$¢PhytoKeys PhytoKeys 246: 189-195 (2024) DOI: 10.3897/phytokeys.246.128778 Research Article Studies on Typhonium (Araceae) of Thailand I: Typhonium vinicolor, a new species from Khon Kaen Province, Northeastern Thailand Piyaporn Saensouk', Surapon Saensouk2®, Khant Zaw Hein2*©, Thawatphong Boonma2“®, Anousone Sengthong°, Sarayut Rakarcha® 1 Diversity of Family Zingiberaceae and Vascular Plant for Its Applications Research Unit, Department of Biology, Faculty of Science, Mahasarakham University, Kantarawichai District, Maha Sarakham 44150, Thailand 2 Diversity of Family Zingiberaceae and Vascular Plant for Its Applications Research Unit, Walai Rukhavej Botanical Research Institute, Mahasarakham University, Kantarawichai District, Maha Sarakham 44150, Thailand nO on Se WwW Ta Yote Tan Street, Monywa, 02301, Sagaing Region, Myanmar Brio Botanical Research Garden, 53 M. 5 Phikun-ok, Ban Na District, Nakhon Nayok 26110, Thailand Faculty of Forest Science, National University of Laos, Vientiane Capital, 7322, Laos Queen Sirikit Botanic Garden, The Botanical Garden Organization, Chiang Mai 50180, Thailand Corresponding author: Surapon Saensouk (Surapon.s@msu.ac.th) OPEN Qaceess Academic editor: Duilio lamonico Received: 1 June 2024 Accepted: 18 August 2024 Published: 3 September 2024 Citation: Saensouk P. Saensouk S, Hein KZ, Boonma T, Sengthong A, Rakarcha S (2024) Studies on Typhonium (Araceae) of Thailand |: Typhonium vinicolor, a new species from Khon Kaen Province, Northeastern Thailand. PhytoKeys 246: 189-195. https://doi. org/10.3897/phytokeys.246.128778 Copyright: © Piyaporn Saensouk et al. This is an open access article distributed under terms of the Creative Commons Attribution License (Attribution 4.0 International - CC BY 4.0). Abstract Typhonium vinicolor from Khon Kaen Province (Northeastern Thailand), is described and illustrated as a species new to science. Color plates, phenology, distribution, discussion of similar taxa, and conservation status assessment are provided. Key words: Areae, Aroideae, Indochina, Northeastern Thailand, plant taxonomy Introduction Typhonium Schott (1829) (Araceae Juss.) is a genus of tuberous (sometimes rhizomatous or stoloniferous), terrestrial, and seasonally dormant herbs that inhabit forest floors, rocky areas, wet sites, stream sides, and grassy places in tropical and subtropical humid and seasonal forests, as well as in agricultural land (Mayo et al. 1997; Low et al. 2020). Hay et al. (2022) transferred most of the Australian Typhonium species to Lazarum A.Hay, so, according to these authors Typhonium (sensu stricto) would refer to species mainly distributed in Indochina (see e.g., Low et al. 2020; Hay and Hein 2022). Among the genera of tribe Areae, Typhonium s.str. is the largest one, with more than 70 species (100 based on Boyce and Croat 2011; 72 in POWO 2024). The highest species diversity of Typhonium is found in Thailand, with 32 species, 24 of which are endemic (Boyce et al. 2012). Later than Boyce et al. (2012), six new species have been described from Thailand (Galloway 2012, 2015; Hetterscheid 2013; Sookchaloem and Maneeanakekul 2018), increasing the total number of spe- cies in the country to 38. However, the current number of species occurring in Thailand is undoubtedly much higher (Boyce et al. 2012). 189 Piyaporn Saensouk et al.: Typhonium vinosum, a new species from Khon Kaen Province, Northeastern Thailand During our botanical survey in Khon Kaen Province (Northeastern Thailand), an unknown species of Typhonium was collected by the second author (SS). After meticulously examining its morphology and comparing it with proto- logues and relevant literature, as well as with digitized type specimens from Thailand and neighboring countries, it became apparent that the collected specimen does not match any other known Typhonium species. Thus, we con- sider it to represent a taxonomic novelty, which is described and illustrated in the present paper. Materials and methods The measurements and descriptions