The relationship between the vegetation of discharge areas on the sands of Doñana Biological Reserve and both groundwater chemistry and depth of phreatic water table has been studied. Four types of waters have been detected each maintaining a defined plant community: Very mineralized waters (electrical conductivity > 1500 pS/cm) related to Tamarix canarierzsis and Juncus acutus; mineralized waters (500 pSlcm) related to Scirpus holoschoenus and Jurzcus maritimus; little mineralized waters rich in chloride (400 pS/cm) related to J.efisus, J. acutifZorus and Pteridium aquilirzum; light mineralized waters (<300 pS/cm) related to vegetation which species composition depends on water table depth (deeper water table with Halimium halimifolicim, Stauracarzthus grrzistoides and U1e.x australis, and shallow water table with Erica scoparia, Calluna vulgaris and Llaphlze gnidiinm)