In his worldwide monograph on the Charales, R. D. Wood characterized the sections and species of Nitella mainly on the basis of vegetative morphology and treated oospore wall morphology as diagnostic at the infraspecific level. Therefore, many species of Nitella exhibiting distinct external morphology of the oospore wall (EMOW) were reduced to infraspecific rank and only 53 of 204 species previously described were recognized within Nitella . However, recent morphological and molecular phylogenetic studies have demonstrated the phylogenetic validity of using EMOW for diagnosing some species of Nitella . More recently, a scanning electron microscopy (SEM) study of internal morphology of the oospore wall (IMOW) and multiple DNA marker analyses using both nuclear and chloroplast gene sequences were conducted to improve our understanding of the taxonomy of Nitella at the species level, on the basis of cultured material of a large number of species. Multiple DNA marker analyses resolved detailed and robust phylogenetic relationships within the genus and demonstrated the taxonomic and phylogenetic significance of IMOW. In addition, they supported the taxonomic decisions based on differences in oospore morphology, suggesting that an integrated approach, involving both SEM studies of the EMOW and IMOW and multiple DNA marker analyses, is appropriate to address problems at lower taxonomic levels within the genus, as well as to construct a natural taxonomic system for the genus. In this paper, recent morphological and molecular phylogenetic studies are reviewed and recent improvements in taxonomy of Nitella are summarized. Moreover, the evolution of morphological features and phylogenetic relationships within Nitella are discussed, focusing especially on oospore morphology.     

轮藻植物在澳大利亚的重新发现之探密

澳大利亚轮藻植物研究历史悠久,迄今约有95种被描记。在Wood(1972)对澳大利亚轮藻植物的修订研究中,一些种因为标本遗失或已损坏而未包括在内,其中有的种近年来又被重新发现。本文重点介绍Nitella hookeri A．Br．var．arthroglochin A．Br．,Lychnothamnus barbatus(Meyen)Leonh．和Nitella partita Nordst．的发现过程及其产地生态环境,探讨了季节性湿地对轮藻植物的保护意义。N．hookeri var．arthroglochin早在1854年就发现于澳大利亚,并于1887年再次作为澳大利亚特有物种而被记录,然而从此销声匿迹,直至1989年才再度问世,它重新出现的地点为新南威尔士州高海拔花岗岩风化土壤地区的季节性溪流中。L．barbatus则为R．D．Wood首次发现于1960年,嗣后一再搜寻并无踪迹,直到1996年才于昆士兰东南地区亚热带阵发性溪流中被再次发现。昆士兰中部干旱地区1889年一度见到的N．partita,也是近一百年后才在新南威尔士州西北干旱地区的季节性湿地再次发现。     

Some New Taxa and New Records of Charophyta from Guizhou

Guizhou is situated in the southwestern China and is very rich in algae However, our present knowledge of the Charophytes is scanty. Over 400 specimens were collected from 22 counties or cities and from them 41 species, 2 subspecies, 3 varieties were found. In addition to previously known species of this region, Nitella rasilis, N. paludosa, N. pseudopapillata and N. guizhouensis are new species, N. mirabilis var. libera is new variety, and N. penicillata, Chara burmanica, C. vulgaris var. gymnophylla are new records for China. In this paper, only the new taxa are reported.     

Some New Taxa of Charophyta from Guangxi

Guangxi, Situated in the southern border area of China, is extremely rich in Charophytes. In this paper, however, reported are only new species and new varieties. Among the new taxa, Nitella haplodactyla has only one dactyl on the fertile branchlet, N. brachyclema and N. rarissima are provided with more than 4-celled dactyls, the fertile branchlet of N. pseudoflabellata var. tetradynana has tetradynamous rays, and Chara piniformis is characterized by thehaplostichous cortex, long spinecells, and rudimentary stipulodes.     

Report on Charophytes from rice fields in northern Italy including the alien species Chara fibrosa ssp. benthamii

The paper describes the discovery in rice fields of northern Italy of three species of Charophytes rarely reported in Italy, Chara fibrosa ssp. benthamii, a tropical taxon not native to the European Charophyte Flora, previously recorded in Italy only once, in the nineteenth century, Nitella translucens and N. mucronata.     

