Distichophyllum chenii B.C.Ho sp. nov. (Daltoniaceae) from Southeast China Boon-Chuan Ho 1,2 1 Department of Biology, Duke University, Durham, NC, USA, 2 Nees-Institut fu ¨r Biodiversita ¨t der Pflanzen, Rheinische Friedrich-Wilhelms-Universita ¨t Bonn, Germany Despite the genus Distichophyllum having been revised recently for the Moss Flora of China, upon examination of a wide range of both Chinese and non-Chinese material a distinct new species was found among existing specimens collected from China. The new species, Distichophyllum chenii, is described based on specimens previously misidentified and reported as Distichophyllum cirratum var. cirratum. Published illustrations of D. cirratum var. cirratum based on a misidentified collection of D. collenchymatosum are highlighted to avoid further future taxonomic confusion. Keywords: Distichophyllum cirratum, Distichophyllum collenchymatosum, Illustration, Misidentification, Moss taxonomy Introduction The recent completion of the eight-volume Moss Flora of China is a major achievement, providing a much-needed framework for future study of the Chinese moss flora. A revision of the Hookerialean genus Distichophyllum Dozy & Molk. is included within the flora (Lin & Tan, 1995, 2002). While evaluating the taxonomy of the genus on a worldwide basis, specimens of the species complex surrounding D. nigricaule Mitt. ex Bosch & Sande Lac. and D. collenchymatosum Cardot were examined and verified. Two specimens, namely Wu et al. 1298 and Lin et al. 4061, were listed by Lin & Tan (1995) in their treatment of D. cirratum Renauld & Cardot var. cirratum, a name which the author considers con- specific with D. nigricaule. However, after careful comparison of these specimens with the type and with non-type specimens of related species of Distichophyllum from the Himalayan and East Asian regions, Wu et al. 1298 (FH!) is confirmed to be D. collenchymatosum, consistent with the earlier identification label subsequently annotated prior to the study of Lin & Tan (1995). This particular misidentified collection from Guangxi has also been illustrated as D. cirratum var. cirratum in Lin & Tan (1995, Figure 27A–D) and in the Moss Flora of China 6 (Lin & Tan, 2002, Plate 400: 1–4). On the other hand, Lin et al. 4061 (FH!), collected from Hainan, does not belong to D. nigricaule, D. collenchymatosum, or to any of their many recognized varieties, based on a careful comparison of types and numerous non-type specimens of the latter two species including their many synonyms. Another representa- tive collection reported for D. cirratum var. cirratum in the Moss Flora of China 6, Wu et al. 419 (FH!), is also identical to Lin et al. 4061 (FH!). Together with a third collection (Z.-H. Li WLL85246, deposited in both H and PE), this material represents a distinct species of Distichophyllum new to science. Interestingly, the duplicate of Z.-H. Li WLL85246 at PE has been identified as D. cf. cuspidatum (Dozy & Molk.) Dozy & Molk., while the specimen deposited in H has been annotated as D. collenchymatosum. From the date, 7 July 1985, it can be deduced that this collection was probably made during the same field excursion as Lin et al. 4061, which was collected 2 days later on the same mountain. Distichophyllum chenii B.C.Ho, sp. nov. (Figure 1) Distichophyllum cirratum var. cirratum P.-J. Lin & B.C. Tan, Harvard Pap. Bot. 7: 35. 1995 pro parte; P.- J. Lin & B.C. Tan Moss Fl. China 6: 16. 2002 pro parte; auct non Renauld & Cardot, Rev. Bryol. 23: 104. 1896 Type: CHINA, Hainan Isl., Ledong Co., Mt. Jianfengling, on rocks, 870 m, 7 July 1985, Z.-H. Li WLL85246 (85-120) (Holotype: H 3049760!, Isotype: PE 01075820!) Description: Plants large, dark dull green, forming wefts. Shoots prostrate, simple or sparingly branched. Stems thick, up to 700 mm across, dark reddish brown, in cross section elliptical. Axillary hairs filiform, up to 2 per leaf, consisting of 3–4 cells, ca 100 mm long and 22–28 mm across; basal cell 20 mm long; intermediate cell 2–3, 30 mm long; terminal cell Correspondence to: B-C Ho, Nees-Institut fu ¨ r Biodiversita ¨ t der Pflanzen, Rheinische Friedrich-Wilhelms-Universita ¨t Bonn, Meckenheimer Allee 170, 53115 Bonn, Germany. Email: calyptrochaeta@yahoo.com 180 ß British Bryological Society 2013 DOI 10.1179/1743282013Y.0000000061 Journal of Bryology 2013 VOL. 35 NO.3