Ehrharta longiflora sm. y Pennisetum setaceum (forsk.) Chiov., dos nuevas gramíneas exóticas para la isla de Madeira (Portugal)

Abstract

The number of introduced and probability introduced taxa in the Madeira and Selvagens islands currently accounts for nearly 36% of the total flora of these archipelagos, including 53 Poaceae taxa (out of 141 total taxa), therefore corresponding to the family with the higher proportion of introduced taxa (38.4%).

The genus Ehrharta Thunb. comprises about 35 species, their native distribution spanning from South Africa to the regions of Ethiopia and Yemen, with one species, E. longiflora Sm., recorded as introduced in Gran Canaria.

The genus Pennisetum Rich. includes ca. 80 species of which a total of 8 species are present in Macaronesia, 6 of them as alien species (Azores, Madeira and Canary Islands), with three: P. clandestinum Hochst. & Chiov., P. purpureum Schum. and P. villosum R. Br. ex Fresen, occurring in the Madeira archipelago.

Ehrharta longiflora Sm. and Pennisetum setaceum (Forssk.) Chiov., are here recorded for the first time for the Madeira island. Both taxa were detected in disturbed areas at low and medium altitudes. Several mature and flowering/fructifying individuals have been found, suggesting that both species are already fully naturalized. Naturalization, invasiveness and ecological impacts are discussed.