La presenza di Euphorbia hyberna L. subsp. insularis (Boiss.) Briq. sull'Appennino ligure

Abstract

The presence of Euphorbia hyberna L. subsp. insularis (Boiss.) Briq. in the Ligurian Apennines. — The author studies the geographical distribution and the ecology of Euphorbia hyberna L. subsp. insularis (Boiss.) Briq. in the Ligurian Apennines, where the plant occurs in several stations which are localized in two distinct areas: in the group of Mt. Dente (province of Genoa) and near the Capanne di Marcarolo (province of Alessandria). Euphorbia insularis is recorded only in Liguria, the Apuane Alps (Tuscany), Corsica and Sardinia. The climatic, edaphic, topographic and biotic characteristics of the stations in which the plant is found in Liguria are pointed out. It grows in different environmental conditions, but occurs only in localities with northerly or north easterly exposure, at altitudes between 700 and 950 m; it attains the best development in open places, like grassland and glades, where it grows profusely. On the whole, Euphorbia insularis requires a climate characterized by a strong oceanicity, i.e. by moderate temperatures, a high amount of rainfall, and a notable atmospheric humidity throughout the year. However, the plant shows no particular edaphic requirements, and its occurrence on the serpentine soils is only due to the low competition in the plant-communities of these stations. The author emphasizes the remarkable phytogeographic interest of Euphorbia insularis, which probably represents a tertiary atlantic relict and has survived in the Ligurian Apennines owing to peculiar geo-climatic conditions.     

Struttura e biomassa dei popolamenti fitoplanctonici del Lago Omodeo (Sardegna centrale)

Abstract

Composition and biomass of phytoplanktonic communities of Lago Omodeo (Central Sardinia).—A qualitative and quantitative study has been made on the phytoplankton of Lago Omodeo. The algal associations are typical of eutrophic waters. The dominant blue-green algae in summer and autumn were: Chroococcus dispersus, Microcystis flos-aquae, Aphanizomenon flos-aquae, Anabaena flos-aquae, Anabaena planctonica; dominant in winter and spring the diatom Melosira distans. The mean standing crop of algae for the trophogenic zone was 9.2 mm³/l; a maximum crop of 53 mm³/l was recorded in August during a Microcystis bloom.     

Monte Linas nuovo anello di congiunzione nell'areale della Scilla obtusifolia Poir

Abstract

MONTE LINAS, A NEW BRIGDE STATION IN THE SARDINIAN DISTRIBUTION OF SCILLA OBTUSIFOLIA POIR. — Two new phytocenosis of Scilla obtusifolia Poir. in Sardinia on Monte Linas have been described; their particular interest is that they connect the so far stations of this species in Sardinia. Monte Linas acts as a bridge between the southern sardinian stations and the northern ones, which have been already described by DESOLE (1959).     

Influenza a distanza dei metalli sopra lo sviluppo di organismi vegetali inferiori

Summary

The Author relates about two new spontaneous stations of «Salvia Sclarea» in Sardinia, one of them is probably a shelter-station of another one pre-existing in a lower zone being about 200 meters from it. He refers about the actual area of the species; he describes the two stations and their relative plant-communities pointing out the indexes of plentifulness of the consociated species and comparing the biological spectra of them.

Wishing to research the reason why the species is so restive to spread spontaneously, while it is easily fitted for cultivation, the Author carries on a compared chemical-pedological study of the two stations with three other spontaneous stations near Sassari. He concludes that the «Salvia Sclarea» in sub-alkaline ground does not present particular exigences of chemical constitution, while it would meet difficulties to spread spontaneously in not very soft ground.

As the mentioned difficulties depend from particular conditions of aeration, temperature and humidity of the ground, the Author reserves to himself to make a further research in his next study.     

La vegetazione degli stagni della zona di Olbia (Sardegna nord-orientale)

Abstract

Vegetation of the ponds in the zone of Olbia (northeast Sardinia). – The present paper contains a study on the vegetation of the ponds and marshes in the neighbourhood of Olbia. The following well determined associations have been ascertained: Chaetomorpho-Ruppietum, Salicornietum fruticosae, Arthrocnemeto-Limoniastretum monopetali, Juncetum maritimi, Scirpetum maritimi, Caricetum divisae, Schoeneto-Plantaginetum crassifoliae. Furthermore, some other consociations have been observed (with: Pholiurus incurvas and Triglochin bulbosum; Juncus subulatus; Scirpus setaceus and Spergularia rubra; Agropyrum elongatum and Spartina juncea).

