Search results for "Cistus"
showing 9 items of 19 documents
MARIOLA: a model for calculating the response of mediterranean bush ecosystem to climatic variations
1995
Abstract The paper summarizes the bush ecosystem model developed for assessing the effects of climatic change on the behaviour of mediterranean bushes assuming that temperature, humidity and rain-fall are the basic dimensions of the niche occupied by shrub species. In this context, changes in the monthly weather pattern serve only to outline the growth conditions due to the nonlinearity of response of shrubs to climatic factors. The plant-soil-atmosphere system is described by means of ordinary non-linear differential equations for the state variables: green biomass, woody biomass, the residues of green and woody biomasses, faecal detritus of mammals on the soil, and the total organic matte…
Nuclear DNA content variation inHalimiumandXolantha(Cistaceae)
2008
Abstract Chromosome numbers and nuclear DNA contents were determined in several taxa of two genera of Cistaceae, Halimium and Xolantha. The diploid chromosome number 2n = 18 is stable within the genus Halimium. In Xolantha, the diploid chromosome number 2n = 14 was confirmed in X. tuberaria, and hexaploid (2n = 36) and octoploid (2n = 48) cytotypes were found in X. guttata. DNA amounts, first reported here for these genera, were determined by flow cytometry of propidium iodide-stained nuclei. Within Halimium there is a more than twofold difference in genome size between H. calycinum (7.61 pg DNA) and H. atriplicifolium (3.66 pg DNA). Within the genus Xolantha, absolute genome sizes of 7.3 a…
Chemical composition and herbicidal activity of the essential oil from a Cistus ladanifer population from Spain
2012
[EN] The essential oil composition of Cistus ladanifer grown in central Spain was analysed by gas chromatography and gas chromatography/mass spectrometry, revealing it to be rich in oxygenated compounds, with trans-pinocarveol (20.00%), bornyl acetate (7.03%) and terpinen-4-ol (6.37%) as the main monoterpene compounds. Viridiflorol (13.59%) and ledol (4.36%) were the main constituents of the oxygenated sesquiterpene fraction. Large amounts of-pinene (4.70%) were found in the hydrocarbonated fractions. To study its possible use as a natural herbicide, the oil was tested invitro against Amaranthus hybridus, Portulaca oleracea, Chenopodium album, Conyza canadensis and Parietaria judaica, compl…
Biometrical and ecological observations on Cistus salvifolius L.
1993
Abstract Biometrical observations on Cistus salvifolius L. (Cistaceae), a species with a very variable morphology, are presented: data, collected in Sicily, are relative to three environments in which populations of Cistus salvifolius live: garigue, maquis, pinewood. Measurements are compared with other ones, found in the literature, and in some cases they disagree or supply useful indications. On the basis of the different light regimes in the three environments, and of the parameters in which the difference among the three populations is most evident, some observations about the reaction to shade in Cistus salvifolius were made. On the basis of the few data collected, the intraspecific di…
Antioxidant activity and chemical composition of three Tunisian Cistus: Cistus monspeliensis Cistus villosus and Cistus libanotis
2015
The chemical composition of three rockrose Cistus species, Cistus monspeliensis, Cistus libanotis and Cistus villosus, collected in Tunisia, was studied by HPTLC, focusing on the terpenes and phenols constituents. Diterpenes of Cistus are important as the main constituents of the leaf sticky aromatic resin, known as labdanum, which are highly appreciated in perfumery. Polyphenols in the methanolic extracts of each species were identified, quantified as total and as flavonoids and tannins, and tested for antioxidant activity. Diterpenes were evident in C. libanotis and C. monspeliensis, whereas they were practically absent in C. villosus; C. libanotis had higher phenolic amount, whereas anti…
Lectotypification of the names of two species of Fumana ( Cistaceae )
2004
The names Cistus ericoides Cav. and C. laevis Cav. are typified. These names apply to two species, currently classified within the genus Fumana (Dunal) Spach, but the names have been frequently misapplied and both of thempose typification problems. The type specimen of the first has not been found. Thus an illustration is chosen as type and an epitype designated. The original material of C. laevis comprises a mixture of two different species. One element is selected to clarify the application of this binomial.
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…
Lectotypification of the name Cistus stipulatus, basyonim of Helianthemum stipulatum (Cistaceae)
2015
The typification of the name Cistus stipulatus Forsskål (≡ Helianthemum stipulatum (Forsskål) Christensen) is discussed. The designation of the nomenclatural type is based on an assessment of Forsskål’s original material. The name is lectotypified selecting a specimen from the Herbarium Forsskålii in the National Herbarium Copenhagen at C.
Novedades sobre taxonomía y nomenclatura de híbridos vasculares españoles
1990
The nomenclature of some Iberian hybrids is revised and several new combinations are proposed: <i>Centaurea X subdecurrens</i> var. segobricensis, C.</i> X <i>subdecurrens</i> notbosubsp. <i>albuferae, Cistus</i> X <i>hybridus</i> nothosubsp. <i>grandiflorus</i> var. <i>secallianus. C.</i> X <i>ledon</i> var. <i>recognitus, C. </i>X <i>nigricans</i> var. <i>longifolius, C.</i> X <i>nigricans</i> nothosubsp. <i>grosii</i> and <i>Onopordum</i> X <i>humile</i> var. <i>turolensis</i>. Besides, a new nothosubspec…