Abstract
A new endemic species, Nepenthes candalaga (Nepenthes sect. Alata) from Mt. Candalaga (eastern Mindanao, Philippines) is here described and illustrated. This new taxon resembles N. justinae but can be easily distinguished in having the lamina with 2‒3 longitudinal nerves, orbicular lid, non-bifid lid spur tip, triangular lid appendage, short banner-shaped trap wings, and absent upper pitcher rim. The species is assessed as Critically Endangered (CE) according to the IUCN criteria. This novelty is the 38th species of Nepenthes in Mindanao making the island with the highest concentration of Nepenthes species in the Philippines. This discovery increases the number of Nepenthes species in the Philippines to 61. The new taxon described faces threats of deforestation and habitat loss without legislative protection.
References
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<p>Briones, N.D. (2007) Environmental sustainability issues in Philippine agriculture. <em>Asian Journal of Agriculture and Development </em>2: 67–78.</p>
<p>Chase, M.W., Christenhusz, M.J.M., Sanders, D. & Fay, M.F. (2009) Murderous plants: Victoraian Gothic, Darwin and modern insights into vegetable carnivory. <em>Botanical Journal of the Linnean Society </em>161 (4): 329–356. https://doi.org/10.1111/j.1095-8339.2009.01014.x</p>
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<p>Cheek, M. & Jebb, M. (2013) Recircumscription of the <em>Nepenthes alata </em>group (Caryophyllales: Nepenthaceae), in the Philippines, with four new species. <em>European Journal of Taxonomy </em>69: 1–23. https://doi.org/10.5852/ejt.2013.69</p>
<p>Cheek, M., Jebb, M. & Murphy, B. (2019) A classification of functional pitcher types in <em>Nepenthes </em>(Nepenthaceae). <em>Biorxiv </em>(preprint) https://doi.org/10.1101/852137</p>
<p>Clarke, C.M. (2001) <em>Nepenthes</em> <em>of Sumatra and Peninsular Malaysia</em>. Natural History Publications (Borneo), Kota Kinabalu, x + 326 pp.</p>
<p>Clarke, S.J. & Robinson, A.S. (2018) Species of carnivorous plants. <em>In</em>: Ellison, A.M. & Adamec, L. (Eds.) <em>Carnivorous Plants: Physiology, Ecology, and Evolution</em>. Oxford University Press, Oxford, pp. 411–413.</p>
<p>Clarke, C., Bauer, U., Lee, C.C., Tuen, A.A., Rembold, K. & Moran, J.A. (2009) Tree shrew lavatories: a novel nitrogen sequestration strategy in a tropical pitcher plant. <em>Biology Letters </em>5: 632–635. https://doi.org/10.1098/rsbl.2009.0311</p>
<p>Coritico, F.P., Lagunday, N.E., Galindon, J.M., Tandang, D.N. & Amoroso, V.B. (2020) Diversity of trees and structure of forest habitat types in Mt. Tago Range, Mindanao, Philippines. <em>Philippine Journal of Systematic Biology </em>14 (3): 1–11. https://doi.org/10.26757/pjsb2020c14006</p>
<p>Danser, B.H. (1928) The Nepenthaceae of the Netherlands Indies. <em>Bulletin du Jardin de Botanique de Buitenzorg, Série III </em>9: 249–438.</p>
<p>Darwin, C. (1875) <em>Insectivorous Plants. </em>John Murray, London, 476 pp. https://doi.org/10.5962/bhl.title.99933</p>
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<p>Gaume, L., Gorb, S. & Rowe, N. (2017) Function of epidermal surfaces in the trapping efficiency of <em>Nepenthes alata </em>pitchers. <em>New Phytologist </em>156: 479–489. https://doi.org/10.1046/j.1469-8137.2002.00530.x</p>