The authors have also taken into consideration the present distribution of the vegetation in relation to the modifications due to the fact that this area has been reclaimed.     

Contributo alla conoscenza sistematica del genere Genista in Sardegna: I. Genista acanthoclada DC.

Abstract

Contribution to the systematic knowledge of the genus Genista in Sardinia: I. Genista acanthoclada DC. – The author takes into consideration the problems concerning some species of the genus Genista in Sardinia. Full details are furthermore given on the ecology, distribution, floristic composition and taxonomic position of Genista acanthoclada ssp. sardoa.     

A Comparative Study on Essential Oil Intraspecific and Seasonal Variations: Melissa romana Mill. and Melissa officinalis L. from Sardinia

Two species of Melissa are currently present in Sardinia: Melissa officinalis L. and Melissa romana Mill . Our research can only count on a few supported evidences (as reported in Flora Italiana and Moris) and some notes on new stations in Sardinia that give us some information about morphology, distribution, bioecological, and ethnobotanical characteristics of both species. In this paper, we present the results of the research about morphological aspects of M. romana vs. M. officinalis, and their essential oils in different stations at different phenological periods. Moreover, we compared the essential oil of M. romana with the one obtained from M. officinalis growing in the few naturalized stations still present in Sardinia. The most evident morphological differences between the two entities are the long‐stalked capitate glandular trichomes, shorts and inclined capitate trichomes, and peltate hairs. The chemical composition of essential oil presents several significant differences between the species. In fact, oils show that in none of the phenological stages, M. romana recalls in its composition M. officinalis. Major distinctions are also evident between dry and fresh plants, and among essential oils distilled in different seasons.     

Osservazioni embriologiche,sistematiche ed ecologiche su Allium parciflorum Viv.

Abstract

Embryological, systematic and ecological observations on Allium parciflorum Viv. The morphological observations and the comparison with some allied species have shown a good taxonomic isolation of Allium parciflorum: this has suggested to ascribe it to a new section.

It has been observed that the female gametophyte develops according to the disporic-type, as in other species of Allium previously studied.

The distributional area in Sardinia has been considerably extended and many ecological data are also given.     

Alcune specie e varietà nuove per la flora della Sardegna

Abstract

New species for Flora of Sardinia. — The Author remarks the presence of new species for Sardinia with some observations on the distribution and habitat.     

La Vegetazione del Comelico (Alto Cadore)

Riassunto

L'Autore studia l'embriologia di due specie che crescono spontaneamente in Sardegna: Arthemisia arborescens L. e Chrysanthemum coronarium L.

Per tutte e due le specie il numero cromosomico aploide è n=9, e lo sviluppo del gametofito maschile e femminile è normale; particolare interesse presenta la costituzione della regione antipodale.     

Rhododendron ferrugineum L. in fitocenosi relitte dell'Appennino settentrionale

Abstract

Relict communities of Rhododendron ferrugineum L. in Northern Apennines. — On the Apennines Rhododendron ferrugineum vegetates spontaneously only on the Tuscan-Emilian part, but particularly on the Northern side, on Cima Belfiore (1810 m), on Mount Prado (2053 m), on Mount Libro Aperto (1937 m). The Rhododendron stations are to be found on the Northern slopes of the Apenninic ridges at an altitude between 1750-1937 meters (Libro Aperto). They have the aspect and sometimes the same floristic composition, of the hypsophyle Vaccinium and Empetrum heaths covering almost alla the summits of the Tuscan and Emilian Apennines. The environmental conditions which have preserved these Apenninic Rhododendron heaths could probably be the abundant snowfalls, (precipitations over 2000 mm per year), the acidity of the soil derived from the Oligocene hard sandstone and finally to a certain degree of continentality.     

A palm fossil closely related to Chamaerops humilis L. from the Lower Miocene of Sardinia

Abstract

This paper deals with the anatomical and histological study of a silicified specimen of a palm consisting of a part of the trunk surrounded by roots. The sample comes from the Lower Miocene of North West Sardinia. The comparison with fossil species and exsting species leads to the conclusion that the specimen belongs to a new fossil species closely related to Chamaerops humilis L., widespread throughout the Mediterranean area. Paleo-environmental considerations confirm the presence in Sardinia, in the epoch in question, of formations of Mediterranean forest corresponding in part to forest existing in North Africa today.     