were based on freshly collected and/or al- cohol-preserved material, processed according to the methods established by Davies et al. (2023). The species description follows Hay and Hein (2022), while Araceae morphological terminology follows Mayo et al. (1997) implemented by the descriptive terminology of Beentje (2016). Relevant type specimens of Typhonium species from Thailand and neighboring countries were examined in different herbaria (A, AAU, B, BK, BKF, C, CAL, CMU, E, HITBC, K, KKU, KUN, L, M, MO, P, PE, QBG, SING, and WAG; acronyms follow Thiers 2024) through high-resolution images from https://plants.jstor.org/ and Global Biodiversity In- formation Facility (GBIF) accessed from https://www.gbif.org. An assessment of conservation status was carried out following IUCN (2024), based on our current knowledge and the respective terminology on categories, criteria, and subcriteria. The photographs in the plate were taken with an iPhone 13 (iOS version 17.5.1, 2021, Apple Inc., Cupertino, CA, USA). The figure in this study was created using Pixelmator Pro (Version 3.6.5, Archipelago, 2023, Pixelma- tor Team, Vilnius, Lithuania) on a MacBook Pro (13-inch, M1, 2020, Apple Inc., Cupertino, CA, USA). Taxonomic treatment Typhonium vinicolor P. Saensouk, K.Z.Hein & Saensouk, sp. nov. urn:lsid:ipni.org:inames:77347851-1 Fig. 1 Type. THAILAND * Northeastern — Khon Kaen Province, 13 May 2023, Surapon Ara001 (holotype KKU!; isotypes FOF!, MSU). Diagnosis. Typhonium vinicolor is easily distinguishable from the other Ty- phonium species by having narrowly elliptic to elliptic-lanceolate leaf blades with a reddish-purple abaxial surface. An only exception is T. laoticum Gagnep. (Gagnepain 1942), which shows similar leaf blades. However, T. vinicolor dif- fers from T. laoticum by its reddish-purple abaxial surface of leaf blades (vs. pale green), white or pale green spathe with dark purple mottling externally (vs. pink spathe with brown mottling externally), pistillate zone with 5-6 pistil rows (vs. 2-3 pistil rows), and staminodes more or less loosely arranged in 4—5 spi- rals (vs. staminodes densely arranged in 2-3 spirals). Description. Small, deciduous, herbs, to 15 cm tall. Stem hypogeal, subglo- bose or depressed globose tuber, 1.2-—1.5 cm in diameter, externally pale brown, internally white. Roots filiform, 0.6—1.0 mm in diameter, white. Leaves 1-2(-3) PhytoKeys 246: 189-195 (2024), DOI: 10.3897/phytokeys.246.128778 190 Piyaporn Saensouk et al.: Typhonium vinosum, a new species from Khon Kaen Province, Northeastern Thailand together; petioles 6.5—8.5 cm long, ca. 0.2 cm in diameter, erect, slender, terete, glabrous, basal subterranean portion white, upper aerial portion pale green with numerous longitudinal dark purple striations and spots; petiolar sheath 2.5-3.0 cm long, ca. 1/3 of petiole length; leaf blade 8.0-13.0 x 1.8-4.2 cm, narrowly elliptic to elliptic-lanceolate, or elliptic-oblanceolate, chartaceous, adaxially me- dium green, abaxially reddish-purple, glabrous on both sides, base cuneate or obtuse, margin entire, apex acute and mucronate, mucro ca. 1 mm long; midrib adaxially impressed, abaxially raised, rounded, 1.5-1.8 mm wide at the base, ca. 1.0 mm wide at center, then narrowing towards blade apex; primary lateral veins 5-7 per side, adaxially impressed, abaxially raised, diverging from the midrib at 15-30°, anastomosing at 0.5-1.5 mm from margin into an intram- arginal collective vein; higher order venation reticulate. Inflorescence solitary, subtended by a cataphyll; cataphyll up to 3.0 cm long, linear-lanceolate, mem- branous, semi-hyaline, greenish white or white, later withering brown; peduncle 2.8-3.2 cm long, ca. 0.2 cm in diameter, almost entirely subterranean, white, terete, glabrous; spathe 8.5—9.5 cm long, strongly differentiated into a spathe tube and a spathe limb by a constriction; spathe tube ca. 1.2 cm long, 0.6-0.7 cm in diameter, convolute, ellipsoid-ovoid, externally white or greenish white with a dense dark purple