<p>Gronemeyer, T., Suarez, W., Nuytemans, H., Calaramo, M., Wistuba, A., Mey, F.S. & Amoroso, V.B. (2016) Two new Nepenthes species from the Philippines and an emended description of Nepenthes ramos. <em>Plants</em> 5: 1–15. https://doi.org/10.3390/plants5020023</p>
<p>IUCN Standards and Petitions Committee (2022) <em>Guidelines for Using the IUCN Red List Categories and Criteria. Version 15. Prepared by the Standards and Petitions Committee.</em> Available from: https://www.iucnredlist.org/documents/RedListGuidelines.pdf (accessed 17 May 2022)</p>
<p>Jebb, M. & Cheek, M. (1997) A skeletal revision of <em>Nepenthes</em> (Nepenthaceae). <em>Blumea Journal of Plant Taxonomy and Plant Geography </em>42: 1–106.</p>
<p>Juniper, B. & Joel, D.M. (1989) <em>The Carnivorous Plants. </em>Academic Press Ltd., London, 353 pp.</p>
<p>King, C. & Cheek, M. (2020) <em>Nepenthes maximoides</em> (Nepenthaceae) a new, critically endangered (possibly extinct) species in Sect. <em>Alatae</em> from Luzon, Philippines showing striking pitcher convergence with <em>N. maxima</em> (Sect. Regiae) of Indonesia. <em>PeerJ</em> 8: e9899. https://doi.org/10.7717/peerj.9899</p>
<p>Lim, Y.S., Schöner, M.G., Kerth, G., Thornham, D.G., Scharmann, M. & Grafe, T.U. (2014) How a pitcher plant facilitates roosting of a mutualistic woolly bats. <em>Evolutionary Ecology Research </em>16: 581–591.</p>
<p>Mansell, G. & Suarez, W. (2016) <em>Nepenthes nebularum, </em>a new species from Mindanao, Philippines. <em>Carnivorous Plant Newsletter </em>45: 132–139. https://doi.org/10.55360/cpn454.gm291</p>
<p>McPherson, S.R. (2009) <em>Pitcher plants of the Old World</em>, vols. 1–2. Redfern Natural History Productions, Poole, 1399 pp.</p>
<p>Merbach, M.A., Merbach, D.J., Maschwitz, U., Booth, W.E., Fiala, B. & Zizka, G. (2002) Mass march of termites into the deadly trap. <em>Nature </em>415: 36–37. https://doi.org/10.1038/415036a</p>
<p>Moran, J.A., Clarke, C. & Gowen, B.E. (2012) The use of light in prey capture by the tropical pitcher plant <em>Nepenthes aristolochioides. Plant Signaling & Behavior </em>7: 957–960. https://doi.org/10.4161/psb.20912</p>
<p>Moya, T.B. & Malayang, B.S. (2004) Climate variability and deforestation-reforestation dynamics in the Philippines. <em>Environment, Development and Sustainability </em>6: 261–277. https://doi.org/10.1023/B:ENVI.0000003640.97351.92</p>
<p>Murphy, B., Forest, F., Barraclough, T., Rosindell, J., Bellot, S., Cowan, S., Golos, M., Jebb, M. & Cheek, M. (2020) A phylogenomic analysis of <em>Nepenthes</em> (Nepenthaceae). <em>Molecular Phylogenetics and Evolution</em> 144: 106668. https://doi.org/10.1016/j.ympev.2019.106668</p>
<p>Pavlovič, A., Slováková, Ľ. & Šantrůček, J. (2011) Nutritional benefit from leaf litter utilization in the pitcher plant <em>Nepenthes ampullaria. Plant, Cell Environ </em>34: 1865–1873. https://doi.org/10.1111/j.1365-3040.2011.02382.x</p>
<p>Posa, M.R.C. & Sodhi, N.S. (2006) Effects of anthropogenic land use on forest birds and butterflies in Subic Bay, Philippines. <em>Biological Conservation </em>129: 256–270. https://doi.org/10.1016/j.biocon.2005.10.041</p>
<p>Robinson, A.S., Fleischmann, A.S., McPherson, S.R., Heinrich, V.B., Gironella, E.P. & Peña, C.Q. (2009) A spectacular new species of <em>Nepenthes</em> L. (Nepenthaceae) pitcher plant from central Palawan, Philippines. <em>Botanical Journal of the Linnean Society</em> 159 (2): 195–202. https://doi.org/10.1111/j.1095-8339.2008.00942.x</p>
