Rediscovery and Redescription of the Enigmatic Radula visianica (Porellales, Marchantiophyta)

Abstract

Abstract: Kockinger, H. 2016. Rediscovery and redescription of the enigmatic Radula visianica (Porellales, Marchantiophyta). — Herzogia 29: 625–634. The supposedly extinct liverwort Radula visianica was rediscovered in the southern and north-eastern Austrian Alps. It was found in five localities, growing on cold, moist, north-facing dolomite rocks in the upper montane and subalpine belts. The new material proved highly variable and only a minority of it comes close to the type material, which is perhaps unsurprising since that originated from a much warmer area at the southern rim of the Italian Alps. An emended description of the species is presented. R. visianica is characterized by its small size, a Lejeunea cavifolia-like habit, the usual absence of gemmae, spreading lobes and in particular an enormous variability in lobule shape which ranges from strongly saccate and shortly orbicular in cold and exposed sites to sickle-shaped and extended to a fine apex in warmer, moister and protected sites. It is ...