Abstract
A new species of Hymenasplenium (Aspleniaceae), H. hovenkampii, from the Lesser Sunda Islands of Indonesia is described. This species was preliminarily identified as H. unilaterale, but can be easily distinguished by its bipinnatisect laminae (vs. 1-pinnate lamina) and reddish brown (vs. dark brown to black) stipes and rachises. In fact, all species known so far in the genus have simple or 1-pinnate laminae, whereas the new species is the only one in the genus with bipinnatisect laminae.
References
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Chang, Y.-F., Hori, K., Murakami, N., Cao, L.-M., Lu, S.-G. & Schneider, H. (2018) Validation of <em>Hymenasplenium laterepens</em> (Aspleniaceae): evidence from morphology and molecular analyses. <em>Phytotaxa</em> 374: 277–290. https://doi.org/10.11646/phytotaxa.374.4.1</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Copeland, E.B. (1948) A new <em>Athyrium</em> with reticulate venation. <em>American Fern Journal</em> 38: 132–134. https://doi.org/10.2307/1545168</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hance, H.F. (1883) Heptadem filicum novarum sinicarum. <em>Journal of Botany, British and Foreign</em> 21 (9): 267–270.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hayata, B. (1927) On the systematic importance of the stelar system in the Filicales, I. <em>Botanical Magazine</em> 41: 697–718. https://doi.org/10.15281/jplantres1887.41.697</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Kurata, S. & Nakaike, T. (1997) <em>Illustrations of Pteridophytes of Japan, vol. 8</em>. University of Tokyo Press, Tokyo, 419 pp.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Lin, Y.-X. & Viane, R. (2013) <em>Aspleniaceae</em>. <em>In</em>: Wu, Z.-Y., Raven, P.H. & Hong, D.-Y. (Eds.) <em>Flora of China</em>, vols. 2–3. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis, pp. 267–316.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Iwatsuki, K., Yokoyama, J. & Murakami, N. (1998) <em>Hymenasplenium inthanonense</em> (Aspleniaceae), a new fern species from Doi Inthanon, and its phylogenetic status. <em>Thai Forest Bulletin (Botany)</em> 26: 40–52.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Makino, T. (1899) Plantae Jopanenses novae vel minus cognitae. <em>Botanical Magazine, Tokyo</em> 13: 128–130. https://doi.org/10.15281/jplantres1887.13.153_128</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Mettenius, G.H. (1859) <em>Abhandlungen herausgegeben von der Senckenbergischen Naturforschenden Gesellschaft</em>. 133 pp.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Murakami, N. (1995) Systematics and evolutionary biology of the fern genus <em>Hymenasplenium </em>(Aspleniaceae). <em>Journal of Plant Research</em> 108: 257–268. https://doi.org/10.1007/BF02344351</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Murakami, N. & Moran, R.C. (1993) Monograph of the neotropical species of <em>Asplenium </em>sect. <em>Hymenasplenium </em>(Aspleniaceae).<em> Annals of the Missouri Botanical Garden</em> 80 (1): 1–38. https://doi.org/10.2307/2399820</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Murakami, N. & Schaal, B.A. (1994) Chloroplast DNA variation and the phylogeny of <em>Asplenium</em> sect. <em>Hymenasplenium</em> (Aspleniaceae) in the new world tropics. <em>Journal of Plant Research</em> 107: 245–251. https://doi.org/10.1007/BF02344251</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Qiu, Y.-L., Xu, K.-W., Ju, W.-B., Zhao, W.-L. & Zhang, L. (2022) <em>Hymenasplenium tholiformis</em> (Aspleniaceae), a new fern species from southeastern Xizang, China based on morphological and molecular evidence. <em>PhytoKeys</em> 204: 43–56. https://doi.org/10.3897/phytokeys.204.85746</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Riibe, L., Sundue, M., Sessa, E. & Testo, W. (2021) A reassessment of the little-known amazonian fern <em>diplazium praestans</em> based on molecular and morphological evidence. <em>Systematic Botany</em> 46 (2): 260–272. https://doi.org/10.1600/036364421X16231782047451</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Tagawa, M. (1938) Spicilegium pteridographiae Asiae Orientalis. <em>Acta Phytotaxonomica et Geobotanica</em> 7 (2): 72–87.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Chen, C.-W., Kamau, P., Liao, W.-B. & Zhang, L.