bluuebunny/crossref_metadata_2025_split huggingface dataset:
An enumeration of the orchids of Northwestern Himalaya
Authors: Seidenfaden Gunnar , Arora C. M. 
Published: March 2008

An alphabetic enumeration of the species of orchids recorded from Northwestern Himalaya is supplied. While the classical work by Duthie listed a number of about 173 species, later finds bring this number up to about 250 species of which 24 are here recorded for the first time. This includes two proposed new species Eria occidentals Seid. and Flickingeria hesperis Seid. An attempt has been made to bring the nomenclature in accordance with modern concepts and rules, one new combination, Aorchis roborovskii (Maxim.) Seid., is proposed.A plea is made for the establishment of strictly guarded reservations in order to conserve the remains of the fast dwindling orchid flora.
Catila and Onira, two new genera of South American Iridaceae
Authors: Ravenna Pierfelice 
Published: March 2008

Two new genera of Iridaceae–Tigridieae, namely Catila and Onira, are described. The former is based on Catila amabilis Ravenna, a new species; the latter on Herbertia unguiculata Baker. Both belong to the flora of south–eastern South America.The relationships of Catila with Cypella Herb, and Calydorea Herb., two genera so far considered as belonging respectively to the tribes Tigridieae, and Sisyrinchieae, are emphasized. Moreover, its inflorescence, seedling, and pollen morphology, as well as chromosome number (2n = 14), are described. Onira, the second genus here proposed is considered as related to Cypella, Sympa Rav., and Kelissa Rav., and less closely also to Catila.The tribes Tigridieae and Sisyrinchieae are surveyed and discussed, especially in relation to the systematics of the genera concerned. In this connection, the “cypel–loid” character of the androecium and gynoecium of Cipura Aubl., and the unrealistic concepts on which previous authors based their descriptions of this genus, are disclosed. As a result, tribe Tigridieae is emended, in order to include exclusively the American genera bearing a tunicated bulb covered by membranous, or at least not fibrous coats.
Reproduction in seagrasses: pollen wall morphogenesis in Amphibolis antarctica and wall structure in filiform grains
Authors: Pettitt J. M. , McConchie C. A. , Ducker S. C. , Knox R. B. 
Published: March 2008

The pre–meiotic anther of the marine angiosperm Amphibolis antarctica contains microsporocytes and sterile cells. The microsporocytes divide conventionally to produce tetrads, but the sterile cells degenerate and contribute to the future pe–riplasmodium. Each tetrad of young microspores is contained within a vesicle defined by a membrane. After release from the tetrad, the microspores increase in length and rapidly become filiform. The microspore nucleus soon divides and partitioning of the cytoplasm delimits the generative cell from the vegetative cell of the binucleate pollen grain. The division and the early pollen growth occurs while the grains are segregated within vesicles in the periplasmodium. These compartments, established at microspore release, remain structurally intact throughout the vacuolate period of pollen development, when pollen wall assembly begins. This process is initiated as particles migrate from the inner face of the vesicle membrane into the lumen of the vesicle and microfibrillar elements form between adjacent particles. The particles and microfibrils form a loose, three–dimensional network. The vesicle membrane then disappears and the binuclate grains become immersed in the tapetal residuum. Additional wall components are now deposited upon the primary fibrillar stratum. Short lamellae, resembling fragments of membrane, frequently associated with electron–opaque globuli, are found intermixed with the surface microfibrils. Apparently, granular material originating in the degenerating periplasmodium may be the precursor of the globuli, and contact with the lamellae brings about an alteration in state. At this stage the pollen wall is resolved as two distinct fibrillar strata and the lamellae and globuli are incorporated as inclusions into the superficial zone of the outer stratum. The mature pollen wall exhibits faint stratification and the presence of the subsurface inclusions is readily demonstrated in germinating grains by section staining with phosphotungstic acid.The pollen wall in A. antarctica is compared with that in filiform grains of other seagrasses.
Experimental field studies on the ecology of Scytosiphon lomentaria (Fucophyceae, Scytosiphonales) in Denmark
Authors: Kristiansen Aase 
Published: March 2008

