THE TYPE SPECIES OF CERAMIUM (RHODOPHYTA), CERAMIUM VIRGATUM ROTH: TYPIFICATION AND PHYLOGENY

The type species of Ceramium is Ceramium virgatum Roth (1797, Cat. Bot I: 148, pl. VIII, fig. 1). This has been treated as a probable synonym of Ceramium nodulosum (Lightfoot) Ducluzeau, one of the species formerly confused under the illegitimate name Ceramium rubrum (Hudson) C. Agardh. However, in 1996 Silva showed that C. nodulosum (Lightfoot) Ducluzeau is a later homonym of C. nodulosum de Candolle 1805, and advocated conserving C. rubrum with a neotype. As an alternative to this, we investigated whether the name C. virgatum might be available for this species. The lectotype of C. virgatum is Roth's illustration of a much-branched, fully corticate, Ceramium specimen from Eckwarden, North Sea, which could represent any member of the ' C. rubrum' group. We obtained material resembling Roth's, from the North Sea island of Helgoland, as a potential epitype. Its rbc L sequence was aligned with sequences of all C. rubrum -like species in the British Isles, i.e. C. secundatum , C. botryocarpum , C. pallidum and ' C. nodulosum '. The Helgoland material was clearly conspecific with ' C. nodulosum ' from Ireland (0.08% divergence). We therefore suggest that the name C. virgatum Roth should be employed for this species. Phylogenetic analyses of these sequences aligned with various representatives of the tribe Ceramieae, placed the North Atlantic C. rubrum -like species in two well-supported clades. In one of these, C. virgatum is basal to C. secundatum and C. botryocarpum. The other clade consists of C. pallidum and a partly ecorticate species resembling C. diaphanum.     

Ceramium gobii n. sp. (Rhodophyta, Ceramiales), a brackish-water red alga in the Baltic Sea

A geographical survey was made of the distribution of diaphanoid Ceramia in the Baltic Sea and adjacent waters west of the Baltic. It was found that Ceramium plants with so-called 'Gobi's' parasporangia (monosporangia) have a wide distribution in the Baltic Sea at salinities of ca (3) 5–8%. This brackish-water Ceramium is here described as a new species, Ceramium gobii. At higher salinities in the south of the Baltic Sea and on the Swedish west coast, round parasporangia (polysporangia) indicate the occurrence of other Ceramium species. The new species is very similar to the brackish-water species Ceramium radiculosum , which was described from river-mouths to the Gulf of Trieste (Italy). A comparison was made of several diaphanoid Ceramium species, C. diaphanum, C. tenuicorne, C. gobii , and C. radiculosum , including (1) size of male plants, (2) type of paraspores, (3) vegetative characters.     

25 Proposal of a new red algal genus in the ceramieae (ceramiaceae, ceramiales)

A new genus is proposed to accommodate four species belonging in the Ceramium flaccidum complex based on comparative vegetative morphology and rbc L sequence analysis: C. flaccidum (Harvey ex Kuetzing) Ardissone (1871), C. gracillimum, C. Agardh (1824), C. fimbriatum S. & G. (1924) and C. rectocorticum Dawson 1950. Comparative rbcL sequence analysis indicates that this complex forms a distinct monophyletic clade separate from other Ceramium species. Although C. flaccidum has been placed in Hormoseras Kuetzing 1841 (as H. flaccidum Harvey ex Kuetzing 1862), the type species of Hormoceras is Ceramium diaphanum . The new genus is characterized by alternate branching, incomplete cortication, production of three cortical filament initials of which the basipetal initial divides horizontally, and unicellular rhizoids terminating in pad-like structures produced from periaxial cells. Cortical filament development is discussed for related genera in the tribe Ceramieae ( Campylaephora, Carpoblepharis, Centroceras, Ceramium, Corallophila, Herpochondria, Microcladia, Reinboldiella ). Rbc L-based phylogenies indicate that the new genus is sister to Centroceras , a genus possessing three cortical filament initials. The phylogenetic relationships within the tribe may correlate with cortication patterns that characterize each genus     