mottling, internally greenish white; spathe limb 7.3- 8.3 cm long, 0.6-0.7 cm in diameter at base, linear-lanceolate, tapering towards apex, externally green or yellowish-green with dark purple mottling, internally pale yellowish green, basal part of limb shortly convolute and erect, upper part reflexed and then strongly coiled at anthesis, apex narrowly acute. Spadix ses- sile, 8.0-9.0 cm long, nearly as long as or shorter than spathe; pistillate zone ca. 2mm long, ca. 3 mm in diameter at the base, shortly conical, with 5-6 rows of congested pistils; ovary ca. 0.7 mm high, ca. 0.5 mm in diameter, obovoid, white, unilocular with one basal ovule held obliquely on a funicle, on a basal placenta; style very short, ca. 0.1 mm high, ca. 2.5 mm in diameter; stigma ca. 0.3 mm in diameter, discoid, red, papillate; sterile interstice between pistillate and staminate zones 0.8-1.0 cm long, ca. 0.1 cm in diameter, upper part na- ked, terete, glabrous, glossy white, lower ca. 0.2 cm covered with 4-5 spirals of staminodes; staminodes 1.2-1.5 mm long, 0.5-0.7 mm in diameter at wid- est point, clavate-fusiform, shortly beaked with acute apex, free, slightly distant from each other, perpendicular to the spadix axis or slightly curved downwards, glabrous, yellow; staminate zone 0.7-1.0 cm long, ca. 0.3 cm in diameter, cy- lindric; stamens congested, not ostensibly arranged into staminate flowers, irregularly 4-lobed, 0.6—0.7 mm in diameter, pink or yellow, dehiscing by an api- cal pore; appendix sessile, 6.2—7.0 cm long, 1.5-2.0 mm in diameter, narrowly elongate-conical, tapering towards apex, erect or weakly arching, glabrous, ivo- ry-colored, base slightly attenuate, apex acute. Infructescence not seen. Etymology. The specific epithet is derived from the Latin “vinicolor” (wine-co- loured), referring to the reddish-purple abaxial surface of the leaves. Proposed vernacular name. Uttapit-See-Wine. Phenology. Flowering time in May. Distribution and habitat. The newly discovered species is found exclusively at its type locality in Khon Kaen Province (Northeastern Thailand). It thrives in shaded to semi-shaded areas of tropical deciduous forests at elevations rang- ing from 200 to 250 m a.s.l. The species shows optimal growth in sandy loam soil mixed with rocks. PhytoKeys 246: 189-195 (2024), DOI: 10.3897/phytokeys.246.128778 191 Piyaporn Saensouk et al.: Typhonium vinosum, a new species from Khon Kaen Province, Northeastern Thailand Figure 1. Typhonium vinicolor A plant in habitat B excavated flowering plants C leaf blade (left showing adaxial surface, right showing abaxial surface) D inflorescence at pistillate anthesis, nearside spathe artificially removed E spadix at pis- tillate anthesis, nearside spathe artificially removed. Photos by: Surapon Saensouk and Thawatphong Boonma. Conservation status. This new species is known exclusively from its type locality, and no sufficient information there is regarding potential threats to its habitat. In accordance with the Red List criteria of the IUCN Standards and Petitions Subcommittee (2024), we propose classifying this species as ‘Data PhytoKeys 246: 189-195 (2024), DOI: 10.3897/phytokeys.246.128778 192 Piyaporn Saensouk et al.: Typhonium vinosum, a new species from Khon Kaen Province, Northeastern Thailand Deficient’ (DD). Further research is necessary, as there is inadequate informa- tion to assess the conservation status of this species. Currently, data is limited regarding its distribution, with no details on population size, trends, or potential threats to its habitat. Taxonomic notes. Based on overall morphology, this new species is also similar to Typhonium griseum Hett. & Sookch. (Hetterscheid et al. 2001), which is a sister species of T. laoticum (Low et al. 2020). But T. vinicolor is strikingly different from T. griseum in having the leaf blade base cuneate or obtuse (vs. with rounded posterior lobes), spadix nearly as long as, or shorter than, spathe (vs. longer than spathe), clavate-fusiform and yellow staminodes (vs. narrowly fusiform, sickle-shaped, white staminodes), longer staminate zone (ca. 1 cm vs. ca. 0.5 cm long), and erect or weakly arching, ivory-colored appendix (vs. strongly arching, pale brown appendix). Regarding spathe and spadix structures, the new species also resembles Typhonium huense V.D.Nguyen & Croat (Nguyen and Croat 1997), T. lineare Hett. & V.D.Nguyen (Hetterscheid and Nguyen 2001) and T. stigmatilobatum V.D.Nguyen (Nguyen 2008) from Vietnam. However, the latter three species dif- fer from T. vinicolor by having horizontally flexed spathe limb at anthesis (vs. only the upper part of spathe limb reflexed and then strongly coiled at anthe- sis in T. vinicolor) and strongly arching, dark brown or violet, stipitate appendix (vs. erect or weakly arching, ivory, sessile appendix in T. vinicolor). A more de- tailed comparison between T. vinico/or and its morphologically allied species is presented in Table 1. Additional specimens examined (paratypes). THAILAND * Northeastern — Khon Kaen Province, 18 May 2024, Saensouk, Boonma & Sengthong, SS 24518 (FOF'). Table 1. Morphological comparison of Typhonium vinicolor and its allied species, T. griseum (Hetterscheid et al. 2001), T. huense (Nguyen and Croat 1997), T. laoticum (Gagnepain 1942; Boyce et al. 2012), T. lineare (Hetterscheid and Nguyen 2001) and T. stigmatilobatum (Nguyen 2008). T. griseum T. huense T. laoticum T. lineare T. stigmatilobatum T. vinicolor Leaf blade orbicular, triangular-cordate to | lanceolate or elliptic- pedatisect with deeply trilobed or narrowly elliptic to triangular cordate deeply trilobed oblong linear or linear- pedatisect with ovate elliptic-lanceolate or narrowly ovate lanceolate lobes _| to oblong-ovate lobes Spathe tube ca. 1 cm long, ca. 1.5 cm long, 1.3-1.5 cm long, up to 1.8 cm long, ca. 1.3 cm long, ca. 1.2 cm long, externally dirty | externally pale green | externally pink with | externally whitish- | externally pale green externally white or white with with purplish violet | brown striations and | gray with blackish- or dull white with greenish-white with brownish-red spots spots spots gray striations and | black or brown spots | a dense dark purple spots mottling Spathe limb ca. 10 ca. 6 4—5 times longer 7-8 times longer 10-12 times longer 6-7 times longer times longer times longer than spathe tube than spathe tube than spathe tube than spathe tube than spathe tube than spathe tube Spadix longer than spathe, | as long as or slightly shorter than the as long as or slightly | as long as spathe, up | nearly as long as or ca. 13 cm long longer than spathe, spathe, ca. 7 cm shorter than spathe, to 17 cm long shorter than spathe, up to 11 cm long long up to 17 cm long 8.0-9.0 cm long Staminodes narrowly fusiform, variously clavate, subulate or fusiform, fusiform, clavate-fusiform, fusiform, sickle- directed, yellowish perpendicular to variously directed, perpendicular to the | perpendicular to the shaped, curved white the spadix axis or white or yellow spadix axis or slightly | spadix axis or slightly downwards, white curved upwards, curved downwards, curved downwards, white dull white yellow Appendix sessile, ca. 12 stipitate, ca. 9 sessile, ca. 5cm stipitate, ca. 15 sessile, 14-15 cm sessile, 6.2-7.0 cm cm long, strongly arching, pale brown cm long, strongly arching, brown or violet long, erect, pale brown PhytoKeys 246: 189-195 (2024), DOI: 10.3897/phytokeys.246.128778 cm long, strongly arching, brown or golden yellow long, strongly arching, dark brown long, erect or weakly arching, ivory-colored 193 Piyaporn Saensouk et al.: Typhonium vinosum, a new species from Khon Kaen Province, Northeastern Thailand Acknowledgments The third author (KZH) is grateful to Alistair Hay for his expert advice and guid- ance in aroids research. Additional information Conflict of interest The authors have declared that no competing interests exist. Ethical statement No ethical statement was reported. Funding This research was financially supported by Mahasarakham University. Author