-B. (2019a) Four new species of the fern genus <em>Hymenasplenium </em>(Aspleniaceae) from Africa and Asia. <em>Phytotaxa</em> 416: 34–42. https://doi.org/10.11646/phytotaxa.416.1.4</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Lorence, D., Wood, K.R., Liao, W.-B. & Zhang, L.-B. (2019b) A revision of the <em>Hymenasplenium unilaterale</em> subclade (Aspleniaceae; Pteridophyta) with the description of nine new species. <em>Phytotaxa</em> 419: 1–27. https://doi.org/10.11646/phytotaxa.419.1.1</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Zhou, X.-M., Yin, Q.-Y., Zhang, L., Lu, N.T., Knapp, R., Luong, T.T., He, H., Fan, Q., Zhao, W.-Y., Gao, X.-F., Liao, W.-B. & Zhang, L.-B. (2018a) A global plastid phylogeny uncovers extensive cryptic speciation in the fern genus <em>Hymenasplenium </em>(Aspleniaceae). <em>Molecular Phylogenetics and Evolution</em> 127: 203–216. https://doi.org/10.1016/j.ympev.2018.05.021</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Zhang, L., Lu, N.T., Zhou, X.-M., He, H., Luong, T.T., Knapp, R., Liao, W.-B. & Zhang, L.-B. (2018b) Nine new species of <em>Hymenasplenium </em>(Aspleniaceae) from Asia. <em>Phytotaxa</em> 358: 1–25. https://doi.org/10.11646/phytotaxa.358.1.1</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Zhou, X.-M., Zhang, L.-B. & Liao, W.-B. (2018c) <em>Hymenasplenium hastifolium </em>sp. nov. (Aspleniaceae) from a karst cave in western Guangxi, China. <em>Phytotaxa</em> 333: 281–286. https://doi.org/10.11646/phytotaxa.333.2.13</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Zhou, X.-M., Liao, W.-B. & Zhang, L.-B. (2018d) <em>Hymenasplenium perriei </em>(Aspleniaceae), a new fern species from Fiji. <em>Phytotaxa</em> 356: 177–180. https://doi.org/10.11646/phytotaxa.356.2.8</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Lu, J.-M., Zhang, X. & Zhang, L.-B. (2018e) <em>Hymenasplenium pubirhizoma </em>comb. nov. (Aspleniaceae) from China. <em>Phytotaxa</em> 351: 186–188. https://doi.org/10.11646/phytotaxa.351.2.8</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Zhang, L., Rothfels, C., Smith, A., Viane, R., Wood, K., Chen, C.-W., Knapp, R., Zhou, L., Lu, N.T., Zhou, X.-M., Wei, H.-J., Fan, Q., Chen, S.-F., Cicuzza, D., Gao, X.-F., Liao, W.-B. & Zhang, L.-B. (2020) A global plastid phylogeny of the fern genus <em>Asplenium</em> (Aspleniaceae). <em>Cladistics</em> 36: 22–71. https://doi.org/10.1111/cla.12384</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Zhang, G.-C., Hong, H.-F., Chen, G.-H., Lu, S.-G. & Chang, Y.-F. (2021) Species delimitation of <em>Hymenasplenium obliquissimum </em>group (Aspleniaceae) in southwestern China. <em>Phytotaxa</em> 480: 29–44. https://doi.org/10.11646/phytotaxa.480.1.3</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Copeland, E.B. (1948) A new <em>Athyrium</em> with reticulate venation. <em>American Fern Journal</em> 38: 132–134. https://doi.org/10.2307/1545168</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hance, H.F. (1883) Heptadem filicum novarum sinicarum. <em>Journal of Botany, British and Foreign</em> 21 (9): 267–270.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hayata, B. (1927) On the systematic importance of the stelar system in the Filicales, I. <em>Botanical Magazine</em> 41: 697–718. https://doi.org/10.15281/jplantres1887.41.697</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Kurata, S. & Nakaike, T. (1997) <em>Illustrations of Pteridophytes of Japan, vol. 8</em>. University of Tokyo Press, Tokyo, 419 pp.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Lin, Y.-X. & Viane, R. (2013) <em>Aspleniaceae</em>. <em>In</em>: Wu, Z.-Y., Raven, P.H. & Hong, D.-Y. (Eds.) <em>Flora of China</em>, vols. 2–3. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis, pp. 267–316.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Iwatsuki, K., Yokoyama, J. & Murakami, N. (1998) <em>Hymenasplenium inthanonense</em> (Aspleniaceae), a new fern species from Doi Inthanon, and its phylogenetic status. <em>Thai Forest Bulletin (Botany)</em> 26: 40–52.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Makino, T. (1899) Plantae Jopanenses novae vel minus cognitae. <em>Botanical Magazine, Tokyo</em> 13: 128–130. https://doi.org/10.15281/jplantres1887.13.153_128</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Mettenius, G.H. (1859) <em>Abhandlungen herausgegeben von der Senckenbergischen Naturforschenden Gesellschaft</em>. 133 pp.