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| Polystichum cretaceum Xiaohua Chen & Y.F.Gu, in X.-H. Chen, Shu, Xu, Liu, L.-J. Chen, He, Zheng et Gu, 2025. 白垩柳叶耳蕨 | DOI: doi.org/10.11646/phytotaxa.690.2.8 |
Abstract
Polystichum (Dryopteridaceae) is a cosmopolitan fern genus known for its rich species diversity, with its primary diversity center in eastern Asia. In this study, we describe a novel species, Polystichum cretaceum, discovered in Napo County, Baise City, Guangxi Zhuang Autonomous Region, China. This species is distinguished by its dwarf habit, fronds simple or 1-pinnate (pinnae 2–4 pairs), pilose or glabrous surface, and fenestrate perispores. This new species resembles P. fraxinellum but differs by having oval pinnae with entire margins and free veins, while P. fraxinellum has ovate-lanceolate pinnae with slightly recurved margins and anastomosing veins. Phylogenetic analysis suggests a close relationship between P. cretaceum and P. minimum. However, P. minimum differs in having obliquely ovate lateral pinnae with shallowly incised-toothed margins and acuminate apices.
new taxon, Cyrtogonellum, ferns, species diversity, Pteridophytes, rbcL gene, chloroplast genome
Polystichum cretaceum Xiaohua Chen & Y.F.Gu sp. nov.
Etymology:—The specific epithet “cretaceum” is derived from the habitat of this newly identified species, which thrives on moist, chalky soil slopes.
Vernacular name:—白垩柳叶耳蕨 (bai e liu ye er jue)
XIAO-HUA CHEN, JIANG-PING SHU, YI-DA XU, HONG-MEI LIU, LI-JUN CHEN, JIAO HE, XI-LONG ZHENG and YU-FENG GU. 2025. Polystichum cretaceum (Polystichum sect. Cyrtogonellum, Dryopteridaceae), A New fern from Guangxi, China. Phytotaxa. 690(2); 276-284. DOI: doi.org/10.11646/phytotaxa.690.2.8 [2025-02-28]
