Studies of the green alga Percursaria dawsonii (=Blidingia dawsonii comb. nov., Kornmanniaceae, Ulvales) in British Columbia

We cultured and sequenced newly collected material of Percursaria dawsonii Hollenberg et I. A. Abbott, a poorly known epibiont of limpets found along the west coast of North America. Zoospores, parthenogametes, and zygotes exhibited empty‐spore germination, which produced a prostrate system that expanded by stolon‐like development. A dense carpet of initially uniseriate filaments arose from the prostrate system. These upright filaments soon became biseriate proximally and pluriseriate distally, where they were flat, twisted and distromatic for approximately four‐fifths of their length and rarely became hollow in larger individuals. These fronds became fertile distally and released quadriflagellate zoospores and/or biflagellate isogametes. Individual gametophytic fronds were dioecious, and alternated with isomorphic sporophytic fronds. The gametes moved rapidly and often exhibited an unusual side‐to‐side vibration that made them appear like winged insects. Comparisons of 18S rRNA gene and ITS sequences indicated that P. dawsonii should be included in the genus Blidingia, family Kornmanniaceae.     

Life history of Acrosiphonia (Codiolales, Chlorophyta) in southwestern British Columbia, Canada

This study establishes the phenology of the alternate life history phases of the green alga Acrosiphonia in British Columbia, Canada. Free-living, filamentous plants are seasonal, March-July, with peak percent cover (10%) in April. Plants are fertile immediately after establishment. The unicells, previously identified as Chlorochytrium inclusum and Codiolum petrocelidis, are the sporophyte phase of Acrosiphonia. 'Chlorochytrium,' spherical and 160-280 μm in diameter, colonizes the foliose red alga Mazzaella splendens 1 mo after filamentous Acrosiphonia plants appear. Maximum density (53 'Chlorochytrium' cells/cm(2) of blade) was recorded in May. 'Codiolum,' on the other hand, is stalked (the vesicle measures 150 × 50 μm) and colonizes the red algal crust Petrocelis. Peak density (22?400 'Codiolum' cells/cm(2) of crust) was recorded 2 mo after 'Chlorochytrium' density peaked. The endophytes survive high summer temperatures, which correlate with death of the free-living plants, and overwinter in their hosts. Zoospore release in late winter corresponds to decreased host abundance, suggesting the endophytes have evolved a strategy whereby duration in the host is synchronized with host seasonality. A bet-hedging strategy is proposed for Acrosiphonia's life history: two morphologically different phases have adapted to a seasonally variable environment, with the sporophyte phase capable of colonizing two different hosts.     

Blidingia ramifera stat. nov. (Chlorophyta): a new marine alga for eastern North America

Blidingia minima var. ramifera is reported for the first time in eastern North America. It occurs in the Gulf of St. Lawrence, Nova Scotia and in Maine. In the estuary of the West and Rights Rivers (Antigonish Harbour, Nova Scotia) it is the most common intertidal alga and during its maximum growth period (June-August) covers 75–90% of the intertidal zone for several km of shoreline at the mouth of the Rights River. In culture, spore germination and early development were typical of the taxon as described from Europe. The taxon is raised to specific status as Blidingia ramifera stat. nov. Blidingia subsalsa is confirmed from New England based on observations of spore germination in plants from Maine and Connecticut.     

The life history ofAcrochaete wittrockii (Ulvellaceae,Chlorophyta)

Acrochaete wittrockii (Wille) Nielsen is a heteromorphic diplohaplont. The haplophase consists of isomorphic, dioecious filamentous epiphytes on brown algae. Several generations follow each other by triflagellate zoospores from spring to early summer. By late summer and throughout autumn, quadriflagellate zoopores are produced by the epiphytic thalli; they give rise to male and female gametophytes of a globular, pseudoparenchymatic appearance in culture. The gametophytes produce anisogamic biflagellate gametes which, after gametic union, develop into diploid unicellular sporophytes. After 6–7 days, the sporophyte produces triflagellate zoospores, repeating the life history when germinating on brown algal hosts. Alternatively, triflagellate zoospores which settle on the bottom of petri dishes, develop into unicellular, autonomous sporangial plants. Their triflagellate spores repeat the epiphytic stage on brown algal hosts, or the sporangial plant cycle on non-living substrate, respectively.     

