Search results for "Botany"
showing 10 items of 4586 documents
Types of names of Orobanche taxa described from North Africa
2013
In the framework of the revision of the genus Orobanche (including Phelipaea) in the Mediterranean area, the original material for 31 names of new taxa described from North Africa by Ball, Battandier, Forsska°l, Maire (partly with Emberger and Jahandiez), Persoon, Poiret and Pomel has been analysed. Typification is discussed, and where necessary types are designated. Accepted names and synonyms of the recognized taxa are given. Three species are illustrated, and one new combination (O. inexspectata) is proposed.
Isoëtes todaroana (Isoëtaceae, Lycopodiophyta), a New Species from Sicily (Italy)
2009
Isoetes todaroana, a new species from western Sicily (Italy), is described. Morpholog- ical, anatomical and ecological characters are given. The main differential characters are the presence of only two leaf air chambers, rather than four as in all other known species of the genus, and the shape of the scales, which have two lateral rounded lobes and one central spine-like lobe, together with its peculiar calcophilic habitat. So far, the species is known from a single locality.
A new synonym and a new combination in Stipa aliena Keng (Poaceae: Stipa sect. Regelia)
2015
Stipa section Regelia comprises three species occurring in mountainous areas of Central Asia. One of them, S. smithii , was described by Martinovský in 1970, but the taxon has been overlooked in later taxonomical studies. The species was described with two varieties, var. smithii and var. macrocarpa . As a result of our taxonomical studies, we find the typical variety of the taxon to be conspecific with Stipa aliena , and propose that the second one be recognized as Stipa aliena var. macrocarpa comb. nov. Remarks on species belonging to section Regelia and micromorphological patterns of their lemma morphologies are discussed. A key to species close to S. aliena is provided.
Fern-dominated Rock Plant Communities of Tajikistan (Middle Asia)
2015
The results of phytosociological research conducted on the fern vegetation of rock crevices and clefts of the Pamir-Alai Mountains in Tajikistan are presented. During field surveys done in 2010–2013, 78 phytosociological relevés were sampled. Plant species were recorded according to the Braun-Blanquet cover-abundance scale. A synopsis of the fern communities of the montane and high altitude zones in Tajikistan is proposed. In the examined vegetation plots, species of 9 ferns, 58 angiosperms and 13 mosses were recorded. The most frequent ferns were: Cystopteris fragilis, Cheilanthes persica, Asplenium ruta-muraria, Asplenium ceterach, Adiantum capillus-veneris and Cryptogramma stelleri. Six …
Sex ratio and spatial distribution of male and female Antennaria dioica (Asteraceae) plants
2011
Sex ratio, sex spatial distribution and sexual dimorphism in reproduction and arbuscular mycorrhizal colonisation were investigated in the dioecious clonal plant Antennaria dioica (Asteraceae). Plants were monitored for five consecutive years in six study plots in Oulanka, northern Finland. Sex ratio, spatial distribution of sexes, flowering frequency, number of floral shoots and the number and weight of inflorescences were recorded. In addition, intensity of mycorrhizal fungi in the roots was assessed. Both sexes flowered each year with a similar frequency, but the overall genet sex ratio was strongly female-biased. The bivariate Ripley’s analysis of the sex distribution showed that within…
Breeding system and conservation strategy of the extremely endangered Cistus carthaginensis Pau (Cistaceae) of Spain
2001
Cistus carthaginensis is one of the most endangered plants in Europe: at present there exist only a few individuals in Murcia and one in Valencia (SE and E Spain). To design an adequate conservation strategy able to avoid the extinction of this species, various aspects of its reproductive biology were studied. The extreme rarity of C. carthaginensis is not related to problems of development and/or fertility of pollen or ovules produced by the few existing specimens. Meiosis in the pollen mother cells is always regular and chromosome segregation is completely equilibrated in the male gametes. Pollen and ovule production is high and similar to that reported for other related species of Cistus…
Accumulation of Pb and Zn in Bidens triplinervia and Senecio sp. spontaneous species from mine spoils in Peru and their potential use in phytoremedia…
2012
Abstract Heavy metal toxicity has become a global concern due to the ever-increasing contamination of soil, water and crops. Until recent decades little has been known about the remediation of mining sites using spontaneous plants in Latin America. Soil and plant samples were taken in Peru, at a polymetallic mine (mainly silver, lead and copper) in Cajamarca Province, Hualgayoc district. Top soils (0–20 cm) were analyzed for physical and chemical properties by standard methods. Total Pb and Zn concentrations in top soils were determined by ICP-OES. Similar metals in plants were analyzed separately (aerial and root system). Ti content was used as an indicator for contamination of plant sampl…
The floral nectaries in theLimnanthaceae
1992
Floral nectaries in theLimnanthaceae are established as exoscopic basal bulges of the episepalous stamens. Their nectariferous tissues include the epidermis and hypodermal parenchyma and inLimnanthes are vascularized by phloematic branches of the staminal bundles. Secretion occurs mainly through anomocytic stomata but, in addition, probably through the outer cuticularized thin walls of the epidermal cells. The flower structure is comparatively simple. The nectar is often slightly concealed. A wide range of pollinators can be expected, but bees are observed to be the dominant ones. The systematic position of the family is still obscure. Taxonomic placement near to any other geranialian famil…
Diterpenes from Euphorbia segetalis
1998
Numerous new diterpenes including several with new skeletons have been obtained from Euphorbia segetalis.
First report of Phytophthora citrophthora causing fruit brown rot of Feijoa in Italy
2019
Feijoa (Feijoa sellowiana) is native to South America. In the early 20th Century it was introduced into Sicily (southern Italy), where it is grown as an ornamental plant and for its fruits. In 1985 a Phytophthora brown rot of feijoa fruits was reported in the province of Syracuse (eastern Sicily) (2). Several species of Phytophthora, including P. citricola, P. citrophthora, and P. nicotianae, were recovered from soil samples taken from trees with infected fruits. These species were experimentally inoculated on detached feijoa fruits and all incited symptoms of brown rot. However, only P. citricola was isolated from naturally infected fruits. In early autumn 1999, an outbreak of Phytophthor…