Experimental field studies on the ecology of Scytosiphon lomentaria have been carried out in two types of Danish localities during 1981 and 1982: a sheltered and shallow fiord with a scanty vegetation, and a more exposed locality with a rather dense vegetation. Colonization experiments have been made by depositing artificial substrates several times during spring and autumn in both localities. These showed that Scytosiphon lomentaria is able to colonize and develop, i.e. produce prostrate systems with erect thalli under long–day as well as under short–day conditions, and even to become fertile. Transplantation experiments between the two localities have been made in both directions in spring and autumn. These proved that the transplanted prostrate systems are able to sprout into erect thalli in accordance with the normal seasonal distribution in the new locality. The difference in seasonal occurrence is thus environmentally determined.Quantitative culture studies have confirmed that erect thalli develop independently of daylength.
Vegetational changes on two eroding banks of a short‐term regulated river reservoir in northern Sweden
Authors: Grelsson Gunnel 
Published: March 2008

This study deals with the vegetational changes and the course of erosion on two types of river banks bordering a river reservoir, in northern Sweden. The water‐level has been short‐term regulated since 1961, with an amplitude of about 3 m in the uppermost reaches of the reservoir and about 1 m furthest downstream. The pattern of regulation includes both a weekly and a daily rhythm. The banks of the river reservoir have been cut in fine‐grained sediments. The two sites selected for study were (1) a formerly littoral area (2) a formerly dry‐land area. Percentage cover and number of shoots were determined annually within belt transects subdivided into 10 times 10 cm quadrats, during the period 1977–1981.The course of bank erosion was initiated and mainly continued by water movements. In the formerly littoral area, erosion proceeded only slowly, whereas in the formerly dry‐land area erosion was rapid and the bank was continuously being undercut, leading to the formation of an overhanging mat of vegetation. As erosion progressed, this overhanging mat split up and slumped down into the reservoir. The vegetational changes on the overhang were considerable, while the terrace maintained a more stable vegetation cover. In the long‐term, the composition of the vegetation on the former littoral river‐bank remained more stable than on that cut into the former dry‐land area. The break‐up of the vegetation cover on the overhang also initiated secondary vegetational successions on the exposed soil. Considerable differences in the vegetation cover were also recorded from one year to the next. These differences were considered to be mainly due to differences in the rate and local course of erosion. Annual differences in the rhythm and/or amplitude of the fluctuations in water‐level were considered to be less important in this respect.
Scalesia gordilloi sp. nov. (Asteraceae) from the Galápagos Islands, Ecuador
Authors: Hamann Ole , Wium‐Andersen Søren 
Published: March 2008

Scalesia gordilloi is described from Isla San Cristóbal, Galápagos Islands, Ecuador. It has a restricted, local distribution along the south coast in arid zone vegetation. It is related to S. divisa Anderss. and S. incisa Hook. f. The taxonomic relationships of S. gordilloi are discussed.Resumen Scalesia gordilloi está descrita desde la isla San Cristóbal, Islas Galápagos, Ecuador. Tiene una distribución limitada y local al lado de la costa sur en la zona vegetal árida. Está relacionada a S. divisa Anderss. y S. incisa Hook. f. Se discute la taxonomía de S. gordilloi.
Gynoecial morphology and funicular germination plugs in the Nolanaceae
Authors: Bondeson Wolmar E. 
Published: March 2008

In Nolana humifusa (Gouan) Johnst. and N. paradoxa Lindl, five carpel primordia unite by their thin margins to form the gynoecium wall. An ovule primordium is initiated in each of a maximum of six depressions, formed in the adaxial surface of each carpel primordium. The depressions become deeper, each developing into a duct that ends in an ovule chamber, which is a uniovulate locellus. The locellus is delimited by a ventral carpellary epidermis except at its lower adaxial part, where the ovule is invaginated on a short funicle from its own placenta.Periclinal cell divisions in the subsurface layers of the floral apex form a receptacular column, which grows in continuity with the lower adaxial parts of the carpel primordia; the upper parts of the carpel primordia face the five‐radiate “common cavity” inside the gynoecium wall. At anthesis this cavity is filled with stylar and ovarian transmitting tissue. The latter forms five “wings” that downward are continuous with wings of the receptacular column and which together with them radiate between the five carpels. True septa are not formed.In N. humifusa a plurilocellate mericarp originates from each carpel primordium. In N. paradoxa longitudinal unilocellate portions of each plurilocellate carpel primordium develop independently into “carpel‐lobes”, the bulging lower parts of which mature into unilocellate mericarps. In both species the funicle develops into a germination plug.The locellar organization described is a common feature of the Nolanaceae. The formation of invariably uniovulate placentae in pluriovulate carpels is the basic innovation of the family.
Flowering and fruiting phenology in the apomictic blackberry, Rubus nessensis (Rosaceae)
Authors: Nybom Hilde 
Published: March 2008

