Reinstatement of Loxogramme yigongensis (Polypodiaceae), an endemic species from southeastern Xizang, China Author Yang, Jian-Jun 0000-0002-4994-6345 School of Ecology and Environmental Science, Yunnan University, Kunming, 650091 Yunnan, China. & yjj 2514 @ mail. ynu. edu. cn; https: // orcid. org / 0000 - 0002 - 4994 - 6345 yjj2514@mail.ynu.edu.cn Author Wan, Xia 0000-0001-8312-6917 Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization, Chengdu Institute of Biology, Chinese Academy of Sciences, P. O. Box 416, Chengdu, Sichuan 610041, China. & wanxia @ cib. ac. cn; https: // orcid. org / 0000 - 0001 - 8312 - 6917 wanxia@cib.ac.cn Author Zhao, Wang-Lin 0000-0003-0042-2361 CAS Key Laboratory of Alpine Ecology, Institute of Tibetan Plateau Research, Chinese Academy of Sciences (CAS), Beijing 100101, China. & zhaowanglin @ itpcas. ac. cn; https: // orcid. org / 0000 - 0003 - 0042 - 2361 zhaowanglin@itpcas.ac.cn Author Liang, Zhen-Long 0000-0002-9848-5055 Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization, Chengdu Institute of Biology, Chinese Academy of Sciences, P. O. Box 416, Chengdu, Sichuan 610041, China. & liangzl @ cib. ac. cn; https: // orcid. org / 0000 - 0002 - 9848 - 5055 liangzl@cib.ac.cn Author Zhang, Liang 0000-0003-3784-3135 CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences (CAS), Kunming 650201, Yunnan, China. & zhangliang @ mail. kib. ac. cn; https: // orcid. org / 0000 - 0003 - 3784 - 3135 zhangliang@mail.kib.ac.cn text Phytotaxa 2022 2022-07-19 555 1 95 102 http://dx.doi.org/10.11646/phytotaxa.555.1.7 journal article 101786 10.11646/phytotaxa.555.1.7 d67ff38f-48f0-48e3-a874-05431d1ede54 1179-3163 6875787 Loxogramme yigongensis Ching & S. K. Wu (1983: 351) , Fig. 1 Type:— CHINA . Xizang : Bomi County , Yigong Xiang , elev. 2000 m , in dense forests, 15 July 1965 , T.-C. Yin & D.-Y. Hong 0598 ( holotype , PE-01185170 !; isotypes, PE-01185166!, PE-01185167!, PE-01185168!) . Description: —Plant small, 8–15 cm . Rhizome long creeping, slender, ca. 0.5–1.1 mm in diam., densely covered with scales; scales lanceolate, brown, ca. 1.1–1.5-1.2 × 0.3–0.6 mm , margins slightly dentate. Fronds closely spaced or distant, monomorphic; stipe very short or indistinct; lamina simple, succulent, spongy adaxially and abaxially, becoming rugose on both surfaces when dry, 7–14 × 0.5–1.0 cm, widest near middle, apex acute, base gradually narrowed and decurrent; costa obviously raised adaxially, slightly raised abaxially; veins hidden, anastomosing. Sori 3-6 pairs, ca. 10–20 ° from costa, confined to middle-upper part of lamina, 3–12 × 1–1.5 mm , elongate, close and subparallel to costa, slightly sunken; one sporangium with 64 spores when mature. Spores globose, small tuberculate, trilete. FIGURE 3 . Maximum likelihood phylogeny of Loxogramme based on five plastid markers ( rbcL , rps4 , rps4-trnS , trnL , trnL-F ). Maximum likelihood bootstrap support (MLBS) and Bayesian inference posterior probability (BIPP) are given on the left and right along the branches. Voucher information is indicated in blue, geographical provenances are indicated after voucher in black. Distribution and habitat: — Loxogramme yigongensis is narrowly distributed in southeastern Xizang , China . Presently only five populations are known to us, including one population rediscovered near the type locality in Yigong Xiang of Bomi County, and four newly discovered populations in Beibeng Xiang and Bangxin Xiang of Medog County. It grows on old tree-trunks or rocks in primary forests, at elevations between 2200 and 2600 m . High humidity is necessary for the growth of the species. IUCN Red List category :—EN-ENDANGERED (CR B1ab(iii) + D) following the IUCN (2021) criteria: five populations on rocks or tree trunks with about 280–320 plants in total was observed in the field. Additional specimens examined: — CHINA . Xizang : Bomi County , Yigong Xiang , elev. 2500 m , on rocks in broadleaved evergreen forests near a large river, 15 June 2021 , L . Zhang, X . Wan & J .- J . Yang 4105 ( KUN , PYU ); Medog County , Beibeng Xiang , elev. 2000 m , on a tree trunk in broadleaved evergreen forests near a large river, 16 October 2017 , L . Zhang , W .- B . Ju & H .- N . Deng 2130 ( KUN ); Medog County , Bangxin Xiang , elev. 2600 m , on an old tree-trunk in broadleaved evergreen forests of primary vegetation, 17 June 2021 , L . Zhang, X . Wan & J .- J . Yang 4169 ( KUN , PYU ) .