Lucia Viegi

Inventory of the non‐native flora of Italy

Abstract In this paper we present a comprehensive inventory of the non‐native vascular flora of Italy, which was produced within the project “A survey of the Italian non‐native flora”, funded by the Italian Ministry for the Environment. Previously published floristic accounts were the main source of information. Historical records were critically revised and integrated with recent literature, data from herbaria and some unpublished information, so as to obtain a complete, up‐to‐date catalogue of the non‐native vascular plant species that occur spontaneously in Italy. The inventory lists 1023 non‐native species and subspecies, which account for 13.4% of all the Italian flora. The Italian non‐native flora was divided, according to its residence time, into 103 archaeophytes and 920 neophytes. According to its current invasion status, it was classified into 437 casual (42.7% of all non‐native) and 524 established taxa, the latter being divided into 361 naturalized non‐invasive (35.3%) and 163 invasive taxa (15.9%). The inventory includes a group of 62 species (6.1%) that lack recent records (i.e. since 1950). By combining local expertise into a unified, nationwide scheme using a standardized method and terminology, the inventory provides the essential scientific basis for the development of plant invasion research and management in the country.

Non‐native flora of Italy: Species distribution and threats

Abstract In this paper, we provide an overview of the distribution and invasive status of non‐native species in the Italian flora across its administrative regions, biogeographic regions and main land use types, and a synthesis of current knowledge on the threats they pose within the country. The information on non‐native plant species collected during the project “A survey of the non‐native Italian flora” was used to compile comprehensive regional and national databases. The number of non‐native species within a given administrative region increases in proportion to its size, resident population density and latitude, reaching the highest values in the intensively cultivated, heavily industrialized and urbanized Po Plain in northern Italy. The number of casual species is positively correlated with the number of yearly visitors in each region and negatively correlated with the proportion of mountainous terrain within the region. If compared with the Continental and Mediterranean biogeographic regions, the Alpine region yields the lowest number of non‐native species and lowest proportion of casual species. The number and density of introduced species is highest in artificial land use types, particularly in urban areas. A negative impact is reported to be exerted by 203 species, most of which are agricultural weeds.

Flora esotica d'Italia

LUCIA VIEGI, GIOVANNA CELA RENZONI, FABIO GARBARI Istituto Botanico de1l’Universita - Pisa Flora esotica d’Italia *) E’ noto Che la flora di un determinato territorio e il risultato di un cornplesso insierne di fenomeni, alcuni dei quali antichi, va- lutabili con la scala degli eventi geologici, altri pifi recenti 0 attuali, riferibili alla storia del1’uorno e direttamente analizzabili. E’ anche evidente Che la flora di una regione non e statica: costituisce una struttura dinamica, variabile nello spazio e nel tempo, espressione sintetica di modificazioni ambientali esogene (geoclirna- tiche, antropiche) o biologiche endogene (genetiche) a carico dei suoi elementi costitutivi. Dal punto di vista corologico, gli elementi che costituiscono una flora possono essere distinti in « geografici » e ll genetici ». I primi —— elernenti geografici — sono definiti prati- camente dal loro areale, cioe dalla superficie sulla quale una entita tassonornicamente Valutahile e distribuita naturalmente. Nell’arnhito di una flora presente su un deterrninato territorio sono rilevabili, Con le entita Che risultano insediate stahilmente e ll naturalmente » —— considerate « native » 0 ll autoctone » —, pian- te Che si qualificano estranee a quel territorio, sia sotto il profilo epiontologico che geografico, provenienti da diverse e talora lontane regioni della terra. Sono queste le cosiddette « esotiche gg, entita Che sono arrivate in Vario Inodo, per cause naturali o antropiche, pifi o meno recenternente, a far parte della flora di un territorio che non e compreso nell’area naturale della loro distribuzione. L’introduzione di una specie vegetale in un paese diverso da quello in cui e naturalmente distribuita 0 di cui si ritiene originaria (*) Lavoro realizzato con un contributo del C.N.R.

Total Polysaccharide Content of Developing Pollen in Two Angiosperm Species

Abstract The PAS reaction was used to stain total insoluble polysaccharides in whole pollen grains of anthers of Borago officinalis and Lycopersicum peruvianum from early microspore to ripe pollen stage. Total polysaccharide content was quantified with a microdensitometer: in Borago officinalis values showed two peaks, one during the microspore and the other during the binucleate stage; in Lycopersicum, there was a single peak during the latter stage. In both species total polysaccharide content decreased markedly in the last stage of pollen development before anthesis, when starch was hydrolysed and the polysaccharide reserves of the pollen transferred to the cytoplasm. Pollen grain volume was also determined at the various stages. It was found to increase, though with a different pattern in the two species, and to decrease before dehiscence. The results are discussed in terms of cytoembryological data of pollen grain development.

