SMALL-CELLED NUPELA SPECIES FROM NORTH AMERICA

Abstract

Three small-celled Nupela species were found in streams and moist habitats of the United States, with a concentration of locations in the eastern part of the country. Two new species are described here: N. neglecta Ponader, Lowe & Potapova and N. Carolina Potapova & Clason. These two species and Nupela wellneri (Lange-Bertalot) Lange-Bertalot have external hymenate occlusions of their areolae, which apparently are diagnostic for this genus. These often erode during sample preparation, and hence have not been previously recognized as a generic character. All three species were recorded primarily from epilithon and epiphyton of small, heavily shaded streams with low to moderate conductivity, and relatively high concentrations of dissolved silica, total nitrogen, and dissolved organic matter.