ABSTRACT
The family Alismataceae comprises twelve genera of herbaceos aquatic plants. There are only two genera which are naturally found in neotropical regions. Echinodorus and Sagittaria. This study reports the Echinodorus species from Brazilian "caatinga" dominium, a region which is mainly characterized by semiarid climate and intermittent aquatic ecosystems. The following taxa have been identified: E. tenellus, E. glandulosus, E. pubescens, E. subalatus subsp. subalatus, Echinodorus subalatus subsp. andrieuxii; E. palaefolius, E. macrophyllus subsp. scaber, E. grandiflorus subsp. aureus, E. reticulatus, E. lanceolatus e E. paniculatus. Full descriptions, observations, geographic distributions, illustrations and a species key are presented.
Key words:
Aquatic macrophyte; semiarid region; temporary lagoons; monocotyledons