Five stands of an apomictic blackberry, Rubus nessensis, were studied. Biennial shoots flower and fruit in their second year on lateral branches developed from axillary buds. Most premature death of reproductive units occurs by withering of entire laterals, presumably due to damage by frost during the preceeding autumn or winter. Health status of the floricane, assessed as percentage live axillary buds in the spring, was positively correlated with the reproduction parameters. Shoot height as well, is positively correlated with number of flower buds and flowers produced on each lateral but, however, negatively correlated with number of berries, probably because tall shoots tend to suffer more damage by frost which seriously afflicts the vascular tissues of the laterals.The position of the axillary buds on the shoot affects survival and degree of fertility, those situated medially greatly surpassing apical and basal ones.
Leaf anatomy of alpine plants as related to altitudinal stress
Authors: Codignola A. , Maffei M. , Fusconi A. , Fieschi M. 
Published: March 2008

Alopecurus gerardi, Poa alpina, and Carex curvula are spontaneous, perennial forage plants distributed in the high elevation (2300–3200 m) pasture lands of Piedmont and Valle d'Aosta (Italy). Sedum atratum is an annual succulent which grows at elevations up to 3200 m. The three monocotyledons have, in comparison with corresponding plants from the low‐land, peculiar organographic and anatomic structures such as curling leaf lamina, vascular bundle sheath layer with chloroplasts arranged in a centrifugal fashion, low stomatal density (stomata number/cm2: upper epidermis x̄= 0–11.9; lower epidermis x̄= 7.66–11.55), thick cuticles, as well as higher values of S (H2O; g/dm2; x̄= 0.6–0.32), Sm (H2O g/mg Chi.; x̄= 0.11–0.16), SLW (g f. wt/dm2; x̄= 0.86–1.36), but lower SLA values (cm2/g f. wt; x̄= 75.07–116.77). All these data are correlated to water stress. Even though the leaf lamina anatomy possesses some features typical of C4 plants, the presence of starch grains in the mesophyll chloroplasts indicates that these plants are probably C3 ones.In spite of high values of thylacoid grana/thylacoid intergrana ratios, typical of shade plants (mesophyll chloroplasts: x̄ up to 3.81; bundle sheath chloroplasts: x̄ up to 5.3), and Chi a/Chl b ratios (x̄ up to 4.23 in C. curvula), the apparent absence of peroxisomes seem to indicate a very efficient dark phase of photosynthesis. S. atratum, in comparison with the typical CAM succulents, which live in dryer and warmer habitats, has a higher values of stomatal density (upper epidermis, x̄= 2.59; lower epidermis, x̄= 3.15) and of SLA (x̄= 24.98), but lower S (x̄= 3.83), Sm (x̄= 1.19) and SLW (x̄= 4.15).
Alkaloid chemotaxonomy of Nordic Papaver sect. Scapiflora (Papaveraceae)
Authors: Folkestad Kirsten , Høiland Klaus , Paulsen Berit Smestad , Malterud Karl Egil 
Published: March 2008

A chemotaxonomic study of the Nordic Papaver species belonging to the Scapiflora group has been carried out by means of gas chromatography (GC), mass spectro‐graphy (MS), and thin layer chromatography (TLC). The data obtained were analysed by the aid of hard and fuzzy clustering. Of the alkaloids identified, protopine and allocryptopine were found in all species investigated (i.e. Papaver radicaium ‐including all subspecies ‐ P. dahlianum, P. lapponicum, and P. laesiadianum). Protopine and allocryptopine were the only alkaloids found in P. dahlianum, P. lapponicum, and P. laesiadianum. In addition O‐methylthalisopavine was found in all investigated subspecies of P. radicatum; reframine in P. radicatum sspp. ovatilobum, gjaerevollii, groevudalense, intermedium, oeksendalense, radicatum, relictum, and subglobosum; reframidine in ssp. hyperboreum; cryptopine in sspp. ovatilobum, gjaerevollii, groevudalense, relictum, subglobosum, macrostigma, and hyperboreum; muramine in sspp. macrostigma and hyperboreum; and amurine in sspp. relictum and subglobosum.These chemotaxonomic results confirm the systematics of the Nordic Papavers of the sect. Scapiflora introduced by Knaben who based the taxonomy on morphological and cytological characteristics. Moreover, the content of alkaloids in the different isolated Nordic Papaver populations may be of plant geographical importance. There are, for instance, a marked chemical difference between all the South Norwegian subspecies of P. radicatum and the North Norwegian P. radicatum ssp. subglobosum on one hand and the rest of the North Norwegian subspecies on the other.
Glandular trichomes of Humulus lupulus var. Brewer's Gold: Ontogeny and histochemical characterization of the secretion
Authors: Oliveira M. Margarida , Salomk M. , Pais S. 
Published: March 2008

