Autecology and distribution of Isoetes longissimum in Europe

I. longissimum is a rare aquatic pteridophyte known only from the NW Spanish region of Galicia and from Algeria. The authors mapped the distribution of this species in Galicia, and investigated the relationships between its presence or absence and water quality variables. I. longissimum is present in 16 10 × 10km grid squares in Galicia, largely in the western central part of the region. Within Galicia, I. longissimum shows a significant preference for sites with low sulphate, ammonium and phosphate concentrations. -Authors