Atlas of alien plants of Madrid, II. Nymphaceae-Gramineae

Abstract

In this second part of the atlas of allochthonous flora of Madrid, the Orders Nymphaeales, Magnoliales, Laurales and as well as Monocots plant are included. It has been considered the taxa introduced out of urban areas, parks or gardens, naturalized or not. A total of 101 taxa are analyzed and references to other 39 are included. Of the analyzed taxa, 58 are allochthonous in Madrid (49 naturalized, 8 without evidence of being so and one without specific known localities) and 9 in nearby localities (8 naturalized and 1 without evidence of being so). Another 11 are allochthonous in Madrid and could be naturalized, but there is no evidence of this; 5 appear in gardens and 6 are suspected of their possible presence due to their use in crops or extensive sowing. In 18 taxa there are discrepancies between authors on whether or not they are allochthonous; in this work it has been considered that they are not. Finally, it is proposed to exclude 5 taxa from the allochthonous flora of Madrid. Among the taxa included, Arundo donax is one of the most aggressive invasive plant in the world, Arundo donax. Some taxa are ancient introductions with stabilized or declining populations. There are very few references to naturalized cereals, which may be due to their low persistence. Some species are neocolonizers, like Limnobium laevigatum, the most recently detected, or Cortaderia selloana, in expansion.