中国轮藻植物区系研究

中国轮藻植物有13种分布区类型,其中以中国特有分布占绝对优势,其它分布类型所占比例较低,说明中国轮藻植物与其它地区轮藻植物联系较少。丽藻属有10种分布区类型,缺少温带特性的分布区类型,如北温带分布、旧世界温带分布,其它分布区类型显示丽藻属主要分布在热带和亚热带地区,而轮藻属有13种分布区类型,温带特性的分布区类型所占比例较高,如旧世界温带分布,其它分布区类型显示轮藻属主要分布在温带地区。     

Oospore variation in <Emphasis Type="Italic">Nitella gracilis</Emphasis> and <Emphasis Type="Italic">Nitella mucronata</Emphasis> (Charales,Charophyceae) from Poland

The determination of the members of Charales (Charophyceae) is not easy. The main reason of this is a wide range of variation in vegetative characters within most of the species. Many features such as the extent of branchlet cortication, the degree of incrustation, length and number of bract cells, spine cells, stipulodes, diameter of the main axis and oospore size and color do not have universal taxonomic significance. In similar, many Nitella species characters such as: general habitus, branchlets and presence of the top segment (mucro), are helpful in determination, however they are often not developed. In this case, the features of oospore wall ornamentation revealed by light and scanning microscopy can be important taxonomic characters of the Charales. The present study shows interspecific variations of the oospore in two Nitella species from Poland which can be helpful in correct determination of both species. Some of the oospore features like number of striae and fossa width can not be used, as they appeared statistically unimportant, and cannot be used in distinguishing between both species. The presented results are the first detailed report of oospore wall ornamentation pattern from Poland for the species studied. Oospore features are presented in detail on the background of some additional tips and among them particularly: length and width of the oospore, ISI idex, width of fossa, width of striae and number of striae.     

福建冬青属二新种

本文描述了发现于福建的冬青科冬青属2新种——泰宁冬青Ilex tainingensis G. S. He和南平冬青I. nanpingensis G. S. He，并分别说明两者与其他近缘种的区别要点。泰宁冬青与太平山冬青I. sugerokii Maxim.的区别在于前种小枝被毛，无棱槽，叶片宽卵圆形，花淡紫色，分核表面具细条纹，背后中部有一凹槽。南平冬青与拟榕叶冬青I. subficoidea S. Y. Hu区别在于前种果为椭圆形，较大，表面光滑无腺点，果梗长于1 cm，每分核上端有2尖角，均可以区别。     

Oospore dimensions and wall ornamentation patterns in Swedish charophytes

The ultrastructural features of oospore wall ornamentation patterns revealed by scanning electron microscopy are important taxonomic characters of the Charales. The present study shows inter-and intrapecific variations in 19 species of the genera Chara, Lamprohamnium, Nitella and Tolypella. This is the first time that the oospore wall ornamentation of Swedish Charales has been documented in detail. In the studied Chara species the ornamentation within species was variable, and partly overlapping between species, but only between closely related species. In contrast, the Nitella species showed distinct differences in ornamentation patterns between species, although the same patterns can be found in different species. This study presents for the first time SEM images of the species Chara rudis (pustular ornamentation), Nitella opaca (pitted ornamentation) and Nitella wahlbergiana (anastomosing network ornamentation). The ornamentation pattern in the Nordic species TV. wahlbergiana , supports its separation from Nitella mucronata which has a reticulate ornamentation. The relationship between length and width of the oospores is also of taxonomic significance. Nitella and Tolypella oospores are roundish, whereas those of Chara and Lamprothamnium are elongate. The extent to which environmental and genetic factors can affect oospore size and shape within a species are still unknown, but in the present study both ornamentation pattern and size provided evidence for the distinction between Chara globularis and Chara aspera. Some further taxonomic problems in the Charales are discussed in the light of the results of this study.     

THE ASSOCIATION OF ROSETTE AND GLOBULE TERMINAL COMPLEXES WITH CELLULOSE MICROFIBRIL ASSEMBLY IN NITELLA TRANSLUCENS VAR. AXILLARIS (CHAROPHYCEAE)1,2

A freeze-fracture investigation of the putative cellulose synthesizing complex (terminal complex) morphology in Nitella translucens var. axillaris (A. Br.) R.D.W. internodal cells revealed single solitary EF globules and PF rosettes on the plasma membrane. The average density of rosettes in elongating internodal cells was 5.6 μm^?2 with slight spatial variation observed. In only three other algal genera (all zygnematalean) have rosette / globule terminal complexes been observed, while this characteristic is common to all vascular plants and one moss thus far investigated. This evidence strongly suggests that the rosette type of terminal complex morphology is an additional characteristic of charophycean algae and lends further support to the hypothesis that this group of algae represents the evolutionary line that gave rise to vascular plants. Observations were also made from the freeze-fracture of Nitella internodal cells concerning the orientation of cell wall microfibrils and cytoskeletal elements near the plasma membrane. The pattern of microfibril orientation in growing internodal cells is initially transverse to the cell long axis, becoming progressively axial presumably due to the strain of elongation. In mature internodal cells, the pattern of microfibril orientation is helicoidal. Microtubules appressed to the inner surface of the plasma membrane are oriented parallel to the most recently formed microfibrils in elongating and mature internodal cells.     

