Osservazioni sugli stadi iniziali della morfogenesi in coltura di alcune specie del genere Peyssonnelia Decaisne

Abstract

Researches on the morphogenesis of the genus Peyssonnelia Decaisne. — This paper reports the first result on morphogenetic researches in cultures of 3 species of the genus Peyssonnelia Decne. The development of Peyssonnelia rubra (Grev.) J. Ag. is of «Dumontia type »(CHEMIN, 1937) that one of Peyssonnelia squamaria (Gmelin) Decne. and of Peyssonnelia inamoena Pilger of «Naccaria type». According to our cultures results the morphogenesis of genus Peyssonnelia is of two type. Sample of P. squamaria and P. inamoena are collected in the gulf of Trieste (Nord Adriatic Sea) those of P. cfr. rubra in the Morlaix Bay (English Channel). Taxonomic value of the results are discussed.     

VEGETATIVE AND REPRODUCTIVE MORPHOLOGY IN RETICULOCAULIS GEN. NOV. AND NACCARIA HAWAIIANA SP. NOV. (RHODOPHYTA,NACCARIACEAE)1

A secondarily formed reticulum of cells that encloses axial strands and a carposporophyte that is almost entirely converted to sporangia are the diagnostic features of a new genus, Reticulocaulis (Naccariaceae, Nemaliales), with R. mucosissimus as the type species. A new species of Naccaria, N. hawaiiana permits close comparison with the new genus and other previously described species of Naccaria. Until now, no Naccariaceae were known in the Pacific, and these new taxa are part of the sketchily known subtidal marine flora of Hawaii.     

A taxonomic appraisal of Callophyllis and Euthora (Rhodophyta)

Critical examination of the literature and specimens of the three described species of Euthora indicates that the acceptance of the northern species E. cristata (C. Ag.) J. Ag. and E. fruticulosa (Rupr.) J. Ag. has been based on lack of familiarity with the degree of variation normal within one species, and these two species should be united. The carpogonial branch system of this combined species is typical of that found in the genus Callophyllis within which it should therefore be included as Callophyllis cristata (C. Ag.) Kütz. The taxonomic position of the only other species of Euthora, E. tristanensis Baardseth, cannot be determined until information on the carpogonial structure is available.     

In situ spore germination in Erythrotrichia carnea

The in situ germination of monospores is reported in European and North American material of Erythrotrichia carnea (Dillw.) J.Ag., and its significance discussed in relation to branching in the genus.     

A species of Cryptonemia new to Europe

The morphology, reproduction and seasonal variation of a large foliose species of Cryptonemia collected in the drift in 1971–73 at Cork Harbour, Republic of Ireland, is described and compared with the known species of the genus. Although obviously closely related to a group of foliose Pacific species: C. borealis Kylin, C. obovata J. Ag. and C. angustata (Setch. et Gardn.) Dawson, the Irish Cryptonemia is not completely identifiable with any one of these and is therefore described as C. hibernica sp. nov., pending a revision of the genus.     

NORTH CAROLINA MARINE ALGAE. IX. ONSLOWIA ENDOPHYTICA GEN. ET SP. NOV. (PHAEOPHYTA,SPHACELARIALES) AND NOTES ON OTHER NEW RECORDS FOR NORTH CAROLINA1

Four benthic algae are reported here for the first time in the North Carolina flora. The new brown algal genus and species, Onslowia endophytica Searles, is described as an endophyte of Halymenia floridana from the North Carolina continental shelf. New records of Boodleopsis pusilla and Naccaria corymbosa from North Carolina constitute range extensions of these tropical species on the American coast north from Florida. Blastophysa rhizopus, an endophyte and epiphyte known from the North Atlantic coast of Europe and America as well as the Caribbean is reported from North Carolina for the first time and in a new host, Predaea feldmannii.     

