Research Article |
Corresponding author: Xin-Cheng Qu ( qxc20050723@163.com ) Corresponding author: Ri-Hong Jiang ( jiangrhg@163.com ) Academic editor: Blanca León
© 2024 You Nong, Li-Qun Lei, Zi-Yi Zhao, Gui-Yuan Wei, Chuan-Gui Xu, Bin Feng, Xin-Cheng Qu, Ri-Hong Jiang.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Nong Y, Lei L-Q, Zhao Z-Y, Wei G-Y, Xu C-G, Feng B, Qu X-C, Jiang R-H (2024) Cyrtomium adenotrichum (Dryopteridaceae), a new species from Guangxi, China. PhytoKeys 243: 199-207. https://doi.org/10.3897/phytokeys.243.127579
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Cyrtomium adenotrichum Y. Nong & R.H. Jiang (Dryopteridaceae), a new species from Guangxi, China, is described and illustrated. This new species is similar to C. nephrolepioides (Christ) Copel., C. obliquum Ching & K. H. Shing ex K. H. Shing, C. sinningense Ching & K. H. Shing ex K. H. Shing and C. calcis Liang Zhang, N.T.Lu & Li Bing Zhang in having erect rhizomes, dense, leathery lamina and rounded sori, but it can be easily distinguishable by its stipe sparsely glandular, base obvious oblique, basiscopic base truncate, acroscopic base auriculate or ovate.
Gully, limestone, Nandan, new species, taxonomy
Cyrtomium (
During our field surveys conducted in Nandan County, Guangxi, in March 2024, we encountered a unique population of Cyrtomium that exhibited morphological similarities to the species C. nephrolepioides (Christ) Copel.(
The new species was described based on field observations made in March and examination of herbarium specimens at GXMI. Other related Cyrtomium species were examined based on online images from Kew Herbarium Catalogue (http://apps.kew.org/herbcat/gotoHomePage.do) and JSTOR Global Plants (http://plants.jstor.org/) and PE, IBK and KUN. Morphological characters that distinguish it from all other species in the genus of Cyrtomium are used. We also observed living plants of the new species. We observed characters of rhizome, leaves, pedicels, stipe, lamina, scales, sori, indusia.
Descriptions were written from herbarium specimens. Measurements were made with a tape–measure and callipers. The structure of the indumentum and its distribution was observed and described under a dissecting microscope at magnifications of more than 20×. Additional information on locality, habitat, ecology, plant form and fruits were collected in the field and taken from herbarium labels. Conservation threat assessment followed IUCN Categories and Criteria (
Cyrtomium adenotrichum is similar to C. nephrolepioides, C. obliquum, C. sinningense and C. calcis, but differs in its stipe sparsely glandular (vs. glabrous). In addition, it can be distinguished from C. sinningense by its scale margins fimbriate (vs. dentate), lateral pinnae 5–10 pairs (vs. 1–4 pairs), indusia margins dentate (vs. subentire); it can also be distinguished from C. nephrolepioides by its lateral pinnae 5–10 pairs (vs. 10–26 pairs), base obvious oblique (vs. cordate or sometimes obliquely cordate). It differs from C. obliquum by its scale margins fimbriate (vs. dentate), lateral pinnae 5–10 pairs (vs. 12–21 pairs), indusia margins dentate (vs. entire). It can be distinguished from C. calcis by its base obvious oblique (vs. cordate to hastate), lateral pinnae thin leathery (vs. thick leathery). Comparative morphological differences among all five species are presented in Table
Main morphological differences amongst Cyrtomium adenotrichum and C. nephrolepioides, C. obliquum, C. sinningense and C. calcis.