Effects of acidity on the insoluble polysaccharide content of germinating pollen of Pinus pinea L. and Pinus pinaster Aiton

Abstract The PAS reaction was used to stain total insoluble polysaccharides in pollen of two species of Pinus collected in two different years and germinated in vitro at different pH values. PAS-detectable polysaccharides are localized in the intine, cytoplasm and amyloplasts; PAS-undetectable (callose) in the middle of the intine, but only in the distal part of the grain. The total PAS stained polysaccharide content was quantified with a microdensitometer. Values are correlated with germination percentages and pollen tube length. The total polysaccharide content, as well as pollen tube length, varies in each species according to the year, probably due to environmental conditions. Also the various pHs deeply influence pollen germination and tube length, the lowest pH being the most unfavourable condition. At this pH (3.5) the total polysaccharide content is higher than in the control (pH 5.5): this is probably due to a lack of callose synthesis for tube wall or to a depolymerization of this polysaccharide...

Il sospensore embrionale nelle Cruciferae. I. Morfologia e struttura

Abstract Embryo suspensor in Cruciferae. I. Morphology and structure. — Embryo suspensors in seven species of Cruciferae (Alyssum argenteum All., Brassica nigra (L.) Koch, Capsella bursa-pastoris (L.) Medicus, Diplotaxis erucoides (L.) DC., Eruca sativa Miller, Lepidium graminifolium L., Matthiola tricuspidata (L.) R. Br.) were morphologically investigated. These species have significant differences in their seeds, so that probable differences could be found in the structure of their ovules and therefore of their suspensors. Results indicate that it is impossible to generalize on the suspensor morphology and structure even in the same family. In Eruca sativa and Brassica nigra polyploidy and polyteny were found, suggesting a probably important metabolic function of their suspensors. In the other species polyteny was not present; a various degree of polyploidy could probably be assumed, suggesting a less active function of suspensors, maybe absorption and transport of nutritive material from the integument...

Volatile Constituents of Centaurea paniculata Subsp. carueliana and C. rupestris s.l. (Asteraceae) From Mt. Ferrato (Tuscany, Italy)

Abstract The essential oil composition of two endemic species of Centaurea, C. paniculata subsp. carueliana and C. rupestris (Asteraceae) collected on serpentine rocks on Mt. Ferrato (Tuscany, Italy) were investigated by GC and GC/MS. Several classes of compounds were detected, of which sesquiterpenes, (representing the 25.6% of the total oil from C. paniculata and 74.5% from C. rupestris), alcohols (27.8% in C. paniculata and 4.3% in C. rupestris) and aldehydes (12.0% C. paniculata and 2.0% in C. rupestris) were the most abundant, followed by acids, monoterpenes, esters, ketones, hydrocarbons, diterpenes and miscellaneous. A series of unidentifed compounds were also detected. Differences in qualitative and quantitative composition were evidenced and discussed.

The achene pappi and elaisomes of Centaurea L.: Dispersal and germination in some Italian species

The presence/absence of pappi and elaiosomes, types of elaiosome reserves, and germination were studied in 38 Italian taxa belonging to different sections of the genus Centaurea L. Achenes with pappus, with elaiosome, with pappus and elaiosome, and without pappus and elaiosome were found. Many species had elaiosomes containing lipids, which were sometimes associated with proteins and/or starch; in sporadic cases, only proteins were found. Subspecies of the same genus and specimens of the same species from different localities were sometimes diversified with regard to pappus and elaiosome. Germination experiments were carried out in 16 taxa using intact achenes and achenes with elaiosomes removed. In eight taxa, no statistically significant difference was found between germination of achenes with and without elaiosomes. Seeds of C. aeolica, C. aplolepa subsp. ligustica, C. leucophaea, and C. veneris without elaiosome germinated, sometimes in a low percentage, but better than seeds with elaiosome intact.

Effects of Different pH Values on Seed Growth in Pinus Pinaster and P. Pinea

All over the world the studies on negative effects of acid depositions on plants, either wet (acid rain) or dry (largely gaseous), have become increasingly numerous (4,5, 7,10). In particular, damage from NOx and SO2 on forests in extended zones of North America and North-Central Europe are nowadays well known. Acid precipitation may affect the productivity of crop and forest plants by direct or indirect means (necrosis, or soil nutrients effects). Most low pH values in rainwater occur in the spring and summer, so acidity of rainfall is highest when most plants are actively growing (5).

Effects of Different PH on in Vitro Germination of Pinus pinaster Aiton and P. pinea L. Pollen Grains

The effects of different pH values (6.17, 5.50, 4.54, 3.57 in deionized water and 6.36, 5.43, 4.51 and 3.58 in deionized water plus 9% sucrose) on in vitro germination and pollen tube growth in pollen of Pinus pinaster Aiton and P. pinea L. from S. Rossore (Pisa, Italy) were investigated. Standard conditions were the same as in previous in vitro experiments (CELA RENZONI et al., 1983, 1986).