No abstract

The essential oils of leaves (from male and female plants), unripe fruits and leaf-buds of different samples of Pistacia atlantica collected from Greek East Aegean islands (Kalimnos and Lesvos) were analysed by GC-MS and GC. Qualitative and quantitative differences among the samples and different organs of the plant were observed. The oils were rich in monoterpenes. The main components in the leaf oil from the female plants were myrcene (17.8%, 24.8%) and terpinen-4-ol (11.6%, 6.0%) in the Kalimnos and Lesvos samples, respectively, while in the leaf oil from the male plants terpinen-4-ol (17.3% Kalimnos) and p-mentha-1(7),8-diene (41.1%, Lesvos) were the dominant constituents. The major components in unripe fruits were terpinen-4-ol (25.7%, 8.9%), myrcene (20.2%, 34.5%) and sabinene (14.9%, 19.5%). In the leaf-buds oils sabinene (52.1%) and α α α α α-pinene (11.6%) were the main constituents in the Kalimnos sample, while in the Lesvos sample the major constituent was p-mentha-1(7),8-diene (42.4%).

The allelopathic influence of four plant tissues of Conyza albida (stems, leaves and inflorescences) on oat growth were investigated using in vivo tests. Oat growth (fresh and dry weights of above and underground parts) was inhibited from phytotoxic activity of upper leaves and inflorescence tissues of C. albida in pot studies. The inhibition was significantly higher than in the other tissues studied. The inhibiting action of crude extracts and volatile compounds from young plants (rosette) and mature plants were examined using two bioassay methods: (a) seed germination and radicle growth of oat and (b) fresh weight of duckweed plants. Both bioassayed species exhibited greater phytotoxic response from the young plants, collected in winter, than from the mature ones.

No abstract

No abstract

Floristic and phytogeographical information is presented in the first of three papers on the flora of Lesvos (East Aegean, Greece). The taxa included here are dicotyledons and belong to families in alphabetical order from Aceraceae to Guttiferae. Of the 92 taxa (79 species, 12 subspecies and one variety) presented, two are new for Greece, five are new for the Aegean islands as a whole, four are new for the East Aegean Islands and 13 are new for Lesvos. New distribution localities on the island are also given for some interesting taxa. Furthermore, the presence of 13 taxa, reported by previous authors without specific collection data, is confirmed. Critical comments are made on 22 taxa whose presence needs confirmation or is considered doubtful or wrong. Chorological, ecological and taxonomic comments are made for the more interesting cases and distribution maps for certain taxa in Greece or Lesvos are given. Finally, the threats and conservation status of some rare and interesting taxa are briefly discussed.

No abstract

Lake Pamvotis is one of the Balkan "ancient" lakes, a Quaternary refugium of great environmental importance and ecological value, that is under various anthropogenic pressures. It belongs to a Natura 2000 Special Area for Conservation and Special Protection Area. Almost in the middle of the lake, there is an inhabited island - one of the two lake islands in Greece – that also attracts touristic interest. Τhe main objectives of the present study are to provide a floristic inventory of the protected island, combining data of two different sampling periods, within a 25 year interval, in order to estimate temporal beta diversity and species turnover of the island’s plant diversity. The value of the absolute and relative turnover rates of the floristic diversity of the island studied are 4.24 and 1.72, respectively and are amongst the higher rates reported for plants. The absolute difference between extinct (E) and immigrant (l) taxa is to a great extent accounted, concerning life forms, by therophytes (1.86), hemicryptophytes (1.56) and geophytes (1.04) and, for habitats, by taxa preferring agricultural and ruderal forms (2.52).