Leaves of Humulus lupulus possess two types of glandular trichomes: ‐ peltate (lupulin) and bulbous.Peltate trichomes are formed from a protodermal cell by two anticlinal divisions in perpendicular planes, followed by two periclinal ones that give rise to the initials of the head cells, the basal and the stalk cells. Head cells divide successively in radial and irregular planes. Fully developed peltate trichomes are built of a glandular head consisting of 30 to 72 cells, four stalk cells and four basal cells.Bulbous trichomes are also formed from a protodermal cell by an anticlinal division followed by two periclinal ones that produce the initials of the glandular head cells, and the basal and stalk cells. Fully developed bulbous trichomes consist of four (occasionally eight) head glandular cells, two stalk cells and two basal cells.The density of peltate trichomes decreases with the expansion of the leaves.Both peltate and bulbous trichomes secrete essential oils. Peltate trichomes are the preferential site for the synthesis of bitter resins. Tannic acids could not be detected histochemically either in peltate or in bulbous trichomes. Both types of trichomes produce secretion that accumulates in the subcuticular space, being released, in the case of bulbous trichomes, by rupture of the cuticle.
Inflorescence morphology of some South American Anacardiaceae and the possible phylogenetic trends
Authors: Barfod Anders 
Published: March 2008

Barfod, A. 1988. Inflorescence morphology of some South American Anacardiaceae and the possible phylogenetic trends. ‐ Nord. J. Bot. 8: 3–11. Copenhagen. ISSN 0107–055X.The inflorescences of 15 native and one introduced species of South American Anacardiaceae belonging to the genera Anacardium, Loxopterygium, Mangifera, Mauria, Mosquitoxylon, Schinus, Spondias, Tapirira and Toxicodendron are described according to the terminology of Troll and coworkers. The tribal divisions in the Anacardiaceae are supported by the inflorescence morphology. Tribe Spondia‐deae has paniculate inflorescences whereas tribe Anacardieae and tribe Rhoeae both have thyrsoids. Toxicodendron is exceptional for the tribe Rhoeae having axillary panicles. Thyrosids are hypothesized derived from panicles by a two step process including neoteny and enriching by cymose branching.
The zoospore of Pseudoperonospora cubensis, the causal agent of cucurbit downy mildew
Authors: Lange Lene , Edén Ulla , Olson Lauritz W. 
Published: March 2008

The zoospore of Pseudosporonospora cubensis is typical of the secondary zoospore of the Peronosporales. The reniform zoospore contains a central nucleus with a prominent beak‐like extension to the kinetosomes on the lateral side of the spore in the groove region. “Fuzzy” vesicles derived from dictyosomes surround and fuse with the contractile vacuole. Mitochondria and microbodies are located in the peripheral cytoplasm of the zoospore but the latter are confined to the groove region of the spore. The microbodies usually contain a laminate inclusion and the microbodies are not in a fixed position in relation to the peripheral cisternae. Neither a microbody‐lipid body complex nor a “U‐body” were observed.The kinetosomes of the spore are almost perpendicular to each other at the distal end of the beak‐like extension of the nucleus. A complex system of cytoplasmic microtu‐bules flare out from the kinetosomes to surround the nucleus and bundles of cytoplasmic microtubules extend under the plasmalemma of the spore. The zoospore contain numerous vesicles with osmiophilic inclusions which are finely striated; these are the so‐called finger‐print vesicles.
A hay meadow in western Norway‐changes in the course of a growing season
Authors: Losvik M. H. 
Published: March 2008

Interference of management with groups of species/single species in a hay meadow is studied in a pilot project. Plant species are recorded 3 times during growing season from 10 permanent plots at intervals along 2 transects crossing the meadow. Hult‐Sernander‐Du Rietz scale is used for estimating cover, and phenological phases are estimated according to Dierschke.The hay meadow is lightly fertilized in spring, mown once late in July and grazed lightly by calves in autumn. Until 7–8 years ago the meadow was more heavily grazed by sheep both in spring and autumn.50 species are recorded, 44 within the permanent plots, 33 are indicators of agricultural management, 21 are indicators of traditional management, and 24 are adapted to grazing. The meadow belongs to Cardamino pratensis‐Conopodietum majoris, subas‐sociation campanuletosum. Luzula campestre, Campanula rotundifolia, Potentilla erecta, Hypochoeris radicata and Trifolium repens vary little in cover throughout the summer. Anthoxanthum odoratum, Leucanthemum vulgare, Trifolium pratense and Agrostis capillaris have a higher cover just before mowing than afterwards. Conopodium majus is not present above ground at all in August. Rumex acetosa and Achillea millefolium have their highest cover values in August. The time of flowering varied. At the spring analysis, Ajuga pyramidalis, Anthoxantum odoratum, Luzula campestre and Plantago lanceolata flowered. The main flowering took place at the end of June, when 20 species flowered. In August the flowers of Leontodon autumnalis, Hypochoeris radicata, Potentilla erecta and Hieracium vulgatum characterized the meadow. Several hypothesis and proposals for testing of the hypothesis are put forward.
Silica‐scaled chrysophytes from West Greenland: Disko Island and the Søndre Strømfjord region
Authors: Kristiansen Jørgen 
Published: March 2008

