Paspalum urvillei Steud. 1853

Paspalum urvillei Steud. (1853: 24) Specimens examined: PORTUGAL. Santa Cruz, Santo António da Serra, S side of Golf Court, half-open grassland on the verge of golf court, an established population with +100 individuals, 17 September 2021, F. Verloove 14150 (BR); Ponta do Sol, mouth of riverlet, beach, a single huge individual, 21 September 2021, F. Verloove 14153 (BR); Ambas as margens na foz da ribeira da Ponta do Sol, formando tufos [Both river banks at the mouth of Ponta do Sol stream, forming tufts], 27 October 2022, J. Silva, J. Ferreira & A. Nóbrega 7397 (MADM). This South American weed has its native range from Bolivia to Brazil and in southern South America. It is widely introduced elsewhere as a forage species in tropical and subtropical regions across the world and has established itself in highly disturbed natural ecosystems, agricultural fields, etc. It is listed as an invasive species in, among others, Hong Kong, Japan, Réunion, U.S.A., Cuba, Australia, New Caledonia and New Zealand. In Europe, it has a limited distribution in the Iberian Peninsula where it is naturalized in both Portugal and Spain (Pinto da Silva 1971, Litzler 1979). In Macaronesia, it is well-known from the Azores (Santa Maria, São Miguel, Terceira; Silva et al. 2005) whereas in the Canary Islands it has only been reported from La Palma (Santos 1983) where it has become a common weed. It is here recorded for the first time from the island of Madeira. Paspalum urvillei is much reminiscent of P. dilatatum Poir., the latter being widely naturalized, especially in lowland parts, in the island of Madeira. Perhaps both have been intermingled up to the present. P. urvillei usually is a taller species, with robust stems up to 2 m tall; its spikelets, however, are smaller (2–3 mm vs. 3–4 mm) and the inflorescence branches are much more numerous (10–25 vs. 2–10). In September 2021, P. urvillei was observed in two localities (see above). At least in Santo António da Serra it looks well-established. It should be looked for elsewhere in the island of Madeira.