Polish Botanical Journal 55(2): 499–506, 2010 BUCKLANDIELLA SHEVOCKII (BRYOPHYTA, GRIMMIACEAE), AN EXQUISITE NEW SPECIES FROM YUNNAN, CHINA HALINA BEDNAREK-OCHYRA & RYSZARD OCHYRA Abstract. Bucklandiella shevockii Bednarek-Ochyra & Ochyra is described as a new species from five localities in the Gaoli- gong Shan mountains of the Sino-Burmese border region in western Yunnan Province of China. The species is known only in the barren state, with a few perichaetia only, but it exhibits a set of peculiar gametophyte characters, including prominent, pel- lucid, yellow to orange-brownish, lax alar cells forming longly decurrent auricles; a faint, bistratose costa reaching ½−¾ of the leaf length and situated at the bottom of a deep furrow; a distinctly twisted leaf acumen; and a short, hyaline, dentate, flat and twisted hair-point. These traits make it only distantly related to other congeners and therefore a new subsection, Bucklandiella Roiv. subsect. Shevockiella Bednarek-Ochyra & Ochyra, is established to accommodate this new species which on account of the shape of the perichaetial leaves is tentatively placed in Bucklandiella Roiv. sect. Subsecunda (Bednarek-Ochyra) Bednarek- Ochyra & Ochyra. Key words: Bucklandiella, Codriophorus, Racomitrium, Grimmiaceae, Bryophyta, taxonomy, Yunnan, China, Asia Halina Bednarek-Ochyra & Ryszard Ochyra, Laboratory of Bryology, Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Kraków, Poland; e-mails: h.bednarek@botany.pl, r.ochyra@botany.pl INTRODUCTION Yunnan is the fourth province of China in respect of size and it has also an exceptionally rich bryo- flora which consists of 572 species of hepatics (Gao & Cao 2000) and 1024 species of mosses (Li 2002, 2005). These figures are not definite and cur- rent field work continuously yields taxa new to this province and China, for instance Cryptocoleopsis imbricata Amakawa (Wu & Gao 2002), Hydro- cryphaea wardii Dixon (Shevock et al. 2006) and Prasanthus suecicus (Gottsche) Lindb. (Váňa et al. 2010), as well as new to science, for example Shevockia inunctocarpa Enroth & M. C. Ji (Enroth & Ji 2006), Yunnanobryon rhyacophilum Shevock, Ochyra, S. He & D. G. Long (Shevock et al. 2011), Lobatiriccardia yunnannesis Furuki & D. G. Long (Furuki & Long 2007), Gottschelia grollei D. G. Long & Váňa (Long & Váňa 2007), Nardia grollei Váňa & D. G. Long and Solenostoma dulongense Váňa & D. G. Long (Váňa & Long 2009), and Hamatostrepta concinna Váňa & D. G. Long (Váňa & Long 2008). Most of these records are credited to James R. Shevock, San Francisco, Cali- fornia, and David G. Long, Edinburgh, Scotland, who made large collections of bryophytes in the remote Gaoligong Shan mountains in western Yunnan Province during several expeditions or- ganised within a joint biodiversity inventory project developed between the Chinese Academy of Sciences, Kunming, the California Academy of Sciences, San Francisco, and the Royal Botanic Garden, Edinburgh. The project began in 1998 and bryophytes were added to the taxonomic groups to be inventoried in 2002 (Long 2008). Jim Shevock and David Long regularly trans- mitted to us specimens of racomitrialean mosses collected during their expeditions to Yunnan. In the instalment sent to us in 2007 by J. Shevock we found an exquisite specimen of a strange and bizarre species of Bucklandiella Roiv. Additional specimens of the same moss we found in the col- lection from the same area obtained from David Long. Despite its sterility, the moss exhibited a set of unique gametophyte characters which warranted its recognition as a species new to science and we are pleased to dedicate it to our friend Jim Shevock whose specimen of this species we studied first.