The flora of silica‐scaled chrysophytes (Chrysophyceae and Synurophyceae) is known from two previous investigations in southern Greenland, from Narssaq (61°N) and Nuuk (64°N).In connection with a course in Arctic Biology 25.7.‐20.8 1990 chrysophyte samples were obtained from altogether 53 localities, 41 from the Godhavn region in Disko Island (69°N) and 12 from S0ndre Str0mfjord (67°N). The localities were lakes, ponds and puddles, on basalt or an acid bedrock. Fixed samples were examined by EM, and altogether twenty species were identified by their silica scales. Eight of these were new to Greenland, viz. Spiniferomonas silverensis, Mallomonas acaroides, M. alpina, M. crassisquama (previous records proved to belong to M. duerrschmidliae), M. oviformis, M. paludosa, M. tonsurata, and Synura mammillosa. The composition of the flora is discussed from ecological and biogeographic viewpoints.
Sex ratio, reproductive investment and flowering phenology in dioecious Rhamnus alaternus (Rhamnaceae)
Authors: Guitihn Javier 
Published: March 2008

Guitián, J. 1995. Sex ratio, reproductive investment and flowering phenology in dioeciousRhamnus alaternus(Rhamnaceae). ‐ Nord. J. Bot. 15: 139–143. Copenhagen. ISSN 0107–055X.During 1992 and 1993 I investigated the reproductive biology of the dioecious Mediterranean shrubRhamnus alaternusin a population in the northwest Iberian Peninsula. Reproductive investment was estimated as the mean total dry weight of reproductive organs per branch tip. I also estimated number of flowers produced per plant and population sex ratio, and investigated the spatial distribution of the sexes and flowering phenology. The sex ratio was 1:1, and the spatial distribution of the sexes was random. Male plants produced 2.6 times more flowers than female plants, but the overall reproductive investment by females was 5‐ to 9‐fold higher. In both years of study, male plants commenced flowering first. The male and female flowering peaks coincided closely (in late March) in both years. The results of this study suggest that male and femaleR. alaternusdiffer most notably in the amount of resources allocated to reproduction.
Six new species of ferns (Polypodiopsida) from Ecuador
Authors: Moran Robbin C. , Bllgaard Benjamin 
Published: March 2008

Moran, R.C. & Øllgaard, B. 1995. Six new species of ferns (Polypodiopsida) from Ecuador. ‐ Nord. J. Bot. 15: 177–185. Copenhagen. ISSN 0107–055X.The following species of ferns from Ecuador are described as new:Blechnum mono‐morphum. Bolbitis riparia, Hecistopteris pinnatifida, Hymenophyllum hemidimorphum, Polypodium latissimum, andSaccoloma laxum.
Seed set and germination in crosses within and between two geographically isolated small populations of Saxifraga hirculus in Denmark
Authors: Dahlgaard Jesper , Warncke Esbern 
Published: March 2008

Dahlgaard, J. & Warncke, E. 1995. Seed set and germination in crosses within and between two geographically isolated small populations of Saxifraga hirculus in Denmark. ‐ Nord. J. Bot. 15: 337–341. Copenhagen. ISSN 0107–055X.Seed set and germination were studied in two geographically isolated populations of Saxifraga hirculus in Jutland, Denmark. The size of the populations differed, but both were assumed to exhibit significant genetic homogeneity and inbreeding due to (1) small population size (2) limited pollen flow and seed dispersal and (3) absence of gene flow between populations. Crosses within populations, as well as reciprocal crosses between populations, were carried out in the field. Seed number, proportion of developing seeds, germination percent, and germination rate were found to be greater for crosses between populations than for crosses within populations. Variation in seed size was found to be larger for maternal plants from the smaller population.