New record of an alien grass, Ehrharta erecta Lam. (Poaceae), for the island of Madeira (Portugal)

Abstract

The panic veldt grass, Ehrharta erecta Lam., is recorded herein for the first time from the island of Madeira. Several populations of this alien grass have been found in several localities of the island, indicating its naturalization. Once present in a region, E. erecta is able to spread relatively quickly because its seeds can be easily dispersed by wind or water over short distances, or by birds and human activities over longer distances. Its vector of introduction to the island of Madeira is unknown, since the plant is apparently not used as an ornamental species, in agriculture, or in the local ethnobotany. Given the locations where it was found, this neophyte was most likely, introduced accidentally as a soil contaminant in the pots of ornamental, exotic plants or mixed with forage plant seeds. In Madeira, E. erecta may become invasive in low altitude, natural habitats or in the surrounding areas, blocking natural processes of secondary ecological succession. Its potential for invasiveness must be monitored.