<p>Scharmann, M., Thornham, D.G., Grafe, T.U. & Federle, W. (2013) A novel type of nutritional ant-plant interaction: Ant partners of carnivorous pitcher plants prevent nutrient export by dipteran pitcher infauna. <em>PLoS One </em>8 (5): e63556. https://doi.org/10.1371/journal.pone.0063556</p>
<p>Sholz, I., Bückins, M., Dolge, L., Erlinghagen, T., Weth, A., Hischen, F., Mayer, J., Hoffmann, S., Riederer, M., Riedel, M. & Baumgartner, W. (2010) Slippery surfaces of pitcher plants: <em>Nepenthes </em>wax crystals minimize insect attachment via microscopic surface roughness. <em>Journal of Experimental Biology </em>213: 1115–1125. https://doi.org/10.1242/jeb.035618</p>
<p>Tandang, D.N., Galindon, J.M.M., Lagunday, N.E., Coritico, F.P., Amoroso, V.B. & Robinson, A.S. (2021) <em>Amylotheca cleofei sp. nov. </em>(Loranthaceae), a new species and genus record for the Philippines. <em>Phytotaxa </em>507 (1): 113–120. https://doi.org/10.11646/phytotaxa.507.1.7</p>
<p>Thorogood, C.J., Bauer, U. & Hiscock, S.J. (2018) Convergent and divergent evolution in carnivorous pitcher plant traps. <em>New Phytologist </em>217: 1035–1041. https://doi.org/10.1111/nph.14879</p>
<p>Bauer, U., Di Giusto, B., Skepper, J., Grafe, T.U. & Federle, W. (2012) With a flick of the lid: A novel trapping mechanism in <em>Nepenthes gracilis </em>pitcher plants. <em>PLoSOne </em>7: 1–7. https://doi.org/10.1371/journal.pone.0038951</p>
<p>Bazile, V. Moguédec, G. Le, Marshall, D.J. & Gaume, L. (2015) Fluid physico-chemical properties influence capture and diet in <em>Nepenthes </em>pitcher plants. <em>Annals of Botany</em> 115: 705–716. https://doi.org/10.1093/aob/mcu266</p>
<p>Blanco, F.M. (1837) <em>Nepenthes.</em> <em>Flora de Filipinas. </em>Santo Thomas [printers] por D. Candido Lopez, Manila, 619 pp.</p>
<p>Briones, N.D. (2007) Environmental sustainability issues in Philippine agriculture. <em>Asian Journal of Agriculture and Development </em>2: 67–78.</p>
<p>Chase, M.W., Christenhusz, M.J.M., Sanders, D. & Fay, M.F. (2009) Murderous plants: Victoraian Gothic, Darwin and modern insights into vegetable carnivory. <em>Botanical Journal of the Linnean Society </em>161 (4): 329–356. https://doi.org/10.1111/j.1095-8339.2009.01014.x</p>
<p>Cheek, M.R. & Jebb, M.H.P. (2001) <em>Flora Malesiana. Series I – Seed plants</em>, vol. 15: <em>Nepenthaceae</em>. Nationaal Herbarium Nederland, Leiden, iv + 164 pp.</p>
<p>Cheek, M. & Jebb, M. (2013) Recircumscription of the <em>Nepenthes alata </em>group (Caryophyllales: Nepenthaceae), in the Philippines, with four new species. <em>European Journal of Taxonomy </em>69: 1–23. https://doi.org/10.5852/ejt.2013.69</p>
<p>Cheek, M., Jebb, M. & Murphy, B. (2019) A classification of functional pitcher types in <em>Nepenthes </em>(Nepenthaceae). <em>Biorxiv </em>(preprint) https://doi.org/10.1101/852137</p>
<p>Clarke, C.M. (2001) <em>Nepenthes</em> <em>of Sumatra and Peninsular Malaysia</em>. Natural History Publications (Borneo), Kota Kinabalu, x + 326 pp.</p>
<p>Clarke, S.J. & Robinson, A.S. (2018) Species of carnivorous plants. <em>In</em>: Ellison, A.M. & Adamec, L. (Eds.) <em>Carnivorous Plants: Physiology, Ecology, and Evolution</em>. Oxford University Press, Oxford, pp. 411–413.</p>
