A taxonomic revision of Hedwigia (Hedwigiaceae, Hedwigiales) in China Huang, Wen-Zhuan Ma, Wen-Zhang Ignatov, Michael S. Ignatova, Elena A. Sulayman, Mamtimin Wu, Yu-Huan Zhu, Rui-Liang Phytotaxa 2024 2024-01-18 634 3 215 234 W.Z.Huang & R.L.Zhu W. Z. Huang & R. L. Zhu. A. Leaves 2024 [136,592,878,905] Bryopsida Hedwigiaceae Hedwigia Plantae Leucodontales 11 226 Bryophyta species sinica sp. nov.    Diagnosis:—Similar to Hedwigia czernyadjevae, but differing in the slenderer leaves with length/width ratio of (2.5−)2.9−3.3(−3.9), sparse hairs at the base of calyptrae, and obovate to obconic capsules that are broadest just below mouths.   Etymology:—The epithet ‘‘sinica’’ is named after China, where this new species was found.     TYPE:— CHINA. Yunnan: Lijiang City, Baisha County, Alpine Botanical Gradentowards Yu-Long Reservoir, 27°0′8″ N, 100°11′13″ E,  3150 m, on rock,  9 Aug. 2021,  W. Z. Ma 21-12332( holotype: KUN!; isotype: HSNU!).   Description:—Plants in loose tufts, dark brown below, yellowish-green above. Stems branched, up to 5 cmlong. Cross-section of stem rounded, consisting of 2–4 layers of smaller, thick-walled outer cortical cells, numerous rows of larger and thinner-walled inner cortical cells, central strand cells not differentiated. Stem leaves spirally arranged, wide-spreading to recurved when moist, erect-spreading when dry, with straight apices, rarely secund. Leaves longovate or lanceolate, (1.8−)2.3−3.0(−3.4)× 0.7−1.1 mm, with length/width ratio of (2.5−)2.9−3.3(−3.9), recurved at lower 3/4 or to the base of hair-point. Hyaline leaf apices 0.4–1.2 mmlong, constituting (15−)30−45% of leaf length, margins of hair-points entire or with few sharp teeth at the distal portion. Abaxial surface of hyaline leaf apices covered with simple and branched papillae; median leaf cells thick-walled, porose, 11−20×5−10 μm, on abaxial surface mainly with single, large, branched, peltate papilla per cell, rarely with two papillae, and on adaxial side with one similar but smaller papilla. Cells in the leaf base linear, porose, 33−67×7−11 μm, with 2−5 simple papillae per cell, alar cells more or less quadrate, 9−18×7−13 μm. Autoicous; male bracts small, apices obtuse or acuminate, 0.63−0.83× 0.33−0.46 mm; perichaetial leaves oblong, gradually narrowed to the apex, broadest slightly above the middle, 4.3−4.7× 1.1−1.3 mm, cilia long, uniseriate distally and 1−3 cells wide in the basal portion. Capsules immersed, obovate to obconic, broadest just below mouths, 1.7−2.0× 1.3−1.6 mm, with immersed stomata at base of the urn; peristome and annulus absent; exothecial cells in the middle of urn rectangular or short rectangular, at urn mouth in several rows smaller and darker colored. Setae 0.05−0.2 mm; calyptrae conical, with sparse hairs at the base. Spores 20−26 μm in diameter, triangular-globular, light brown, with worm-like papillae on the distal surface, proximal face appearing smooth.  Note:—  Hedwigia sinicacould potentially be misidentified as  H. detonsa(M. Howe 1897: 91) W.R.Buck & D.H.Norris (1996: 368),  H. stellata, and  H. czernyadjevaeowing to the presence of one single, branched papilla per cell on abaxial side of median laminal cells in all these species ( Eckel 2014; Ignatova et al. 2016). However, the perichaetial leaf margins in  H. detonsaare entire, lacking cilia at margins, which distinguish this species well ( Buck & Norris 1996; Eckel 2014), whereas perichaetial leaves in  H. sinicaare ciliate (  Fig. 6D).  Hedwigia stellata, which is fairly easy to recognize in nature, is distinguished by its reflexed or recurved leaf tips, giving the shoot tip a starry appearance when dry ( Hedenäs 1994; Buck & Norris 1996; Atherton et al. 2010; Eckel 2014; Ignatova et al. 2016). In contrast,  H. sinicahas straight and erect-spreading leaf tips ( Figs. 5D, 8A). One of the main microscopic characteristics that distinguishes  H. sinicafrom  H. stellatais the presence of porose median laminal cells in the former (  Fig. 6F), while they are smooth, not porose in the latter ( Ignatova et al. 2016). In addition,  H. sinicadiffers from  H. czernyadjevaeby having (1) more slender leaves with a length/width ratio of (2.5−)2.9−3.3(−3.9) (  Figs. 6A), (2) sparse hairs at the base of calyptrae (  Fig. 7B), and (3) obovate to obconic capsules that are broadest just below the mouths (  Fig. 7A). On the other hand,  H. czernyadjevaehas a length/width ratio of (1.7−)2.1−2.6(−3.0) in its leaves (  Fig. 2A; Ignatova et al.2016), calyptrae with strong hairy coverage throughout (  Fig. 3D), and ovate to obovate capsules with the broadest part shortly above the middle (  Fig. 3C).   