Rice field flora and vegetation in the provinces of Valencia and Tarragona

Abstract

Twenty nine emergent and twenty floating or submerged taxa , were found in the rice fields in Valencia and Tarragona provinces. Eleven of the se taxa, all them emergent, are alien Of introduced ones. Echinochloa oryzoides and E. oryzicola are the most important in both areas, together with Cyperus difformis and Echinochloa hispidula in Valencia. The remaining thirty eight taxa belong to the native flora. There are predominantly the emergent Scirpus maritimus, Alisma plantago-aquatica. Echinochloa crus-galli and Paspalum distichum; the floating Lemna minor and L. gibba; the submersed Potamogeton nodosus; Zannichellia palustris and Najas minor; and the macroscopical algae Chara vulgaris, Cladophora glomerata, Oedogonium capilliforme, Spirogyra spp., Pithophora oedogania and Hydrodictyon reticulatum. The flora evolution during the last years is analyzed and the present weed communities are studied. The contribution of the different phytosociological classes to the rice field weed flora is presented.