Calamagrostis lonana (Poaceae): a new grass species from the Pennine Alps (Switzerland)

Calamagrostis lonana Eggenb. & Leibundg. (Poaceae) is described as a new alpine grass species from the Pennine Alps. Unlike other Central European Calamagrostis Adans. species, it is only 13–18 cm high and has so far been found only on the high plateaus of the Pas de Lona, along the Torrent de Lona. Compared to similar species, the panicle is only faintly tinged purplish, has remarkably short panicle branches, and thus remains narrow and elongated even when open. The spikelets show callus hairs that only reach about halfway up the lemmas, and these have a short, dorsal awn. The species is probably closely related to the arctic C. stricta (Timm) Koeler, which has only a few relict occurrences in Central Europe. However, it is morphologically well separable. The morphological description of the species is completed by information on the distribution, habitat, soil conditions, and potential threats of C. lonana.