Life history and taxonomy ofCricosphaera roscoffensis var.haptonemofera,var. nov. (class prymnesiophyceae) from the pacific

A new coccolithophoridCricosphaera roscoffensis var.haptonemofera is described by means of electron microscopy and with the aid of laboratory culture. The living specimens, which were in the motile phase, were collected in Okinawa, a subtropical region in Japan, and a unialgal culture was established in the laboratory. The life history was observed, starting from the motile cells. The life history consists of two phases: the motile phase and the benthic filamentous phase. The former is unicellular and presumably a diploid sporophyte, whereas the latter is similar to an alga previously known as “Apistonema submarinum” described by Dangeard (1934), and probably a haploid gametophyte. The motile cells bear two acronematic flagella and one short haptonema. The scales attached on the surface of the motile cells are of two kinds: one is an organic thin scale, and the other is a cricolith, a kind of coccolith, the latter being structurally almost identical with that ofCricosphaera roscoffensis studied by Gayral and Fresnel (1976). Because this species has neither haptonema nor a benthic filamentous phase, we propose, at present, to treat this alga as a new taxon at the rank of infraspecies, naming itCricosphaera roscoffensis var.haptonemofera Inouye et Chihara.     

Production of bioflavor by regeneration from protoplasts of Ulva pertusa (Ulvales,Chlorophyta)

Protoplasts were isolated from thalli of Ulva pertusa using a mixed enzyme solution of 2.0% Cellulase Onozuka R-10, 2.0% Macerozyme R-10, and 2.0% Driselase. Isolated protoplasts regenerated cell walls, developed into thalli, and propagated in large numbers under aeration in the preparative scale-culture system. Typical bioflavor compounds produced from the regenerated plants, as well as from field-collected plants, were found to be long chain aldehydes, which gave a typical seaweed odor. The long chain aldehydes were formed enzymatically from unsaturated fatty acids and released into the culture fluid. A Percoll/mannitol discontinuous density gradient separation of the heterogeneous protoplasts led to a selection of cell lines with high production of bioflavor. The cells that regenerated from protoplasts were immobilized by polymer matrices such as alginate, -carrageenan, agarose, and agar. Living cells entrapped in alginate beads in aerated cultures survived best. However, the beads started to breakdown after two months. The immobilized cells demonstrated a higher bioflavor production than did the cultured cells.     

Parietochloris incisa comb. nov. (Trebouxiophyceae, Chlorophyta)

A coccoid green alga, Myrmecia incisa Reisigl, was isolated from the soil of Mt Tateyama, Japan. Electronmicroscopy revealed that the organism has pyrenoids sparsely covered with starch segments and traversed by many parallel thylakoid membranes, and zoo-spores with counterclockwise basal body orientation. Due to the presence of these features, we have proposed a reclassification of M. incisa into the genus Parietochloris, Trebouxiophyceae.     

Asexual life history by quadriflagellate swarmers of Ulva spinulosa (Ulvales, Ulvophyceae)

This is the first report of a Ulva species reproducing asexually solely by quadriflagellate swarmers. Ulva spinulosa Okamura et Segawa specimens were collected from Ukibuchi on the Pacific coast of Kochi Prefecture, southern Japan. Quadriflagellate swarmers were released from these specimens. The swarmers showed negative phototaxis before settlement. Thalli cultured from these swarmers also released quadriflagellate swarmers in culture. Microspectrophotometric studies demonstrated equivalent DNA in nuclei of vegetative cells in thalli of U. spinulosa and in sporo‐phytes of the other Ulva species with sexual life history (U. fasciata Delile). Furthermore, the quadriflagellate swarmers of U. spinulosa had the same DNA value, demonstrating that the quadriflagellate swarmers are produced without meiosis.     

Observation on the life cycle of Bulbochaete allahabadensis sp. nov. (Chlorophyta,Oedogoniacea)

Bulbochaete allahabadensis sp. nov. is described from a temporary pond at Allahabad. Most of its life-cycle stages have been observed. It differs from other known species of the genus Bulbochaete in having characteristic oospores and interesting behaviour of androspores. Andropores after liberation from normal vegetative cells may germinate anywhere and form dwarf males or produce several celled branched germlings with precocious formation of antheridia. Such zoospore-like behaviour of androspores confirms the observations made by other workers under culture conditions.     

Parasexual fusion products in green algae: Enteromorpha and Ulvaria (Ulvales,Chlorophyta)

Enteromorpha linza and Ulvaria oxysperma in North Carolina reproduce exclusively by asexual zoospores. Calcofluor white staining indicated that newly released zoospores lack significant cellulose cell wall material, making them suitable for treatment as protoplasts in a parasexual fusion process using high pH-Ca²⁺, PEG and centrifugation. Presumptive fusion products were identified by their larger size, twin chloroplasts and eyespots, and presence of fluorescence labelled and unlabelled portions. Parasexual fusion and karyogamy were confirmed by elevated levels of nuclear DNA in fusion cell germlings. In addition, aceto-orcein staining of fusion cell products revealed a diploid chromosome complement of 2N = 20 in Enteromorpha linza. Fusion cells were isolated by killing the more numerous adjacent unfused zoospores with 2-3 min exposure to blue light (410–490 nm). Unexposed fusion cells could be readily distinguished and recovered by micropipette at the 10-day stage.Center for Marine Science Research UNC-W Contribution No. 008.     