Morphological traits | C. adenotrichum | C. nephrolepioides | C. obliquum | C. sinningense | C. calcis |
---|---|---|---|---|---|
Plant height | 5–15 cm | 12–28 cm | 20–35 cm | 8–12 cm | 13–23 cm |
Stipe | 3–10 cm, 1 mm in diam., sparsely glandular | 3–10 cm, 1–2 mm in diam., glabrous | 6–10 cm, 1–2 mm in diam., glabrous | 5–7 cm, 1 mm in diam., glabrous | 15 cm, 1–3 mm in diam., glabrous |
Scales margins | fimbriate | fimbriate | dentate | Dentate | fimbriate-dentate |
Lamina | linear-lanceolate, 5–10 × 1.5–2 cm | linear-lanceolate, 10–25 × 2–5 cm | lanceolate, 13–35 × 3–5 cm | ovate or oblong-lanceolate, 3–7 × 2.5–3 cm | lanceolate-oblong, 13–23 × 1.9 cm |
Lateral pinnae | 5–10 pairs | 10–26 pairs | 12–21 pairs | 1–4 pairs | 9–14 pairs |
Pinnae | 0.8–1 × 0.4–0.6 cm | 1–2.5 × 0.6–1.2 cm | 2–3 × 1–1.5 cm | 1.2–1.6 × 1–1.2 cm | 1.5–3.5 × 1.2–1.9 cm |
Base | obvious oblique | cordate or sometimes obliquely cordate | oblique | broadly cuneate | cordate to hastate |
Texture | thin leathery | thick- leathery | leathery | Leathery | thick leathery |
Venation | midrib flat or slightly concave on both surfaces | midrib concave on both surfaces | slightly raised abaxially, slightly concave adaxially | indistinct on both surfaces | obscure |
Rows of areolae | 1 or 2 | 2 or 3 | 2 | 2 or 3 | 2, 3, rarely to 4 |
Indusia margins | dentate | subentire | entire | subentire | dentate |
Plants perennial, evergreen, 5–15 cm tall. Rhizome short and erect, together with basal stipe densely scaly. Scales brown, ovate; Leaves clustered, petiole 1–3 cm, stipe stramineous, 3–10 cm, 1 mm in diam, sparsely glandular, densely scaly; scales brown, ovate or lanceolate, margins fimbriate. scales on stipe base brown, ovate or lanceolate, membranous, ca. 8–12 × 1–3 mm, margin minutely denticulate and slightly long ciliate, upword gradually narrowed, subulate, linear-lanceolate. Lamina linear-lanceolate, 5–10 × 1.5–2 cm, base not contracted, 1-imparipinnate; Lateral pinnae 5–10 pairs, crowded, alternate, spreading or slightly ascendant, shortly stalked, ovate or rarely deltoid-lanceolate; lower and middle pinnae 8–10 × 4–6 mm, respectively, subopposite or alternate, apex rounded, base obvious oblique, basiscopic base truncate, acroscopic base auriculate or ovate, margins entire and often slightly reflexed, sparse hairlike scales adaxially and abaxially; terminal pinna ovate, with 1 or 2 connate lobes at base, 20–35 × 15–25 mm; rachis c. 1 mm in diam, sparsely glandular, grooved adaxially, scaly abaxially; scales on rachis brown, linear to subulate, margins sparsely toothed or fimbriate; frond texture thin leathery; venation pinnate, midrib flat or slightly concave on abaxially and adaxially, lateral vein connection, indistinct, lateral veins anastomosing to form 1 or 2 rows of areoles on each side of midrib. Sori 1 row on each side of midrib; indusia margins dentate.
Cyrtomium adenotrichum Y. Nong & R.H. Jiang A, B plant C, D lamina (adaxially and abaxially view) E, F sori and indusia G, H terminal pinna (adaxially and abaxially view) I lateral pinnae (abaxially view, showing: margins entire and often slightly reflexed) J stipe (sparsely glandular) K curled leaves L, M, N scales O curled leaves (sparsely glandular) (Photographed and edited by You Nong).
The specific epithet refers to the stipe sparsely glandular of the new species.
Known only from the north of Guangxi, China (Fig.
Only one population with 10 individuals of Cyrtomium adenotrichum is currently known from Nandan County, Guangxi China. Due to its rarity, the low number of individuals and habitat vulnerability, C. adenotrichum is considered to be Critically Endangered (CR), according to the IUCN (
We are grateful to Lan Xiangchun for fieldwork assistance and Qu Xincheng for the line drawing (Guangxi Institute of Traditional Medical and Pharmaceutical Sciences, Nanning).
The authors have declared that no competing interests exist.
No ethical statement was reported.
This work was supported by the Guangxi High-Level Key Disciplines Construction Pilot Project in Traditional Chinese Medicine—Authentication of Chinese Medicinal Materials (No. 27).), the Survey and Collection of Germplasm Resources of Woody & Herbaceous Plants in Guangxi, China (GXFS–2021–34).
Data curation: YN. Funding acquisition: YN, CGX. Investigation: YN, CGX, YGW. Methodology: YN, LQL, ZYZ, YGW. Project administration: YN, BF. Supervision: XCQ, RHJ. Visualization: YN, LQL, XCQ. Writing–original draft: YN. Writing–review and editing: YN.
You Nong https://orcid.org/0000-0001-7004-0946
Li-Qun Lei https://orcid.org/0009-0009-7319-5439
Zi-Yi Zhao https://orcid.org/0000-0003-2513-0728
Gui-Yuan Wei https://orcid.org/0000-0003-0652-1213
Chuan-Gui Xu https://orcid.org/0009-0000-6263-3821
Bin Feng https://orcid.org/0000-0003-0387-3635
Xin-Cheng Qu https://orcid.org/0009-0009-9078-9976
Ri-Hong Jiang https://orcid.org/0000-0003-4908-3487
All of the data that support the findings of this study are available in the main text.