Buxus Balearica Willd., Elemento Mediterraneo-Occidentale della Sardegna

Summary

The occurance of Buxus balearica Willd. in Sardinia, already reported by Gennari (1864), and its indigenous state are confirmed by the present study. Its station and geographic distribution as well as the biocenosis in which this species takes part (Barbusi near Sulcis in S. Sardinia) are considered.

The study of the Barbusi station, in comparison with others hitherto known, brings a general confirmation to Chiarugi's view concerning the mountainous origin of the mediterranea elements. Besides, it emphasizes the differences between the stations of B. balearica, an element of the mediterranea “macchia”, and those of B. sempervirens, an undergrowth element of mesophilous formations (deciduous woods), which only rarely belonges to more termophilous bioceneses.

The author notes that both species belong to the same stage of Q. Ilex and that the altitude range in which the Q. Ilex stage is comprised is very wide in the different mediterranean regions. In addition, the author emphasizes that Buxus sempervirens occurs in Corsica and Atlas up to the upper limit of Quercetum Ilicis, together with species belonging to higher stages, whilst Buxus balearica belongs to the lower limit of Quercetum Ilicis in the underzone “Olea-Ceratonia”. The altimetric separation of these species is, therefore, obvious.

Due to the compenetration of floras of mountainous origin during the phases of the Ice-period, the knowledge of the segregation epoch of these species from each other is made impossible.

Buxus balearica occupies actually as eocene substratum and, therefore, shows edaphic exigences for soils of a certain age: a condition not occurring for Buxus sempervirens.

Both Buxus species, together with other horeal-tertiary ones (all constituting actually, in the mediterranea countries, a special relict flora) belong to the Lauretum, in a historic sense (Chiarugi).     

The flora of the island Piana (Sardinia,Italy)

Abstract

The author reports the results of the herborizations carried out on the island Piana (northeastern Sardinia) located between Cape Ceraso and Cape Coda Cavallo. The flora consists of 250 entities distributed in 154 genera, inclusive of 54 families. The author gives information regarding the mail features of the vegetal coverage, and points out the presence of two species: Limonistrum monopetalum (L.) Boiss. and Omithoga-lum arabicum L., which are extremely rare in the little islands.     

Althenia filiformis Petit: contributo alla conoscenza della ecologia della germinazione

Abstract

New data on the ecology of germination of Althenia filiformis Petit. – The author investigated the natural environment where this species, halophyte and hydrophyte, germinates. The relationships between temperature, salt concentration of pools in which Althenia filiformis lives, and the dormancy of seeds were examined. In particular the author studied the behaviour of this species considering the natural conditions of pools of Orbetello (Tuscany) and Simbirizzi (Sardinia).     

Habitat distribution and predation on a western population of terrestrial Leiopelma (Anura: Leiopelmatidae) in the northern King Country,New Zealand

Abstract

A new population of terrestrial Leiopel‐matid frog was discovered in the Whareorino Forest, northern King Country, New Zealand, in 1991. Searches were carried out from June 1991 to December 1993 to determine the species present and to document variation in external morphology, habitat, and local distribution. These confirmed that a terrestrial frog resembling L. archeyi is present in the area, as well as Hochstetter's frog Leiopelma hochstetteri and the introduced Australian hylid frog Litoria aurea.

In Whareorino Forest, the terrestrial Leiopelma was mostly above 500 m altitude and L. hochstetteri above 350 m. The terrestrial Leiopelma occupies sites under rocks and logs in forest. It also occurs in vegetation, such as crown fern Blechnum discolor, tree fern Cyathea smithii, hook grass Uncinia uncinata, and rice grass Microlaena avenacea. Egg clusters of this frog were found in crown fern and tree fern, as well as under stones.

The terrestrial Leiopelma is susceptible to predation by Litoria aurea and rats. This is the first documented evidence of predation on Leiopelma on the New Zealand mainland. The future of this small remnant Leiopelma population is uncertain, and further investigation of the impact of anuran and mammalian predators is needed.     

Primo contributo alla micoecologia della lettiera di lentisco in alcune isole minori della Sardegna meridionale

Abstract

Preliminary account of the microfungi colonizing Pistaca lentiscus L. litter - A preliminary account of the microfungi colonizing Pistacia lentiscus L. leaf litter in five small islands of South Sardinia is carried out. Two species, Beltrania rhombica Penzig and Endophragmiella boewei (Crane) Hughes are present in almost all the samples investigated. A very low index in richness of species seems to be characteristic of this particular area.