ACROSYMPHYTON FIRMUM SP. NOV. (RHODOPHYTA,CRYPTONEMIALES), A NEW SUBTIDAL RED ALGA FROM NEW ZEALAND; DEVELOPMENTAL MORPHOLOGY AND DISTRIBUTION OF THE GAMETOPHYTE1

Acrosymphyton firmum sp. nov., is described from the northeastern coast of North 1., New Zealand. Gametophytes are spring–summer annuals which grow subtidally on cobbles. Thalli are uniaxial; each axial cell bears a whorl of four indeterminate and one determinate branchlets. Indeterminate branchlets are alternately arranged giving the thallus a distichous and feather-like appearance. Numerous corticating rhizoidal filaments are produced from the periaxial and lower whorl branchlet cells. These rhizoids entwine and obscure the main axis as the thallus develops until in the mature plant the axes have a firm consistency and lubricous texture. The carpogonial branch bearing short lateral filaments and auxiliary cell branch with terminal auxiliary cell place this new species in the genus Acrosymphyton Sjöstedt. Of the three described species in the genus, A. firmum is most similar to A. taylori. This is the first report of the genus Acrosymphyton and the only confirmed report of the family Dumontiaceae in New Zealand waters.     

ANNUAL GERMINATION WINFOW IN OOSPORES OF NITELLA FURCATA (CHAROPHYCEAE)1

Oospores of Nitella furcata subsp. megacarpa (Allen emend. Wood) were collected from an oospore bank in the sediments of Lake George, New York. Incubated at constant temperatures, all or nearly all of the oospores germinated when exposed to a brief pulse of red light when the annual window of germinability was open. The window seems related to the annual cycle of sediment temperatures. It is open in spring and closes wit the onset of a secondary dormacncy in the summer. Oospores in storage follow a parallel path if held at 18°C, a summer equivalent temperature; the window remains open indefinitely if the oospores are held at 4°C. Attention is drawn to the similarity if the cyclic window of germinability in seeds of summer annuals and oospores of N. furcata.     

A new species of Cestrum (Solanaceae) from the Cordillera de Mérida, Venezuela

A new species ofCestrum from the Cordillera de Mérida in Trujillo state is described and illustrated.Cestrum darcyanum, morphologically similar toC. microcalyx Francey, is distinguished by dendritic pubescence on its branchlets and leaves, larger corolla, stamens distended and geniculate above their point of adnation to the corolla, and larger calyx. A key is provided for species of VenezuelanCestrum possessing dendritic pubescence.     

Arsenic metabolism in freshwater and terrestrial plants

Freshwater and terrestrial plants differ markedly in their ability to metabolize arsenate. In experiments with higher terrestrial plants, e.g. tomato, Lycopersicon esculentum Mill. cv. Better boy, ⁷⁴As-arsenate was readily taken up and reduced to arsenite. Methylation and reduction to methanearsonic acid, methanearsinic acid (indicated for the first time) and dimethylarsinic acid were apparent only in phosphate deficient plants. Lower and higher freshwater plants, e.g. Nitella tenuissima Kütz. and Lemna minima Phill., not only methylated arsenic but also produced considerable amounts of an arsoniumphospholipid previously identified in marine algae. These differences indicate that freshwater but not terrestrial plants have evolved mechanisms for rapid detoxication of arsenate, arsenite and other toxic arsenic species.     

Oscillations of membrane potential during inhibition of cytoplasmic streaming in Characean internodes

Oscillatory changes in electrical parameters of cells of Nitellopsis obtusa (Desv. in Lois) J. Gr. and Nitella flexilis f. Atkahensis R. D. W., particularly in the membrane potential, were investigated with external Ag/AgCl electrodes. Three main types of oscillations were observed. The measurements were carried out on 30 cells with the application of an inhibitor of cytoplasmic streaming (procaine) and revealed that there was no direct correlation between cytoplasmic streaming and oscillations in the membrane potential.