Festuca tomanii sp. nov., a fescue of sand dunes of the valleys of the northern Upper Rhine, the middle main and the bohemian Elbe

Abstract

Blue green tetraploid fescues growing on base rich sands of the northern Upper Rhine valley, middle Main valley and Czech Elbe valley – previously addressed as F. duvalii – are described as F. tomanii. F. tomanii differs from F. duvalii by (1) parchment-like sheaths of the basal leaves, of which blades drop early (F. duvalii: sheaths of the basal leaves not parchment-like, blades long time lasting), (2) thicker leaves (0.8–1.1 mm vs. 0.6–0.9 mm) with more vascular bundles (9–11 vs. 7) and (3) by a ± continuous sclerenchyma (F. duvalii: sclerenchyma mainly in three bundles). Most populations exist at relic sites and are declining. F. tomanii is a typical part of the Jurineo cyanoidis-Koelerietum glaucae (Koelerion glaucae).