Selaginella austrotibetica (Selaginellaceae), a new spikemoss from Xizang, China Author Zhang, Meng-Hua State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences (CAS), & National Botanical Garden, Beijing 100093, China & Key Laboratory of Plant Resources Conservation and Utilization, College of Biology and Environmental Sciences, Author Yang, Jie State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences (CAS), & National Botanical Garden, Beijing 100093, China & College of Biology and Food, Shangqiu Normal University, Shangqiu, Henan 476000, China Author Shalimov, Aleksandr Petrovich Altai State University, Lenina Pr., 61, Barnaul 656049, Russia Author Zhang, Jong-Soo Kang and Xian-Chun text Journal of Species Research 2024 13 1 1 9 journal article 10.12651/JSR.2024.13.1.001 2713-8615 13160978 Selaginella austrotibetica X.C. Zhang , sp. nov. ( Figs. 1A and 2 ) MfflṚffi (Zangnan Juanbai) Type. CHINA , Xizang , Mêdog , on moss-covered rocky slope, 95.50°E , 29.66°N , altitude 2067 m , 22 December 2022 , X. C . Zhang et al. , 14089 ( Holotype , PE !) . Diagnosis. This new species is similar to S. sajanensis , such as creeping and slightly thick and shiny leaves, but distinct from it by having anisosporophylls, ventral and dorsal leaves that are ovate or broad-ovate, and an acute apex. Description. Plant epilithic, seasonally green, shortly creeping. Rhizophores restricted to lower part of stem, borne on ventral side in axils of branches, 0.1 mm in diam., 2.5-3.0 mm in length. Main stems branched throughout, terete, not sulcate, glabrous, branchlets sparse. Axillary leaves on branches symmetrical or slightly asymmetrical, ovate, 1.1-1.5 × 0.6-0.7 mm , slightly carinate, base exauriculate, margin entire in basal half, upward slightly ciliolate. Dorsal leaves slightly ascending, asymmetrical, broad-ovate, 0.7-1.0 × 0.6-0.8 mm , slightly carinate, base obtuse to rounded, margin denticulate or very shortly sparsely ciliolate, not membranous, apex acute, the distance between upper and lower two adjacent dorsal leaves are about 2.0 mm. Ventral leaves slightly ascending, asymmetrical, ovate, 1.0-1.3 × 0.6-0.8 mm , margin almost entire or denticulate, apex acute, and the distance between the upper and lower two adjacent ventral leaves is about 1.0 mm. Strobili solitary, terminal; sporophylls slightly dimorphic, dorsal sporophylls asymmetrical, broad-ovate, 0.8-1.3 × 0.5-0.7 mm ; ventral sporophylls ovate, 0.8- 1.3 × 0.5-0.7 mm . Sporangia only borne on the ventral sporophylls in the few already drying and incomplete strobili, only microsporangia are found, micorspores yellowish orange. Distribution and habitat. Selaginella austrotibetica is known so far only from its type location in Mêdog County, Xizang , China , where it creeps on moss-covered rocky cliffs. Etymology. The specific epithet ‘austrotibetica’ refers to its location at South Xizang . Conservation status. Selaginella austrotibetica was found only in a small area with few individuals in Mêdog County, Xizang . Therefore, this species should be considered as Critical Endangered (CR), according to the IUCN Red List guidelines.