Temperature responses of macroalgae from the tropical island Hainan (P.R. China)

The temperature tolerances of 24 tropical macroalgae collected on Hainan Island (P.R. China) were investigated. For some isolates, growth response curves were also determined. The upper survival temperatures (USTs, 32–37°C) of these tropical west Pacific strains are similiar to those of tropical Atlantic species. With regard to their lower survival temperatures (LSTs) the species investigated show high variations: 12 species have LSTs between 16 and 7°C (Hypnea musciformis (Wulfen) Lamx. var esperi J, Ag., Centroceras clavulatum (C. Ag) Mont., Falkenbergia hillebrandii (Bornet) Falkenberg, Gelidiopsis intricata (Ag.) Vickers, Halymenia maculata J. Ag., Hypnea cenomyce J. Ag., Hypnea spinella (C. Ag.) Kütz., Gracilaria changii (Xia et Abott) Abott, Chang et Xia, Dictyopteris repens (Okam.) Boerg., Laurencia cartilaginea Yamada, Gelidium pusillum (Stackh.) Le Jol., Laurencia sp.). Their LSTs and temperature requirements for growth (range: 15–30 °C, optimum: 25–30 °C) are mostly similar to those of tropical west Atlantic and amphi-Atlantic (sub)tropical macroalgae as well as to tropical isolates of species with an Atlantic tropical to warm-temperate distribution. The remaining 12 species have LSTs between 6 and 1 °C (Ulva conglobata Kjellm., Ulva fasciata Delile, Padina boryana Thivy, Dictyosphaeria cavernosa (Forssk.) Boerg., Boodlea composita (Harv.) Brand, Boergesenia forbesii (Harv.) Feldm., Cladophora vagabunda (L.) van den Hoek, Enteromorpha compressa (L,) Grev., Enteromorpha intestinalis (L.) Link, Gracilaria tenuistipitata Chang et Xia, var liui Chang et Xia, Monostroma nitidum Wittr. and Valonia aegagropila C. Ag.). Their LSTs are mostly similar to those of Atlantic macroalgae with a tropical to (warm-) temperate distribution. The results are discussed with respect to the factors which may have triggered the development of the temperature requirements of the various species.     

STRUCTURE,LIFE HISTORY AND SYSTEMATICS OF RHOICOSPHENIA (BACILLARIOPHYTA). IV. CORRELATION OF SIZE REDUCTION WITH CHANGES IN VALVE MORPHOLOGY OF RH. GENUFLEXA1

Rhoicosphenia Grun. is a relatively isolated genus among the biraphid diatoms. Morphological changes in an isopolar member of the genus, Rh. genuflexa (Kütz.) Medlin, were investigated using light and scanning electron microscopy. The fully raphid valve showed changes in its flexure that could be correlated with size reduction during its life history from the initial cells to the smallest cells found in the population. Bands showed changes in number (from three to one) related to size reduction. Rh. genuflexa is morphologically similar to Rh. abbreviata (C. Ag.) Lange-Bert. (=Rh. curvata (Kütz.) Grun.), although the two are distinct taxa. These observations support previous contentions that Rhoicosphenia is a natural taxonomic grouping.     

THE MORPHOLOGY AND DEVELOPMENT OF SOME PROMINENTLY STALKED SOUTHERN AUSTRALIAN HALYMENIACEAE (CRYPTONEMIALES,RHODOPHYTA). II. THE SPONGE-ASSOCIATED GENERA THAMNOCLONIUM KUETZING AND CODIOPHYLLUM GRAY1

Three members of the red algal family Halymeniaceae (Thamnoclonium dichotomum (J. Ag.) J. Ag., Codiophyllum flabelliforme (Sond.) Schmitz, and C. decipiens (J. Ag.) Schmitz) are investigated. All are endemic to southern and southwestern Australia, possess basal stalks of substantial size and firmness, and are consistently associated with specific sponge taxa. In each case, the sponges are bonded by collagen-like fibrils to the host cuticle without modifying the algal tissue at the ultrastructural level. Secondary cortication and prominent growth rings occur in the stalks of all three species, and in each the pit plugs between cells become wider, more convoluted and less electron dense with increasing distance from the surface. Such pit plugs are apparently a unique attribute of the stalked Halymeniaceae. The three species share pit plug, sponge association and stalk morphological features but are not otherwise closely related, as they actually represent three distinct genera.     

Striking autapomorphic evolution in Physotheca J.J.Engel & Gradst. (Marchantiophyta: Lophocoleaceae) blurred its actual relationships with Leptoscyphus Mitt.

