The geographical extent of exotic plant species is a major component of invasiveness, which has been explained by intrinsic attributes of the plants, such as growth rate, reproductive type, life form, and biogeographical origin. We assessed quantitatively life cycle and biogeographical origin as determinants of the geographical distribution of naturalized plants in continental Chile, using minimum residence time (MRT) as an estimator of introduction date. We assembled a database with information on 428 plants (principally herbs) in continental Chile, corresponding to 61% of the exotic naturalized flora. For each species we recorded: (1) minimum residence time (introduction date or first recorded date in the country); (2) biogeographical origin (American, Eurasian, others); (3) life cycle (annual, perennial, others); (4) number of Chilean regions occupied by the plant. We found that 82 species (19%) have been recorded in only one region of Chile, while only three species have been found in all 13 regions of the country. About 89% of the species (381) have been found only in central Chile (Regions IV to VIII), while the remaining 11% (47) are found only in the northern (Regions I to III) or southern parts of the country (Regions IX to XII). We detected significant differences in regional spread of naturalized plants according to minimum residence time: those species with shorter MRT had more limited spread ranges than those with longer MRT. Biogeographical origin and life cycle did not explain geographical extent in Chile. This study shows that historical factors are more important than biological ones in determining the geographical extent of naturalized plants in continental Chile. Thus, caution should be exercised when assigning value to biological attributes that may confer invasiveness to naturalized plants.

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Muñoz 2000) constituye una especie nueva para la ciencia. Esta última, junto a Eulychnia aricensis Ritter, Pyrrhocactus saxifragus Ritter y Nolana intonsa Johnst., son endémicas locales. Del total de especies, un 43 % son endémicas y un 52,8 % son nativas no endémicas, existiendo un bajo porcentaje (4,2 %) de especies adventicias; 34 especies (47,2 %) comparten su área de distribución con el Perú. Las familias Asteraceae, Nolanaceae y Solanaceae son las mejor representadas en el área con más de siete especies cada una. Las condiciones climáticas derivadas del evento El Niño 1997-1998 han favorecido el desarrollo de la vegetación en los oasis de neblina al sur de Iquique. Aunque no hay un aumento de las precipitaciones durante el período 1997-1998, sí se aprecia un incremento en las temperaturas así como en el contenido líquido de la neblina, lo que favorecería el desarrollo de una vegetación más exuberante y la expansión del área de ocupación de algunos elementos florísticos]]>

This paper provides a synopsis of the Chilean Asteraceae genera according to the most recent classification. Asteraceae is the richest family within the native Chilean flora, with a total of 121 genera and c. 863 species, currently classified in 18 tribes. The genera are distributed along the whole latitudinal gradient in Chile, with a centre of richness at 33°–34° S. Almost one‐third of the genera show small to medium‐small ranges of distribution, while two‐thirds have medium‐large to large latitudinal ranges of distribution. Of the 115 mainland genera, 46% have their main distribution in the central Mediterranean zone between 27°–37° S. Also of the mainland genera, 53% occupy both coastal and Andean environments, while 33% can be considered as strictly Andean and 20% as strictly coastal genera. The biogeographical analysis of relationships allows the distinction of several floristic elements and generalized tracks: the most marked floristic element is the Neotropical, followed by the antitropical and the endemic element. The biogeographical analysis provides important insights into the origin and evolution of the Chilean Asteraceae flora. The presence of many localized and endemic taxa has direct conservation implications.

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