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Murakami, N. (1995) Systematics and evolutionary biology of the fern genus <em>Hymenasplenium </em>(Aspleniaceae). <em>Journal of Plant Research</em> 108: 257–268. https://doi.org/10.1007/BF02344351</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Murakami, N. & Moran, R.C. (1993) Monograph of the neotropical species of <em>Asplenium </em>sect. <em>Hymenasplenium </em>(Aspleniaceae).<em> Annals of the Missouri Botanical Garden</em> 80 (1): 1–38. https://doi.org/10.2307/2399820</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Murakami, N. & Schaal, B.A. (1994) Chloroplast DNA variation and the phylogeny of <em>Asplenium</em> sect. <em>Hymenasplenium</em> (Aspleniaceae) in the new world tropics. <em>Journal of Plant Research</em> 107: 245–251. https://doi.org/10.1007/BF02344251</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Qiu, Y.-L., Xu, K.-W., Ju, W.-B., Zhao, W.-L. & Zhang, L. (2022) <em>Hymenasplenium tholiformis</em> (Aspleniaceae), a new fern species from southeastern Xizang, China based on morphological and molecular evidence. <em>PhytoKeys</em> 204: 43–56. https://doi.org/10.3897/phytokeys.204.85746</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Riibe, L., Sundue, M., Sessa, E. & Testo, W. (2021) A reassessment of the little-known amazonian fern <em>diplazium praestans</em> based on molecular and morphological evidence. <em>Systematic Botany</em> 46 (2): 260–272. https://doi.org/10.1600/036364421X16231782047451</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Tagawa, M. (1938) Spicilegium pteridographiae Asiae Orientalis. <em>Acta Phytotaxonomica et Geobotanica</em> 7 (2): 72–87.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Chen, C.-W., Kamau, P., Liao, W.-B. & Zhang, L.-B. (2019a) Four new species of the fern genus <em>Hymenasplenium </em>(Aspleniaceae) from Africa and Asia. <em>Phytotaxa</em> 416: 34–42. https://doi.org/10.11646/phytotaxa.416.1.4</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Lorence, D., Wood, K.R., Liao, W.-B. & Zhang, L.-B. (2019b) A revision of the <em>Hymenasplenium unilaterale</em> subclade (Aspleniaceae; Pteridophyta) with the description of nine new species. <em>Phytotaxa</em> 419: 1–27. https://doi.org/10.11646/phytotaxa.419.1.1</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Zhou, X.-M., Yin, Q.-Y., Zhang, L., Lu, N.T., Knapp, R., Luong, T.T., He, H., Fan, Q., Zhao, W.-Y., Gao, X.-F., Liao, W.-B. & Zhang, L.-B. (2018a) A global plastid phylogeny uncovers extensive cryptic speciation in the fern genus <em>Hymenasplenium </em>(Aspleniaceae). <em>Molecular Phylogenetics and Evolution</em> 127: 203–216. https://doi.org/10.1016/j.ympev.2018.05.021</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Zhang, L., Lu, N.T., Zhou, X.-M., He, H., Luong, T.T., Knapp, R., Liao, W.-B. & Zhang, L.-B. (2018b) Nine new species of <em>Hymenasplenium </em>(Aspleniaceae) from Asia. <em>Phytotaxa</em> 358: 1–25. https://doi.org/10.11646/phytotaxa.358.1.1</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Zhou, X.-M., Zhang, L.-B. & Liao, W.-B. (2018c) <em>Hymenasplenium hastifolium </em>sp. nov. (Aspleniaceae) from a karst cave in western Guangxi, China. <em>Phytotaxa</em> 333: 281–286. https://doi.org/10.11646/phytotaxa.333.2.13</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Zhou, X.-M., Liao, W.-B. & Zhang, L.-B. (2018d) <em>Hymenasplenium perriei </em>(Aspleniaceae), a new fern species from Fiji. <em>Phytotaxa</em> 356: 177–180. https://doi.org/10.11646/phytotaxa.356.2.8</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Lu, J.-M., Zhang, X. & Zhang, L.-B. (2018e) <em>Hymenasplenium pubirhizoma </em>comb. nov. (Aspleniaceae) from China. <em>Phytotaxa</em> 351: 186–188. https://doi.org/10.11646/phytotaxa.351.2.8</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xu, K.-W., Zhang, L., Rothfels, C., Smith, A., Viane, R., Wood, K., Chen, C.-W., Knapp, R., Zhou, L., Lu, N.T., Zhou, X.-M., Wei, H.-J., Fan, Q., Chen, S.-F., Cicuzza, D., Gao, X.-F., Liao, W.-B. & Zhang, L.-B. (2020) A global plastid phylogeny of the fern genus <em>Asplenium</em> (Aspleniaceae). <em>Cladistics</em> 36: 22–71. https://doi.org/10.1111/cla.12384</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Zhang, G.-C., Hong, H.-F., Chen, G.-H., Lu, S.-G. & Chang, Y.-F. (2021) Species delimitation of <em>Hymenasplenium obliquissimum </em>group (Aspleniaceae) in southwestern China. <em>Phytotaxa</em> 480: 29–44. https://doi.org/10.11646/phytotaxa.480.1.3</span></span></span></p>