<p>Clarke, C., Bauer, U., Lee, C.C., Tuen, A.A., Rembold, K. & Moran, J.A. (2009) Tree shrew lavatories: a novel nitrogen sequestration strategy in a tropical pitcher plant. <em>Biology Letters </em>5: 632–635. https://doi.org/10.1098/rsbl.2009.0311</p>
<p>Coritico, F.P., Lagunday, N.E., Galindon, J.M., Tandang, D.N. & Amoroso, V.B. (2020) Diversity of trees and structure of forest habitat types in Mt. Tago Range, Mindanao, Philippines. <em>Philippine Journal of Systematic Biology </em>14 (3): 1–11. https://doi.org/10.26757/pjsb2020c14006</p>
<p>Danser, B.H. (1928) The Nepenthaceae of the Netherlands Indies. <em>Bulletin du Jardin de Botanique de Buitenzorg, Série III </em>9: 249–438.</p>
<p>Darwin, C. (1875) <em>Insectivorous Plants. </em>John Murray, London, 476 pp. https://doi.org/10.5962/bhl.title.99933</p>
<p>Ellison, A.M. & Adamec, L. (2018) <em>Carnivorous Plants: Physiology, Ecology and Evolution. </em>Oxford University Press, Oxford, 509 pp. https://doi.org/10.1093/oso/9780198779841.001.0001</p>
<p>Fukushima, K., Fang, X., Alvarez-Ponce, D., Cai, H., Carretero-Paulet, L., Chen, C., Chang, T.-H., Farr, K.M., Fujita, T., Hiwatashi, Y., Hoshi, Y., Imai, T., Kasahara, M., Librado, P., Mao, L., Mori, H., Nishiyama, T., Nozawa, M., Pálfalvi, G., Pollard, S.T., Rozas, J., Sánchez-Gracia, A., Sankoff, D., Shibata, T.F., Shigenobu, S., Sumikawa, N., Uzawa, T., Xie, M., Zheng, C., Pollock, D.D., Albert, V.A., Li, S. & Hasebe, M. (2017) Genome of the pitcher plant Cephalotus reveals genetic changes associated with carnivory. <em>Nature Ecology & Evolution </em>1 (0059): 1–9. https://doi.org/10.1038/s41559-016-0059</p>
<p>Gaume, L., Gorb, S. & Rowe, N. (2017) Function of epidermal surfaces in the trapping efficiency of <em>Nepenthes alata </em>pitchers. <em>New Phytologist </em>156: 479–489. https://doi.org/10.1046/j.1469-8137.2002.00530.x</p>
<p>Gronemeyer, T., Suarez, W., Nuytemans, H., Calaramo, M., Wistuba, A., Mey, F.S. & Amoroso, V.B. (2016) Two new Nepenthes species from the Philippines and an emended description of Nepenthes ramos. <em>Plants</em> 5: 1–15. https://doi.org/10.3390/plants5020023</p>
<p>IUCN Standards and Petitions Committee (2022) <em>Guidelines for Using the IUCN Red List Categories and Criteria. Version 15. Prepared by the Standards and Petitions Committee.</em> Available from: https://www.iucnredlist.org/documents/RedListGuidelines.pdf (accessed 17 May 2022)</p>
<p>Jebb, M. & Cheek, M. (1997) A skeletal revision of <em>Nepenthes</em> (Nepenthaceae). <em>Blumea Journal of Plant Taxonomy and Plant Geography </em>42: 1–106.</p>
<p>Juniper, B. & Joel, D.M. (1989) <em>The Carnivorous Plants. </em>Academic Press Ltd., London, 353 pp.</p>
<p>King, C. & Cheek, M. (2020) <em>Nepenthes maximoides</em> (Nepenthaceae) a new, critically endangered (possibly extinct) species in Sect. <em>Alatae</em> from Luzon, Philippines showing striking pitcher convergence with <em>N. maxima</em> (Sect. Regiae) of Indonesia. <em>PeerJ</em> 8: e9899. https://doi.org/10.7717/peerj.9899</p>
<p>Lim, Y.S., Schöner, M.G., Kerth, G., Thornham, D.G., Scharmann, M. & Grafe, T.U. (2014) How a pitcher plant facilitates roosting of a mutualistic woolly bats. <em>Evolutionary Ecology Research </em>16: 581–591.</p>