Distribution and habitat:—This species is found so far only in China, where it typically thrives on marble rock walls in sunny locations, and usually is associated with  Bryoerythrophyllum alpigenum( Juratzka 1882: 98) P.C. Chen (1940: 5),  Bucklandiella subsecunda(Hooker & Greville ex Harvey 1836: 1) Bednarek-Ochyra & Ochyrain Ochyra et al.(2003: 147),  Dicranum flagellare Hedwig (1801: 130),  Herbertus Gray (1821: 678), and  Pseudohygrohypnum calcicola( Ando 1958: 167) Jan Kučera & Ignatovin Kučera et al.(2019: 650), at altitudes ranging from 2830 mto 3511 m.   FIGURE 6.  Hedwigia sinicaW.Z.Huang & R.L.Zhu. A.Leaves; B.Leaf apex; C.Male bract; D.Perichaetial leaf; E.Papillae in mid-leaf on abaxial surface; F.Cell areolation in mid-leaf, showing thick-walled and porose cell walls; G.Papillae in mid-leaf on adaxial surface; H–I.Cells in the middle of leaf base; J.Basal marginal cells. K.Cross section of stem; L.Leaf transverse sections. All from W.Z. Ma 21-12332(holotype).   FIGURE 7.  Hedwigia sinicaW.Z.Huang & R.L.Zhu. A.Capsule; B.Calyptra; C.Exothecial cells in the middle of urn; D.Operculum; E.Stoma; F.Spores. All from W.Z. Ma 21-12332(holotype).  Additional specimens examined:—   CHINA. Sichuan: Ganzizangzu Autonomous Prefecture, Xiangcheng County, along a cascading stream (name not determined), 28°47′49.0″ N, 99°55′00.0″ E,  3500 m, on granitic rock above stream in sun,  23 Sept. 2016,  James R. Shevock48994( KUN);  Ganzizangzu Autonomous Prefecture, Daocheng County, Sheng-Mu Township, along Dao-Cheng Rivernear Ri-Huo Village, 29°2′49.0″ N, 100°33′44.0″ E,  3450 m, on granitic rock,  28 Aug. 2018,  W. Z. Ma18-9821( KUN).   Yunnan: Dali City, Cangshanerhai National Nature Reserve, Xiaoceng Peak, 25°40′46.22″ N, 100°6′24.97″ E,  3213 m, on rock,  6 Sept. 2023,  R. L. Zhuet al. 20230906-37( HSNU); Shangri-La City, Shangri-La County, Luoji County, Ni-Ru Village, along Ni-Ru River, 27°57′16″ N, 100°3′42″ E,  2830 m, on rock,  18 Sept. 2016,  W. Z. Ma16-7782( KUN); Shangri-La City, Shangri-La County, Luoji County, Ni-Ru Village, lower slopes of Pielongshan, along a 10 kmtrail to ‘ Colorful Rainbow Waterfall’of the Ni-Ru River, between second stream crossing and the falls, 27°57′45.0″ N, 100°01′58.7″ E,  3270 m, on marble rock wall in sun to filtered light,  19 Sept. 2016,  James R. Shevock48936( KUN); Shangri-La City, Shangri-La County, Luoji County, along trail from Ni-Ru village to Gu-Zhongpasture,  3060 m, Onrock,  10 Jul. 2023,  W. Z. Ma14476( KUN);  Zhaotong City, Qiaojia County, Yaoshan Town, Yaoshan National Nature Reserve, on the way to the summit, from Dawoto Longtan, 27°12′40.7″ N, 103°5′23.45″ E,  3511 m, on granitic rock in sun,  11 Nov. 2021,  W. Z. Huang& H. Xu20211111-3( HSNU). 2021-08-09 TYPE, W, Z, KUN, HSNU China Baisha County 3150 27.002222 Alpine Botanical Graden 20 100.18694 Lijiang City 11 226 2 Yunnan holotype 2016-09-23 R, KUN James & Shevock China Xiangcheng County 3500 28.796944 Ganzizangzu Autonomous Prefecture 1 99.916664 14 229 1 Sichuan 2018-08-28 W, Z, KUN Ma China Daocheng County 3450 29.046944 Township 1 100.562225 Ganzizangzu Autonomous Prefecture 14 229 1 Sichuan 2023-09-06 R, L, HSNU Zhu China Dali City 3213 25.679504 Xiaoceng Peak 1 100.10693 Cangshanerhai National Nature Reserve 14 229 1 Yunnan 2016-09-18 W, Z, KUN Ma China Luoji County 2830 27.954445 County 20 100.06167 City 14 229 1 Yunnan 2016-09-19 R, KUN James & Shevock China Luoji County 3270 27.962502 County 1 100.032974 City 14 229 1 Yunnan 2023-07-10 W, Z, KUN On & Ma China Luoji County 3060 County City 14 229 1 Yunnan 2021-11-11 W, Z, H, HSNU Huang & Xu China Qiaojia County 3511 27.211306 Yaoshan Town 1 103.08985 Zhaotong City 14 229 1 Yunnan