偏序钝叶草（Stenotaphrum secundatum）与地毯草（Axonopuscompressus）营养器官特点的研究

偏序钝叶草（Ｓｔｅｎｏｔａｐｈｒｕｍｓｅｃｕｎｄａｔｕｍ（Ｗａｌｔ．）Ｋｕｎｔｚｅ）与地毯草（Ａｘｏｎｏｐｕｓｃｏｍｐｒｅｓｓｕｓ（Ｓｗａｒｔｚ）Ｂｅａｕｖ．）均为热带和亚热带的草坪优良草种,它们的匍匐枝节节可生根和产生分蘖,覆盖面积大。偏序钝叶草根毛分布范围较广,寿命较长;地毯草植株平铺地面,它们都是良好的保土植物。偏序钝叶草茎和叶的维管束都较密集,厚壁组织较发达,植株有一定的韧度。它们的叶的维管束解剖呈现“花环”结构,属Ｃ４植物。     

遮光处理对三种钝叶草的生长习性与光合特性的影响

钝叶草属(StenotaphrumTrin.)的3个种,普通钝叶草(Stenotaphrum helferi)、森特钝叶草(Stenotaphrum secundatum)和金边钝叶草(Stenotaphrum secundatumcv.varietgatum)均为耐荫性草种。光合测定结果显示,3种钝叶草的光合作用在中午均未出现光抑制,其净光合速率日变化呈现“单峰”曲线型;除金边钝叶草外,森特钝叶草与普通钝叶草在75%遮光下的净光合速率要高于全光照下的。野外观测发现,金边钝叶草与森特钝叶草一直维持在营养生长阶段,而普通钝叶草的生长发育周期最短,在大约3个月就完成了从营养生长到生殖生长的全过程,包括抽穗、开花和结实。光照下森特钝叶草生长最好,而在遮光下普通钝叶草长势最好。在75%的遮光条件下,3种植物都保持了较好的生长状况,并且保持终年常绿的景观效果。总的来说,3种钝叶草都表现出了耐荫能力,而普通钝叶草的耐荫性最强,在遮光条件下生长迅速,叶片呈现翠绿色,因而是一种非常理想的阴生草坪草种;金边钝叶草是生长最为缓慢的品种,但它的叶片黄绿相间,能给人焕然一新的视觉感受。     

CENTROCERAS INTERNITENS N. SP. (RHODOPHYCEAE,CERAMIACEAE) FROM THE WESTERN TROPICAL NORTH ATLANTIC OCEAN1

Centroceras internitens n. sp. (Rhodophyceae, Ceramiaceae) was found in the Florida Keys and Bermuda only as an epiphyte on Ceramium nitens (C. Agardh) J. Agardh. It is described on the basis of many collections, including an abundance of reproductive material representing all stages of the life history. Laboratory culture has not been successful. The type locality is a well-known limestone platform on the Atlantic Ocean side of West Summerland Key, Florida Keys. In addition to living material, C. internitens was found on eight herbarium specimens of Ceramium nitens at the United States National Museum, thereby establishing records of its occurrence throughout the Caribbean Sea and dating back to 1887.     

LIFE HISTORY STUDIES OF SELECTED BRITISH CERAMIUM SPECIES1

Ceramium shuttleworthianum, C. rubrum, and C. pedicellatum demonstrated a Polysiphonia type of life history without deviations in unialgal culture. The reported absence of fertile gametophytic plants of C. shuttleworthianum and C. flabelligerum from northern Scotland in the northern part of their geographical ranges is probably attributable to the inhibition of gametangial production by the environment.     

NEW INSIGHTS IN THE TAXONOMY OF THE CERAMIUM SINICOLA COMPLEX: RESURRECTION OF CERAMIUM INTERRUPTUM (CERAMIACEAE,RHODOPHYTA)1

Phylogenetic relationships of the Ceramium sinicola complex (C. interruptum and C. sinicola) including C. codicola were studied using nucleotide sequences of rbcL and small subunit rDNA, and the RUBISCO spacer was used for sequence comparison of each species. A reassessment of the taxonomic rank and the evolutionary trend within the complex was inferred from a comparative morphological study and molecular data sets based on 11 samples from eight populations from the Pacific coast of the United States and Mexico. Intraspecific relationships were poorly resolved, but the resurrection of C. interruptum as a distinct species was strongly supported by both morphological and molecular data. Ceramium interruptum is distinguished by the combination of the following features: thalli uncorticated at the first internode above the dichotomy, presence of four corticating filaments, 7–11 segments between branching points, rhizoids digitate, and epiphytic on a variety of hosts. Our molecular analyses show that C. sinicola is the sister group to C. codicola, and C. interruptum is basal to them. These phylogenetic relationships allowed for an assessment of the trend in the evolution of cortication pattern and attachment mode to the host.     

