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| Asplenium jiulianshanense K.W.Xu & G.L.Xu in Lin, Xu, Jin, Liao & Xu, 2022. 九连山铁角蕨 || DOI: 10.3897/phytokeys.199.81292 |
Abstract
Asplenium jiulianshanense, a new tetraploid fern species of the A. normale complex (Aspleniaceae) from Jiulianshan National Nature Reserve, southern Jiangxi, China is described and illustrated. We inferred the phylogenetic position of the new species based on sequences from seven plastid markers (atpB, rbcL, rps4, rps4-trnS, trnL, trnL-F, and trnG) and one low-copy nuclear gene, pgiC. The plastid phylogeny supported a close relationship among the new species A. jiulianshanense, A. minutifolium, and A. kiangsuense, while the nuclear phylogeny differed in topology from the plastid tree. The new species may be due to hybridization between A. kiangsuense and A. boreale. Morphologically, the new species can easily be distinguished from other members of the A. normale complex by rachises bearing a gemma near the apex, pinna margins entire to sparsely crenate, and (1‒)3‒4(‒6) sori per pinna.
Keywords: Black-stemmed spleenworts, conservation, new taxon, species complex, taxonomy
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| Asplenium jiulianshanense K.W.Xu & G.L.Xu A, B habitat where the new species was discovered C habit D rhizome and roots E irregular branch of lamina F adaxial view of portion of lamina G abaxial view of portion of fertile lamina H frond with a gemma at the distal end of the rachis. |
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| Asplenium jiulianshanense K.W.Xu & G.L.Xu A habit B pinna showing the venation and the distribution of sori C rhizome scale. Scale bars: 2 cm (A); 5 mm (B); 2 mm (C). |
Asplenium jiulianshanense K.W.Xu & G.L.Xu, sp. nov.
Diagnosis: Asplenium jiulianshanense somewhat resembles A. kiangsuense by its small size, rachises adaxially without a deep furrow, pinnae elliptic to trapeziform-oblong, sori 3–4 per pinna in the middle part of frond. However, the former has rachises with only one gemma near apex, pinnae (15‒)20‒35 pairs, pinna margins entire to sparsely crenate, exospore length 37‒43 μm, while the latter has rachises without gemmae near the apex, pinnae 8‒20(‒22) pairs, pinna margins entire to sinuate, exospore length 31‒36 μm.
Etymology: Based on the Chinese pinyin, Jiulianshan, the name of the National Nature Reserve in southern Jiangxi, China, referring to the type locality of the species.
Vernacular name: 九连山铁角蕨 (jiǔ-lián-shān tiě-jiǎo-jué).
Geographical distribution and habit: Asplenium jiulianshanense is known only from a single locality in Mount Jiulianshan, Jiangxi, China, where there have been multiple collections. It was observed to grow on cliff rocks under shrubs at an elevation of ca. 200 m in subtropical evergreen broad-leaved forest.
Chen-Xue Lin, Guo-Liang Xu, Zhi-Fang Jin, Wen-Bo Liao and Ke-Wang Xu. 2022. Molecular, Chromosomal, and Morphological Evidence reveals A New Allotetraploid Fern Species of Asplenium (Aspleniaceae) from southern Jiangxi, China. PhytoKeys. 199: 113-127. DOI: 10.3897/phytokeys.199.81292
