Calypogeia muelleriana (Schiffn.) Muell .Frib., Beih. Bot. Centralbl. 10 (4/5): 217. 1901.

Bakalin, Vadim A., Klimova, Ksenia G. & Nguyen, Van Sinh, 2020, A review of Calypogeia (Marchantiophyta) in the eastern Sino-Himalaya and Meta-Himalaya based mostly on types, PhytoKeys 153, pp. 111-154 : 111

Calypogeia muelleriana (Schiffn.) Muell.Frib., Beih. Bot. Centralbl. 10 (4/5): 217. 1901.

Basionym.

Kantius muellerianus Schiffn., Sitzungsber. deutsch. naturwiss.-med. Vereins Böhmen “Lotos” Prag 48: 342. 1900.

Original material.

Czech Republic, Bohemia, Schiffner; not seen.

Remarks.

This boreal species was originally described from the border between the Czech Republic and German Bavaria (Bohemian Forest) and was found to have circumpolar distribution in the hemiarctic and boreal zones of the Northern Hemisphere. However, even in the hemiboreal zone of East Asia (e.g., in the southern Russian Far East at 43-48°N), the species rarely occurs. Calypogeia muelleriana seems to be hardly possible even in Northeast China, as mentioned by Piippo (1990). Two recent reports from Guangxi and Jiangxi Provinces of China ( Zhu and So 2003; Fang et al. 1998) may belong to other taxa, such as C. apiculata , C. sinensis , and C. granulata , whose distribution in the Sino-Himalaya is underestimated. The distinct differentiation features of C. muelleriana are highly undivided underleaf lamina (4-5 and more cells high), rounded to rarely obtuse leaf apices and grayish to colorless botryoidal oil bodies. The European materials of Calypogeia muelleriana are split into two different and perhaps cryptic taxa ( Buczkowska 2010, Buczkowska and Bączkiewicz 2011).