Abstract

The taxonomic status and phylogenetic position of the monotypic liverwort genus Physotheca J.J.Engel & Gradst., including P. autoica J.J.Engel & Gradst. endemic to Ecuador, are inferred from phylogenetic analyses of two cpDNA loci. The results indicate that the genus is nested within Leptoscyphus and the new combination, L. autoicus (J.J.Engel & Gradst.) Vanderp. & Gradst., is made. This indicates, along with an increasing body of evidence, that extreme morphological transformations can obscure the phylogenetic signal present in morphological data.     

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.     

THE GENUS HYPOGLOSSUM KÜTZING (DELESSERIACEAE,RHODOPHYTA) IN THE TROPICAL WESTERN ATLANTIC,INCLUDING H. ANOMALUM SP. NOV.1

Observations are made on the occurrence and distribution of the red algal genus Hypoglossum Kützing (Delesseriaceae, Ceramiales) in the tropical western Atlantic. In addition to the type of the genus, H. hypoglossoides (Stackh.) Coll. & Herv., three other species are reported: H. anomalum sp. nov., H. involvens (Harv.) J. Ag., and H. tenuifolium (Harv.) J. Ag. A key is presented to distinguish these four species. The newly described species, H. anomalum, is like other species in the genus in that its branches arise endogenously from the primary axial row but it is unique in that the branches emerge from the parent blade at some point between the midline and the margin of the blade. The new species is reported from Puerto Rico and Florida.     

Calospatha subsumed in Calamus (Arecaceae: Calamoideae)

Summary  Based on previously published phylogenetic research, the genus Calospatha Becc. (Calamoideae) is placed in synonymy within Calamus L. The new combination, Calamus calospathus (Ridl.) W. J. Baker & J. Dransf. is made.     

Acrochaetium botryocarpum (Harv.) J. Ag. (Rhodophyta) in Southern Australia

The morphology, ecology, cytology and systematics of Acrochaetium botryocarpum (Harv.) J. Ag. have been studied. This species occurs throughout the year in southern Australia and grows on a variety of hosts. The variable appearance of the prostrate system results from the effect of the substratum upon its morphology. Plants reach a height of 6 mm; cells of the erect filaments contain a single chromoplast with a variable number of pyrenoids. Tetrasporangial plants occur mainly in winter and sexual plants occur mainly in spring and early summer; the two generations are isomorphic. Stages of fertilisation have been observed and photographed. Acrochaetium polyrhizum (Harv.) J. Ag. is referred to the synonomy of A. botryocarpum, and A. codicolum Brg., A. grande (Levr.) De Toni fil. and A. rhizoideum (Drew) Sm. are regarded as probable synonyms. This study of A. botryocarpum indicates that host specificity, substrate relations, form of spermatangia and immediate post-fertilisation activity may not be as reliable as formerly thought for making taxonomic distinctions within the Acrochaetium-Rhodochorton complex.     

SEASONAL GROWTH,BIOMASS, AND REPRODUCTIVE BEHAVIOR OF THREE SPECIES OF RED ALGAE IN GODAVARI ESTUARY,INDIA1

Growth and different phases in the life histories of Bos-trychia tenella (Vohl.) J. Ag., Caloglossa leprieurii (Mont.) J. Ag., and Catenella impudica (Mont.) J. Ag. were estimated for 23 months from January 1986 to December 1987 in the Gautami Godavari estuary of lndia. Seasonal data on hydrographical conditions, biomass, and plant length were collected from three stations in this estuary. Biomass was minimum in August and September and maximum in January and February, as was frond length of tetrasporic and vegetative plants. Temperatures of 24°–27°C and salinities of 5–20 ppt coincided with optimal growth for all three algae. In all three species, tetrasporophytes were present in all months of the year without any seasonal periodicity, and nearly 50% of the plants were tetrasporophytes. The gametophytes of B. tenella and C. leprieurii and cystocarpic plants of C. impudica occurred from October to May, with greatest abundance in January. The abundance of spermatangial and cystocarpic plants in the populations of B. tenella and C. leprieurii ranged from 3 to 15%. Spermatangial plants of Catenella impudica could not be identified, and the abundance of cystocarpic plants was very low.     

