Phytotaxa

**Guangxi-Yunnan 2009: Nine new cave ferns of Polystichum (Dryopteridaceae)**

HAI HE, ZHEN-LONG LIANG, LI-BING ZHANG — Wed, 29 Apr 2026 00:00:00 +1200

Based on gross morphology and spore morphology, nine new species of cave ferns of Polystichum subg. Haplopolystichum are described and illustrated from southern China’s Guangxi and Yunnan provinces. These nine new species include P. adclivum, P. crepusculum, P. dilatatisquamosum, P. durispinosum, P. elegantissimum, P. longidentatum, P. tenuirachis, P. tianlinense, and P. zhenxiongense. All nine species each are so far known only from a single cave; these nine are all classified as Critically Endangered (CR) following IUCN Red List criteria.

**Discovery of Comarum palustre L. (Rosaceae) in Iranian alpine refugia highlights conservation needs of mountain wetlands**

MINA KHORASANI, AMIR TALEBI, MORTEZA DJAMALI, ALIREZA NAQINEZHAD — Wed, 29 Apr 2026 00:00:00 +1200

Comarum palustre, a circumpolar boreo-temperate helophytic species of the monotypic genus, is recorded here for the first time from continental Southwest Asia (Iranian Plateau). The species was collected from a peat bog developed within Lake Almalou, a volcanic crater lake situated in the northwest of Iran. Despite extensive explorations of wetlands and mire vegetation across Iran, no other populations of C. palustre have been detected, underlining its extreme rarity in the region. The discovery of this species in an isolated wetland at the southernmost edge of its distribution range highlights the role of Quaternary climatic oscillations in shaping its distribution, as well as the importance of such interglacial refugia for conserving isolated populations of cold-adapted plant species in low-latitude mountain systems. This finding underscores the need for careful taxonomic work in low-latitude biodiversity hotspots to uncover hidden diversity and to inform conservation of vulnerable aquatic ecosystems. A comprehensive description, with taxonomic and ecological notes, illustrations, and a conservation assessment following IUCN guidelines, is provided. Furthermore, distribution maps of C. palustre are also presented here, along with key differences from its closest relative.

**A new Centaurea species (sect. Centaurea) from south-western Türkiye**

TUNA UYSAL, MERYEM BOZKURT, EMRAH ŞIRIN, KUDDISI ERTUĞRUL — Wed, 29 Apr 2026 00:00:00 +1200

Centaurea stadiae Uysal (sect. Centaurea) is described as new to science from Türkiye. Morphology, especially seed surface, karyology and molecular data were used to distinguish the new species from its presumed relatives. The new taxon appears morphologically similar to C. pelia which is endemic to Greece but is clearly separated mainly by having corymbose inflorescence and numerous flowers as well as more narrow involucres and reddish narrow and triangular appendage borders. Moreover, C. stadiae is a tetraploid species unlike C. pelia with a diploid chromosome number. Although the new species appears similar to C. dichroa, it can be easily distinguished by its dirty white flowers, triangular appendages, and smaller achenes. Additionally, a modified identification key is provided, and the species ecology and phenology are given.

Carex mazuilingensis (Cyperaceae), a new sedge from Hainan Island of South China

HU-BIAO YANG, SHU-PENG DONG, QING-LONG WANG, JIN-HUA CHEN, YUAN-YUAN WU — Wed, 29 Apr 2026 00:00:00 +1200

A new species of Carex sect. Radicales, C. mazuilingensis, from Hainan, South China, is described and illustrated. The new species is similar to C. planiscapa, but differs in its much longer leaves and culms, wider culms (ca. 3 mm), sheath-like involucral bracts with extremely degenerate blade, inflorescence with solitary obovoid to broadly ovoid and densely flowered spike, ca. 6 mm long and densely pubescent utricles, and ca. 5 mm long nutlets with a ca. 1.5 mm long stipe at base.