CERAMIUM INKYUII SP. NOV. (CERAMIACEAE,RHODOPHYTA) FROM KOREA: A NEW SPECIES BASED ON MORPHOLOGICAL AND MOLECULAR EVIDENCE1

Ceramium inkyuii sp. nov. is newly described based on samples collected from the east coast of Korea and compared with similar species such as C. paniculatum and C. tenerrimum. The new species is characterized by pseudo‐dichotomously branched thalli with a twist in the upper part, a single row of spines on the abaxial side, strongly inrolled apices, and the presence of gland cells. In contrast, C. paniculatum has alternate branches and lacks gland cells, and C. tenerrimum is spineless and also lacks gland cells. Ceramium inkyuii was observed to be an annual species producing tetrasporangia in the spring to summer and cystocarps in the fall. Plastid‐encoded rbcL and nuclear small subunit (SSU) rDNA sequences were determined in four samples of C. inkyuii from different locations and six samples of four putative relatives. All four C. inkyuii replicates from three different locations had identical sequences of each gene, and the interspecific sequence divergences were enough to warrant its natural entity. The phylogenies of the rbcL and SSU rDNA sequences also indicate the monophyly of C. inkyuii. The spinous C. inkyuii was more closely related to the spineless C. tenerrimum than to the spinous C. paniculatum.     

MOLECULAR SYSTEMATICS OF CERAMIUM AND CENTROCERAS (CERAMIACEAE,RHODOPHYTA) FROM BRAZIL1

Morphological investigations identified 11 Ceramium Roth species, of the 18 previously reported from Brazil. Phylogenetic analyses of sequences of the chloroplast‐encoded rbcL gene confirmed the presence of seven of these species. Three other species are reported from Brazil for the first time. Ceramium affine Setchell & Gardner and C. filicula Harvey ex Womersley were previously known only from the Pacific Ocean (Mexico and Australia, respectively). A new species, C. fujianum Barros‐Barreto et Maggs sp. nov., is described here. Its general habit is similar to that of C. strictum sensu Harvey from Europe but it has one less periaxial cell than C. strictum; its cortical filament arrangement is closest to C. deslongchampsii Chauvin ex Duby, also from Europe, but whorled tetrasporangia partially covered by cortical cells differ strikingly from the naked protruding tetrasporangia of C. deslongchampsii. Ceramium species in which each periaxial cell cuts off transversely only a single basipetal cell formed a robust clade. The genus Ceramium as represented in Brazil is not monophyletic with respect to Centroceras Kützing and Corallophila Weber‐van Bosse; Ceramium nitens, which has axial cells completely covered by rounded cortical cells formed by acropetal and basipetal filaments, did not group with any Ceramium clade but was weakly allied to a species of Corallophila. All three Brazilian Centroceras sequences were attributed to a single species, C. clavulatum.     

Some new species and new combinations of marine red algae from the central Pacific

