A review of Calypogeia (Marchantiophyta) in the eastern Sino-Himalaya and Meta-Himalaya based mostly on types Author Bakalin, Vadim A. Botanical Garden-Institute, Vladivostok, Russia https://orcid.org/0000-0001-7897-4305 vabakalin@gmail.com Author Klimova, Ksenia G. Botanical Garden-Institute, Vladivostok, Russia https://orcid.org/0000-0002-3229-1880 Author Nguyen, Van Sinh Institute of Ecology and Biological Resources, Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Ha Noi, Vietnam text PhytoKeys 2020 153 111 154 http://dx.doi.org/10.3897/phytokeys.153.52920 journal article http://dx.doi.org/10.3897/phytokeys.153.52920 1314-2003-153-111 475172DBEA915C52B9909334D3DB5478 Calypogeia asakawana S. Hatt. ex Inoue, J. Jap. Bot. 39 (4): 107. 1964. Figure 9A-D = Calypogeia okamurana Steph. ex Bonner, Index Hepaticarum 3: 501, 1963 (nom. inval., Art. 38.1(a), no description). Authentic material: Japan. Iyo: Tokonabe Mt., 30 March 1913, S. Okamura no. 383 (original material, probably scheduled as the type: G [G00067726!], the specimen in all ways is similar to C. asakawana ). Type. Japan. Tokyo: Asakawa Experimental forest, 12 June 1954, U. Mizushima, no. 5 (holotype: TNS [TNS-174359!]; isotype NICH [NICH-55582!]). Remarks. The species is regarded as Japanese endemic (known in Honshu only, cf. Yamada and Iwatsuki 2006 ) and is characterized morphologically by small, deeply divided, bifid and spreading underleaves (slightly wider than stem) and rounded leaf apices. The description based on the holotype is as follows: plants pale brownish in herbarium, prostrate, translucent, slightly glistening, 1.1-1.5 mm wide and 8-20 mm long, forming loose mats; rhizoids rather numerous, originating as several unclear fascicles near underleaf bases and obliquely to erect spreading, attaching plants to the substratum; stem brownish (in the herbarium), 100-160 µm in diameter, branching not seen; leaves subhorizontally inserted, dorsally insertion line subtransverse to loosely arcuate, ventrally decurrent for 1/2-2/3 of stem width, obliquely lingulate, to obliquely ovate-lingulate, slightly convex to planar, slightly undulate along margin, laterally spreading, 650-700 x 400-550 µm , leaf apex rounded; underleaves loosely sinuately to transversely inserted, shortly decurrent (up 1/3 of stem width), 120-170 x 200-220 µm , bilobed by U-shaped sinus descending to 2/3 of leaf length, undivided zone 1-2 cells, lobes in the base 3-5 cells wide, midleaf cells oblong, thin-walled, 32-62 x 20-33 µm , trigones vestigial, cuticle virtually smooth; cells along leaf margin subquadrate to oblong, 20-38 µm , thin-walled, with very small concave trigones, cuticle smooth. Figure 9. Calypogeia asakawana S.Hatt. ex Inoue: A plant habit, fragment, ventral view B, C underleaves D Leaf Calypogeia ceylanica S.Hatt. et Mizut.: E, F leaves H underleaf J leaf middle cells Calypogeia cuspidata (Steph.) Steph. G plant habit, fragment, ventral view I underleaf L leaf M leaf middle cells Calypogeia decurrens (Steph.) Steph.: K plant habit, fragment, ventral view. Scale bars: 2 mm ( G ); 1 mm ( E, F, K ); 500 µm ( A, D, L ); 200 µm ( H, I ); 100 µm ( B, C ); 50 µm ( J, M ). A from Holotype TNS-174359; B, C, D from authentic material of C. okamurana Steph. nom. herb., G00067726; E, F, H, J Isotype G00064248, G, I, L, M from Lectotype G00069713; K from Isotype G00060745.