Magnolia denudata var. glabrata var. nov. (Magnoliaceae) from Hunan,China

Magnolia denudata var. glabrata Y. L. Wang et S. Z. Zhang var. nov. is described and illustrated from Hunan, China. The variety occurs mainly in semi‐evergreen forest of south Hunan at altitudes between 700 and 1260 m a.s.l. It differs from M. denudata var. denudata by its green and glabrous twigs and leaves which are glabrous above and have some white pubescence underneath. With its white flowers consisting of mostly 9 tepals, it differs from M. sprengeri Pamp. which mainly has 12 tepals in various shades of red/pink to white. The new variety is rare and considered endangered due to habitat destruction.     

Eugenia terpnophylla var. keralensis var. nov. (Myrtaceae) from Kerala,India

The new variety Eugenia terpnophylla Thw. viz. var. keralensis S. M. Shareef, E. S. Santhosh Kumar et Roy is described and illustrated from Kerala, India. It differs from the typical variety by its narrowly or broadly elliptic leaves with more numerous lateral nerves, sub‐orbicular petals and ellipsoidal fruits.     

Chemical composition and 13C NMR spectroscopic characterisation of ulvans from Ulva (Ulvales, Chlorophyta)

The chemical composition and structures of several ulvan extracts isolated from various Ulva species were studied. They were all composed mainly of rhamnose, glucuronic acid, xylose, glucose and sulphate with smaller amounts of iduronic acid and traces of galactose. Proteins were also present, most likely as contaminants. Precise quantification of the uronic acid content by chemical-enzymatic hydrolysis coupled to HPAEC-PAD analysis and by colorimetry was not achieved, most likely due to the incomplete hydrolysis of glucuronan segments, inadequate HPAEC-pulsed-amperometric response factor for iduronic acid and to a possible differential colorimetric response of the two uronic acids. ¹³C NMR spectroscopic investigation of different ulvans demonstrated that they were all based on ulvanobiuronic acid 3-sulphate A and B repeating units [β-D-Glc pA-(1->4)-α-L-Rhap3S and α-L-IdopA-(1->4)-α-L-Rha p3S, respectively] as well as contiguous β 1->4 linked D-glucuronic acids possibly occurring either in ulvan or as a separate glucuronan. Marked variations in the content of the repeating structures were seen among the different samples. However, due to the limited number of samples studied, no conclusion was reached concerning the effects of species and ecophysiological conditions on the chemistry of ulvan. This revised version was published online in June 2006 with corrections to the Cover Date.     

Tremacron aurantiacum var. weiningense (Gesneriaceae) var. nov. from Guizhou,China

Tremacron aurantiacum var. weiningense (Gesneriaceaea), a new variety of Tremacron aurantiacum found in northwest Guizhou, China, is described and illustrated. This new variety differs from T. aurantiacum K. Y. Pan var. aurantiacum in the following respects: it has appressed pubescence and tomentum on the lower surface of its leaves, inflorescence is 4–8‐flowered, 5–10 cymes, peduncles and pedicels are covered with glandular pubescence, the corolla is thin with tube‐like upper lips indistinct and cut‐like, the stigma is 1, capitate.     

Beardia vancouverensis gen. et sp. nov. (Juglandaceae): permineralized fruits from the Eocene of British Columbia

Large numbers of permineralized juglandaceous fruits were identified in calcareous nodules from the Eocene Appian Way locality on Vancouver Island, British Columbia, Canada. The fruits, small dorsiventrally flattened nutlets, 4.5-7.0 mm long and 5.5-9.0 × 3-5 mm in diameter, were studied using cellulose acetate peels. They are wingless, ribbed, and have a lobed epicarp that surrounds the nutlet. Cells of the inner epicarp are thin-walled and traversed by a system of branching vascular strands. The stony nutlet wall is composed of fibers, with an outer layer of distinctive idioblasts. The fruits have a symmetry like that in Juglandaceae, subfamily Juglandoideae, tribe Platycaryeae, while the fibrous nut walls are like those of subfamily Engelhardioideae. This unique combination of characters indicates that these fruits represent a new genus and species of Juglandaceae: Beardia vancouverensis gen. et sp. nov. The excellent preservation of the Appian Way specimens has allowed a unique view of the internal fruit anatomy and external morphology. As the only wingless, flattened nuts known in the family, they further extend the range of morphological variation in fruits in the family. These fossils further support the hypothesis that North America was an important center of generic diversity for Juglandaceae during the early Tertiary.     