Six new species in five genera of Rhodophyta are described. A new combination for Polyopes hakalauensis is also proposed. These taxa were encountered while preparing a manual of marine red algae of the Hawaiian Islands. Among the Halymeniales, two blade-like species of Halymenia, H. cromwellii sp. nov. and H. stipi-tata sp. nov., are distinguished from other species by habit and anatomical differences, including the possession of a stipe by the second. Halymenia hakalauensis Tilden 1902 is transferred to Polyopes as P. hakalauensis (Tilden) Abbott, replacing P. hawaiiensis Kajimura which is considered a synonym. A new species of Prionitis, P. corymbifera sp. nov., shows a corymbose branching pattern different from the mostly pinnate to subdichotomous branching of Japanese and Californian species. In the Gigartinales, Chondracanthus okamurae Abbott is named for a specimen which Okamura included in his understanding of Gigartina (now Chondracanthus tenellus), but which has terete axes, differing from C. tenellus (Harvey) Hommersand which is com-planate throughout. Chondracanthus intermedius (Sur-ingar) Hommersand is placed in synonymy with C. tenellus. The occurrence of C. tenellus in Hawai'i is a new distribution record from Asia. Three new species are added to the Ceramiales, Ceramium tranquillum Meneses (Ceramiaceae), Dasya kristeniae sp. nov. and Dasya murrayana Abbott & Millar (Dasyaceae). Distinctive features of Ceramium tranquillum are internodes that are three to five times longer than the height of nodes, and nodes that never project beyond the diameter of the internodes, giving straight margins except when fertile. Dasya kristeniae is a diminutive epiphyte which is nearly ecorticate, with tetrasporangial stichidia that are rectangular having apices that are curved or nodding, and cystocarps that have flaring ostioles above a constricted pericarp. Dasya murrayana was earlier misidentified with Dasya iyengarii Børgesen, and re-examination of those plants show continuous cortication throughout, where cortication is almost completely lacking in D. iyengarii except near the base. Dasya murrayana has a tufted habit, with indeterminate branches about the same sizes as the main axes, the plants growing on rock, whereas plants of D. iyengarii are not tufted, with indeterminate branches attenuate, and an epiphytic habit.     

Bicarbonate Transport and Alkalization of the Medium by Four Species of Rhodophyta

Photosynthesis by four species of Rhodophyta: Ceramium rubrum,Ceramium tenuissimum, Gelidium crinale and Pterocladia capillaceawas optimal at 25 to 30?C and at pH 8.0 to 8.5. The measuredrates of photosynthesis exceeded the rate which could be supportedby the carbon dioxide arising from the dehydration of bicarbonatein the medium, from 2.7- to 10.9-fold at pH 8.0 and from 9-to 33.4-fold at pH 9.0, in the absence of measurable extracellularcarbonic anhydrase activity. Assays for malic enzyme and pyruvate,orthophosphate dikinase were negative, indicating that bicarbonateions are taken up by a transport system rather than by an accessorycarbon fixation pathway. When the algae were allowed to photosynthesizein an unbuffered system a DCMU (3-[3', 4'-dichlorophenyl]-1,1-dimethylurea)-sensitive alkalization of the medium was observed.This alkalization was shown to have a 1:1 stoichiometry withphotosynthetic carbon fixation. Alkalization of the medium occurredfrom 3.4 to 5.8 times the theoretical rate of supply of hydroxylions arising from the dehydration of bicarbonate. The data areconsistent with the operation of a bicarbonate transport systemin these macroalgae, in which electrical neutrality and pH balanceare maintained by hydroxyl ion efflux. A difference observedbetween the time-course of alkalization and oxygen evolutionsuggests that the transport of the two ions is not compulsorilycoupled. Key words: Bicarbonate transport, alkalization of the medium, Rhodophyta     

Ceramium cimbrium (Rhodophyceae, Ceramiales) from Scandinavia; structure, reproduction and systematics

Ceramium cimbricum, originally described from Limfjorden, Denmark was isolated into unialgal culture form several localities in southern Norway. The distinguishing features include straight, often unequal apices, 4–5 periaxial cells and narrow cortical bands. Reproductive structures are described for the first time in European material and a Polysiphonia-type of life history was demonstrated, though irregularities were also seen. Culture observations of phenotypic variability and examination of type material suggest that C. cimbricum and the widely recorded C. fastigiatum may be conspecific. However, the latter binomial is illegitimate.     

Auxinvorkommen und Auxinstoffwechsel bei mehrzelligen Ostseealgen

Summary The algae Enteromorpha prolifera, Enteromorpha compressa, Cladophora sericea, Pylaiella litoralis, Ceramium rubrum, Nemalion multifidum and Furcellaria fastigiata contain extractable auxin. After paper chromatography in different solvents, the Triticum section-test and Avena curvature-test showed that the main activity was due to IAA. This result was supported by colour tests with indole reagents after paper and thin layer chromatography.In Ceramium rubrum, Enteromorpha prolifera and Enteromorpha compressa the low IAA level was correlated with a high content of inhibitors.Only Furcellaria fastigiata contained an auxin in the nonacidic fraction. As yet an identification was unsuccessful.Alkali-hydrolysis of the algae using N NaOH liberated large amounts of auxins. Also in this case, IAA was the main auxin. With thin layer chromatography 2 or 3 other indole derivatives could be detected.