contributions Conceptualization PS, SS, and KZH; Data curation PS, SS, KZH, TB; Formal analysis PS, SS, KZH; Funding acquisition SS; Investigation SS, TB, and AS; Methodology PS, SS, KZH, and TB; Project administration PS and SS; Resources SS, TB, and AS; Supervision SS; Validation PS, SS, KZH, and TB; VisualizationPS, SS, KZH, and TB; Writing - original draft KZH and TB; Writing - reviewing and editing PS, SS, KZH, TB, AS, and SR. Author ORCIDs Surapon Saensouk © https://orcid.org/0000-0002-9178-188X Khant Zaw Hein ® https://orcid.org/0000-0002-8735-9264 Thawatphong Boonma ® https://orcid.org/0000-0003-2324-4967 Data availability All of the data that support the findings of this study are available in the main text. References Beentje H (2016) The Kew plant glossary: an illustrated dictionary of plant terms. 2"4 edn. Royal Botanic Garden, Kew, 184 pp. Boyce PC, Croat TB (2011) The Uberlist of Araceae, totals for published and estimated number of species in aroid genera. http://www.aroid.org/genera/140601 uberlist.pdf [Retrieved 25 May 2024] Boyce PC, Sookchaloem D, Hetterscheid WLA, Gusman G, Jacobsen N, Idei T, Nguyen VD (2012) Araceae. Flora of Thailand 11: 101-321. Davies NMJ, Drikell C, Utteridge TMA (2023) The Herbarium Handbook. Royal Botanic Gardens, Kew, 290 pp. Gagnepain F (1942) Aracées. In: Lecomte H (Ed.) Flore générale de I'Indo-Chine 6: 1075-1196. Paris. Galloway A (2012) New Araceae species from Laos and Thailand. Aroideana 35: 51-64. Galloway A (2015) Two new Typhonium species from Laos and Thailand. Aroideana 38: 8-12. Hay A, Hein KZ (2022) A new combination and new synonyms for Sauromatum Schott (Araceae—Areae) of northeastern India and Bangladesh. Aroideana 45(3): 148-159. PhytoKeys 246: 189-195 (2024), DOI: 10.3897/phytokeys.246.128778 194 Piyaporn Saensouk et al.: Typhonium vinosum, a new species from Khon Kaen Province, Northeastern Thailand Hay A, Barrett MD, Hetterscheid WLA (2022) New combinations in resurrected Lazarum A.Hay (Araceae—Areae). Aroideana 45(3): 133-137. Hetterscheid WLA (2013) New Typhonium species from Asia. Aroideana 36: 93-97. Hetterscheid WLA, Nguyen VD (2001) Three new species of Typhonium (Araceae) from Vietnam. Aroideana 24: 24-29. Hetterscheid W, Sookchaloem D, Murata J (2001) Typhonium (Araceae) of Thailand: New species and a revised key. Aroideana 24: 30-55. IUCN (2024) The Guidelines for Using the IUCN Red List Categories and Criteria, Ver- sion 16 (March 2024). https://nc.iucnredlist.org/redlist/content/attachment_files/ RedListGuidelines.pdf [Retrieved 28 May 2024] Low SL, Yu CC, Ooi IH, Eiadthong W, Galloway A, Zhou ZK, Xing YW (2020) Extensive Miocene speciation in and out of Indochina: The biogeographic history of Typhonium sensu stricto (Araceae) and its implication for the assembly of Indochina flora. Jour- nal of Systematics and Evolution 59(3): 419-428. https://doi.org/10.1111/jse.12689 Mayo SJ, Bogner J, Boyce PC (1997) The genera of Araceae. Kew: Royal Botanic Gar- dens, 370 pp. https://doi.org/10.1007/978-3-662-03531-3_7 Nguyen VD (2008) Typhonium stigmatilobatum (Araceae tribe Areae), a new species from Vietnam. Kew Bulletin 63(3): 491-493. https://doi.org/10.1007/s12225-008- 9044-8 Nguyen VD, Croat TB (1997) A new species of Typhonium (Araceae) from Vietnam. Ar- oideana 20: 48-52. https://doi.org/10.2307/4110401 POWO (2024) Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. http://www.plantsoftheworldonline.org/ [Retrieved 25 May 2024] Schott HW (1829) Fiir Liebhaber der Botanik. Wiener Zeitschriftfiir Kunst, Litteratur. The- ater und Mode 3: 732. Sookchaloem D, Maneeanakekul S (2018) Typhonium muaklekense sp. nov. (Araceae) from Thailand. Nordic Journal of Botany 36(5): e01619. https://doi.org/10.1111/ njb.01619 Thiers BM (2024) Index Herbariorum: a global directory of public herbaria and associat- ed staff. New York Botanical Garden's Virtual Herbarium. http://sweetgum.nybg.org/ science/ih/ [Accessed 11 August 2024] PhytoKeys 246: 189-195 (2024), DOI: 10.3897/phytokeys.246.128778 195