A review of the Gymnostomum calcareum Nees & Hornsch. complex (Bryopsida: Pottiaceae) in southern Europe and the Macaronesian Islands, including G. calcareum var. atlanticum var. nov.

Abstract

New taxonomic observations, based on rhizoidal and protonemal gemmae of material from southern Europe and the Macaronesian Islands, are given in this work for sibling taxa of the Gymnostomum calcareum Nees & Hornsch. complex. Gymnostomum calcareum var. atlanticum Sérgio from the Iberian Peninsula, Madeira and Azores is described as a new variety, and its diagnostic characters are described and illustrated. This moss has a bistratose margin in the upper parts of the perichaetial and vegetative leaves, and the perichaetial leaves are markedly acute. It is closely related to Gymnostomum lanceolatum Cano, Ros & J. Guerra, here reduced to a variety of G. calcareum. The occurrence of fusiform or claviform protonemal gemmae provides a diagnostic feature for the different taxa.

Keywords:

• GYMNOSTOMUM CALCAREUM
• G. LANCEOLATUM
• IBERIA
• MADEIRA
• AZORES