<p>Mansell, G. & Suarez, W. (2016) <em>Nepenthes nebularum, </em>a new species from Mindanao, Philippines. <em>Carnivorous Plant Newsletter </em>45: 132–139. https://doi.org/10.55360/cpn454.gm291</p>
<p>McPherson, S.R. (2009) <em>Pitcher plants of the Old World</em>, vols. 1–2. Redfern Natural History Productions, Poole, 1399 pp.</p>
<p>Merbach, M.A., Merbach, D.J., Maschwitz, U., Booth, W.E., Fiala, B. & Zizka, G. (2002) Mass march of termites into the deadly trap. <em>Nature </em>415: 36–37. https://doi.org/10.1038/415036a</p>
<p>Moran, J.A., Clarke, C. & Gowen, B.E. (2012) The use of light in prey capture by the tropical pitcher plant <em>Nepenthes aristolochioides. Plant Signaling & Behavior </em>7: 957–960. https://doi.org/10.4161/psb.20912</p>
<p>Moya, T.B. & Malayang, B.S. (2004) Climate variability and deforestation-reforestation dynamics in the Philippines. <em>Environment, Development and Sustainability </em>6: 261–277. https://doi.org/10.1023/B:ENVI.0000003640.97351.92</p>
<p>Murphy, B., Forest, F., Barraclough, T., Rosindell, J., Bellot, S., Cowan, S., Golos, M., Jebb, M. & Cheek, M. (2020) A phylogenomic analysis of <em>Nepenthes</em> (Nepenthaceae). <em>Molecular Phylogenetics and Evolution</em> 144: 106668. https://doi.org/10.1016/j.ympev.2019.106668</p>
<p>Pavlovič, A., Slováková, Ľ. & Šantrůček, J. (2011) Nutritional benefit from leaf litter utilization in the pitcher plant <em>Nepenthes ampullaria. Plant, Cell Environ </em>34: 1865–1873. https://doi.org/10.1111/j.1365-3040.2011.02382.x</p>
<p>Posa, M.R.C. & Sodhi, N.S. (2006) Effects of anthropogenic land use on forest birds and butterflies in Subic Bay, Philippines. <em>Biological Conservation </em>129: 256–270. https://doi.org/10.1016/j.biocon.2005.10.041</p>
<p>Robinson, A.S., Fleischmann, A.S., McPherson, S.R., Heinrich, V.B., Gironella, E.P. & Peña, C.Q. (2009) A spectacular new species of <em>Nepenthes</em> L. (Nepenthaceae) pitcher plant from central Palawan, Philippines. <em>Botanical Journal of the Linnean Society</em> 159 (2): 195–202. https://doi.org/10.1111/j.1095-8339.2008.00942.x</p>
<p>Scharmann, M., Thornham, D.G., Grafe, T.U. & Federle, W. (2013) A novel type of nutritional ant-plant interaction: Ant partners of carnivorous pitcher plants prevent nutrient export by dipteran pitcher infauna. <em>PLoS One </em>8 (5): e63556. https://doi.org/10.1371/journal.pone.0063556</p>
<p>Sholz, I., Bückins, M., Dolge, L., Erlinghagen, T., Weth, A., Hischen, F., Mayer, J., Hoffmann, S., Riederer, M., Riedel, M. & Baumgartner, W. (2010) Slippery surfaces of pitcher plants: <em>Nepenthes </em>wax crystals minimize insect attachment via microscopic surface roughness. <em>Journal of Experimental Biology </em>213: 1115–1125. https://doi.org/10.1242/jeb.035618</p>
<p>Tandang, D.N., Galindon, J.M.M., Lagunday, N.E., Coritico, F.P., Amoroso, V.B. & Robinson, A.S. (2021) <em>Amylotheca cleofei sp. nov. </em>(Loranthaceae), a new species and genus record for the Philippines. <em>Phytotaxa </em>507 (1): 113–120. https://doi.org/10.11646/phytotaxa.507.1.7</p>
<p>Thorogood, C.J., Bauer, U. & Hiscock, S.J. (2018) Convergent and divergent evolution in carnivorous pitcher plant traps. <em>New Phytologist </em>217: 1035–1041. https://doi.org/10.1111/nph.14879</p>