Table of Contents

This is an account of investigations carried out on denatiaceous hyphomycetes colonizing the litter of different seven areas of mediterranean maquis. Hundred and eight species were observed, determined and a drawing for each, obtained from photographic pictures, to point out the most important morphological characters, was prepared keeping as fundamental the dimensions of the different structures. Some considerations on the role of the different species into the ecosystem are carried out.

The taxa of Orobanche occurring in Sicily and on the surrounding islets have been surveyed in the field and in herbaria. In total, 23 species occur in the region. O. litorea is found to be distinct from O. minor and O. thapsoides from O. canescens. O. crenata and O. ramosa are serious pests that cause heavy losses to broad bean and tomato cultures, respectively-

Pyrenula relicta Etayo & Puntillo, a lichen species new to science, is currently known from only two localities, in Southern Italy and Western France, where it grows in shaded and sheltered canyons with very interesting lichen floras.

Spanish Sierra Nevada has one of the richest and most original flora of the western Mediterranean region with a large number of endemic species. The area is considered one of the biodiversity "hotspots" of the Mediterranean Basin. Its high summits are particularly important from a conservation point of view and its flora is extremely vulnerable to the impacts of climate change. This paper shows a detailed analysis of the flora in the upper vegetation belt (cryoromediterranean zone) of Sierra Nevada, based on an updated delimitation of its area (38.76 km2). In total, 185 species belonging to 44 families and 116 genera were catalogued. The most relevant families were; Poaceae (24 taxa), Asteraceae (20) and Caryophyllaceae (16). Despite its small territory, the high vegetation belt is prominent in endemic taxa (37.3%), 55 of which do not exceed the range of Sierra Nevada. The number of threatened taxa is 39 and the biological spectrum shows the dominance of hemicryptophytes (63.16%) and chamaephytes (26.31%). We believe that this high mountain flora data could be a strong indicator of the long-term climatic variations and might therefore be used in the future to observe possible upward movements of the taxa.

An updated geographical distribution of the genus Gagea Salisb. in Sardinia with a grid map for each taxon is given. This study is based on literature, herbarium and field investigations. The examined species are G. bohemica (Zauschn.) Schult. & Schult. f., G. dubia A. Terracc., G. foliosa (C. Presl) Schult. & Schult. f., G. fragifera (Vill.) E. Bayer & G. López González, G. granatellii (Parl.) Parl., G. lojaconoi Peruzzi and G. soleirolii F. W. Schultz. The occurrence in Sardinia of the phytogeographically interesting G. fragifera is here confirmed in a single locality. Single new localities are reported for G. dubia and G. granatellii. Finally, an analytical key for the identification of the studied species is presented.

Species new to Tunisia observed on small islands of the northern coast (the Galite and Zembra archipelagos, islets of Bizerte). During botanical surveys conducted as part of the "Mediterranean Small Islands Initiative" the authors report nine new taxa for the flora of Tunisia, on the basis of unpublished observations and / or recent taxonomic revisions. Four other rare species of particular interest are also reported. All of these findings are discussed in terms of biogeographical relationships among islands and between islands and mainlands, particularly in this complex area of the central Mediterranean Sea. The authors conclude that exploration efforts need to continue on these difficult to access islands with a flora that still has many unresolved taxonomic problems.

According to our research, the presence of Pinus nigra on Mt. Ainos of the island of Cephalonia, Greece is restricted to just five individuals within the Abies cephalonica forest at an altitude of 1200 m. The issues of its indigenous presence, as well as its conservation status are being discussed

Phyllanthus tenellus Roxb. (Phyllanthaceae), native to Madagascar and Mauritius’s Island, was found naturalized around Messina (E Sicily). This report represents the first record for Italy and the Mediterranean area.

The authors report the recent discovery in Tunisia of a new chlorophyll spermaphytes within the Asteraceae family. The fields dodder or the devil's hair (Tanacetum parthenium (L.) Sch. Bip.) native to North America was observed, for the first time, in the north-west of Tunisia (in the Kroumiria).

Second contribution to the distribution of microspecies belonging to the Portulaca oleracea aggregate (Portulacaceae) in the Euro+Med Plantbase territories.On the whole 35 new distributional data referred to 8 microspecies are given

Fifty-nine species of lichens and lichenicolous fungi are reported from Calabria. Sixteen species are new to Italy and forty-four are new to Calabria. So, calabrian Lichen flora encrease to ca. 1.000 species.

A new subspecies of the dwarf perennial herb Bolanthus creutzburgii Greuter (Caryophyllaceae) is described from the coast of SW Kriti (Crete), Greece: B. creutzburgii subsp. zaffranii Phitos, Turland & Bergmeier. In morphology, flowering period, ecology, and geographic distribution it is compared with B. creutzburgii subsp. creutzburgii, which is endemic to the high mountains of W and C Kriti. The conservation status of the new subspecies is evaluated as Endangered (EN) according to IUCN criteria.

Twelve species of Dematiaceous Hyphomycetes found on litter of Quercus suber are described. A new combination Repetophragma lignicola from Endophragmiella lignicola is proposed.

This is the twenty first of a series of reports of chromosome numbers from Mediterranean area, peri-Alpine communities and the Atlantic Islands, in English or French language. It comprises contributions on 16 taxa: Alyssum from Iran, by S. Bolourian, A. Tavassoli & M. Pakravan (Nos 1737-1743); Genista from Italy, Sardinia and Corse by T. Cusma Velari, L. Feoli Chiapella & G. Bacchetta (Nos 1744-1748); Genista from Greece, Cyprus and Israel, by T. Cusma Velari & L. Feoli Chiapella (Nos 1749-1750); Isoëtes from Sicily, by A. Troia, P. Marino & A. M. Orlando (No 1751), Pilosella from Italy, by E. Di Gristina, A. Geraci & P. Marino (No 1752).