Brominated sesquiterpene metabolites of Hypnea pannosa (Gigartinales,Rhodophyta)

A chloroform extract of freeze-dried Hypnea pannosa J. Ag., collected from the intertidal region near Karachi, Pakistan, furnished three bromine-containing secondary metabolites. These were characterised, using spectroscopic techniques, as 10-bromo-7, 12-dihydroxy-Δ^{3, 4}-laurene, filiformin and filiforminol. This is the first report of halogenated terpenoids from the genus Hypnea. author for correspondence     

STUDIES OF PACIFIC ISLAND PLANTS. XXVI. METROSIDEROS COLLINA (MYRTACEAE) AND ITS RELATIVES IN THE SOUTHERN PACIFIC

The genus Metrosideros (Myrtaceae) is an abundant and taxonomically confusing component of the vegetation throughout much of its range. In the southern Pacific, from the New Hebrides eastward to the Society and Tuamotu Islands, the genus is represented by one variable species, M. collina (J. R. & G. Forst.) A. Gray, in which three widespread varieties seem to merit recognition. An attempt is here made to clarify the nomenclature and inter-relationships of these varieties. Additionally, two local endemics are related to the M. collina group—M. gregoryi Christophersen in Samoa and M. ochrantha A. C. Sm. (sp. nov.) in Fiji.     

The genus Saitobryum (Pottiaceae) revisited

The genus Saitobryum R.H.Zander comprises two species: S. lorentzii (Müll.Hal.) Ochyra distributed in Mexico and the Central Andes and Saitobryum pascoense M.J.Cano & J.A.Jiménez from the Central Andes of Peru, described here as new. The new species is distinguished from S. lorentzii by its upper and middle laminal cells papillose throughout, border of 2–3 rows of thick-walled and smooth cells, lamina usually with bistratose patches, and occasionally bistratose margins. The diagnostic characters of Saitobryum are re-evaluated and a key to the species of this genus is provided. Both species are described and illustrated. New localities for S. lorentzii and a map showing the complete distribution of this genus are given.     

Genetic analysis based on plastidial and ribosomal sequences of the endemic bi-edaphic taxon Jurinea pinnata (Lag.) DC. (Compositae) in the Guadix-Baza Basin

Jurinea pinnata (Lag.) DC. is one of the three species of the genus that grows in the Iberian Peninsula. This species grows on gypsum and dolomite, substrates rich in endemic taxa. Actually, the genus Jurinea Cass. is particularly rich in endemic taxa associated with special substrates. The island-like distribution of J. pinnata makes it an interesting case for the study of genetic differentiation processes. The geographical proximity of J. pinnata and J. humilis makes this evolutionary puzzle even more difficult to solve. These facts could affect the genetic attributes of the species as far as diversity and differentiation are concerned. Our field research involved the sampling of individuals from eight populations of J. pinnata. Of them, six were located in the Guadix-Baza Basin. We used sequences of ribosomal and plastid DNA to perform the genetic analyses. Results revealed no differences between individuals occurring on the two kinds of substrates and evidences of hybridization between J. pinnata and J. humilis. Furthermore, the phylogenetic analysis revealed a possible polyphyletic origin for the adaptation to special substrates within the Jurinea genus, while monophyly was observed in species from the Iberian Peninsula. This could indicate a more general adaptation to arid or saline environments.     

Observations of spore morphology of some Pottiaceae Schimp. species (Bryophyta) in Turkey

The spores of Syntrichia ruralis (Hedw.) F. Weber and D. Mohr., S. princeps (De Not.) Mitt., S. subulata (Hedw.) F.Weber and D.Mohr var. subulata, S. subulata (Hedw.) F.Weber and D.Mohr var. angustata (Schimp.) J.J. Amann and S. subulata (Hedw.) F.Weber and D.Mohr var. graeffii Warnst. were studied by light and scanning electron microscopy for the first time. The apertural region consists of a leptoma in all spores. All taxa of the family are uniform in their spore morphology. The spores of the five taxa are of granuloid type. The spore wall of the Pottiaceae family includes sclerine (the distinction between exine and perine may be difficult to define) and intine. The taxonomy of the genus Syntrichia is discussed on the basis of its spore morphology.