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Aus einer Dissertation der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Rostock (Schiewer, 1965).     

Morphological and random amplified polymorphic DNA features in populations ofCeramium kondoi (Rhodophyta)

Morphological and RAPD features ofCeramium kondoi populations were investigated and compared in different locations in Korea. The plant length and branching pattern were more variable in Jindo population than others. RAPD data showed thatC. kondoi plants were divided into two clades; the southern group including Jindo and Bangpo population, and the northern group including Yonpyongdo and Oeyondo population. Morphological features inC. kondoi populations corresponded with RAPD data, which differed from those ofC. boydenii from the same location. These results suggest that RAPD might be useful for elucidating genetic variation among the wild populations ofC. kondoi.     

Temperature requirements for growth and survival of macroalgae from Disko Island (Greenland)

The temperature requirements for growth and upper temperature tolerance were determined in 16 macroalgal species collected on Disko Island (Greenland). The upper survival temperatures were examined in 1°C steps, and growth measured at 5°C intervals between 0 and 20°C using a refined method, where the fresh weight was determined weekly or fortnightly over a period of 5 or 6 weeks. To express temperature-growth responses, growth rates of temperature-acclimated plants were taken. Two groups with different temperature requirements were identified: (1) A stenothermal group includingAcrosiphonia arcta, Acrosiphonia sonderi, Urospora penicilliformis, Devaleraea ramentacea, Desmarestia aculeata, Pilayella littoralis, growing between 0 and (10 to) 15 (or 20)°C with optima between 0 and 10°C. The upper survival temperatures in these species and inChromastrum secundatum, Chromastrum virgatulum, Chordaria flagelliformis were between 17 and 23°C (duration of experiment: 2 weeks). (2) A eurythermal group includingEnteromorpha clathrata, Enteromorpha intestinalis andPolysiphonia urceolata growing between 0 and 20°C with growth optima at 10 or 15°C. The upper survival temperatures in these species and inChaetomorpha tortuosa, Bangia atropurpurea andEudesme virescens were between 24 and 31°C. These algal species showed little adaptation to the Arctic temperatures. In contrast, algae from the first group exhibited a relatively high adaptation to low temperatures — approaching the low temperature requirements of Antarctic algae. The results are discussed in relation to the geographic distribution of individual species.     

Flora Algale Dell'Isola Lachea (Golfo di Catania)

Abstract

Observations on the seaweeds on the Island of Lachea. — Within the frame of the research on seaweeds in the Eastern part of Sicily which is being carried out at the Botanical Department of Catania University, the AA. have undertaken a study on the seaweeds to be found on the Island of Lachea. The material has been collected from the supralittoral to the infralittoral. One hundred and thirty-five species have been identified and data about the local distribution and habitat have been given. The following species are new to Sicily: Spatoglossum solierii (Chauv.) Kuetz., Bonnemaisonia asparagoides (Woodw.) Ag., Gelidiella ramellosa (Kuetz.) Feld. et Ham., Antithamnion cruciatum (C. Ag.) Naeg. var. profundum G. Feld., Antithamnion plumula var. bebbii (Reinsch) J. Feld., Ceramium bertholdi Funk, Ceramium codii (Richards) G. Maz., Spermothamnion repens (Dillw.) K. Ros. var. flagelliferum (De Not.) Feld., Griffithsia barbata (Smith) C. Ag., Polysiphonia biformis Zan., Lophocladia lallemandi (Mont.) Schmitz; and the following species are new to Eastern Sicily: Codium difforme Kuetz., Bryopsis penicillata Kuetz., Liebmannia leveillei J. Ag., Thuretella schousboei (Thur.) Schmitz, Dudresnaya verticillata Le Jol., Amphiroa cryptharthrodia Zan., Corallina squamata Ell. et Sol., Pseudolithophyllum expansum (Phil.) Lem., Ceramium rubrum var. implexo-contortum Solier, Ptilothamnion pluma (Dillw.) Thuret, Aglaothamnion neglectum G. Feld.