Diluted seawater promoted the green tide of Ulva prolifera (Chlorophyta,Ulvales)

Ulva prolifera (Müller) J. Agardh is the main causative species of the 2008 Yellow Sea green tide incident. We investigated the influences of diluted seawater on the vegetative growth and reproductive cell formation of the alga. The thalli that were cultivated under low salinities (10‰ and 20‰) and low pH values (pH around 7.0) showed obvious and steady biomass gain, while those cultivated under high salinities (40‰) and relatively higher pH conditions (pH around 8.0) manifested significant biomass loss. The trend was, however, completely the opposite for reproductive cell formation and there were indications that enrichment, over very wide concentration ranges of both nitrogen and phosphate, could significantly promote vegetative growth. Results also indicated that relatively low salinity and low pH regimes boosted vegetative growth but were unfavorable for reproductive cell formation and vice versa. Based on these results, the possible origin and development mechanisms of the green tide event are discussed. Eutrophication in the Changjiang River estuary and adjacent sea areas, as well as extremely high freshwater inflows before, and during, the flood of 2007 – due to the full operation of large‐scale water facilities in the area – may have both played an important role in the formation and development of the green tide event.     

Mallomonas corymbosa var. interrupta nov. var. (Synurophyceae) from Argentina

A new variety of Mallomonas corymbosa is described from a pond in Nahuel-Huapi National Park (Argentina): M. corymbosa var. interrupt nov. var. Fine structure of scales and bristles has been studied by scanning and transmission electron microscopy.     

Morphology and life history of Scytosiphon canaliculatus comb. nov. (Scytosiphonales,Phaeophyceae) from Japan*

Morphology of field material and life history in culture were studied in Scytosiphon canaliculatus (Setchell et Gardner) comb. nov. from northern Japan. Erect gametophytes of S. canaliculatus are cylindrical, tubular, up to 7 mm wide and 40 cm long, and without regular constrictions. S. canaliculatus has pronounced anisogamy and ascocysts accompanied with plurilocular gametangia. The life history of S. canaliculatus showed an alternation between erect gametophytes and crustose prostrate sporophytes bearing unilocular sporangia. Since field sporophytes of S. canaliculatus were found to be identical with Hapterophycus canaliculatus Setchell et Gardner (Ralfsiaceae, Phaeophyceae), it is proposed to transfer H. canaliculatus to the genus Scytosiphon. In the field, gametophytes with plurilocular gametangia appeared in spring and disappeared in summer. Sporophytes with unilocular sporangia were collected in late autumn and winter. Unilocular sporangia were produced at 15°C in short-day culture conditions and unispores developed into erect gametophytes at 5–15°C. It is suggested that the seasonal Occurrence of gametophytes in the field is due to the seasonal formation of unilocular sporangia, which is regulated by temperature and photoperiod.     

Paralygodium meckertii sp. nov. (Schizaeaceae) from the Upper Cretaceous (Coniacian) of Vancouver Island, British Columbia, Canada

More than 50 specimens of permineralized fertile pinnules with abaxially borne sporangia have been discovered in calcareous marine nodules from the Upper Cretaceous (Coniacian) Comox Formation from the Eden Main localities on Vancouver Island, British Columbia, Canada. Isolated pinnules 1.6–3.0 mm wide × 1.6–2.8 mm long are lobed and abaxially enrolled to form irregular globose structures. Pyriform sporangia 216–300 μm wide × 360–468 μm long occur in two rows on the abaxial surface of pinnule lobes. Sporangia have an apical annulus of 15–18 cells. Spores are tetrahedral and trilete, 33–42 μm in diameter, with straight to concave interradial sides, laesurae extending nearly to the equator, and a psilate exine. Spores are assignable to the sporae dispersae genus Deltoidospora. Fertile pinnules are compared to fossils of Anemia poolensis and two previously described species of Paralygodium, and show closest similarities to P. vancouverensis from the Eocene of British Columbia. The Cretaceous Eden Main specimens differ in number of pinnule lobes and their morphology and are described as a new taxon: P. meckertii sp. nov. This discovery extends the Cretaceous geographic range of Paralygodium from Japan to North America and adds to our knowledge of the diversity of extinct schizaeaceous ferns.