$¢PhytoKeys PhytoKeys 252: 1-7 (2025) DOI: 10.3897/phytokeys.252.134081 Research Article Typhonium morangense (Araceae), a new species from the tropical forest of Eastern Nepal Rijan Ojha’?®, Sudeep Rai?®, Harald Schneider'® 1 Center for Integrative Conservation and Yunnan Key Laboratory for Conservation of Tropical Rainforests and Asian Elephants, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China 2 University of Chinese Academy of Sciences, Beijing, 100049, China 3 Biodiversity Research and Conservation Society, Kathmandu, Nepal Corresponding author: Rijan Ojha (rijan@xtbg.ac.cn) OPEN Qaceess Academic editor: Duilio lamonico Received: 10 August 2024 Accepted: 7 December 2024 Published: 30 January 2025 Citation: Ojha R, Rai S, Schneider H (2025) Typhonium morangense (Araceae), a new species from the tropical forest of Eastern Nepal. PhytoKeys 252: 1-7. https://doi. org/10.3897/phytokeys.252.134081 Copyright: © Rijan Ojha 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 A new species of the aroid genus Typhonium Schott has been discovered in East- ern Nepal. This species, named Typhonium morangense R.Ojha & S.Rai, is described based on comparative morphological examinations with closely related species from the Indian subcontinent. The new species is currently known only from Pathari Shan- ishchare Municipality in the Morang district of Eastern Nepal. It is the second species of Typhonium observed in Nepal, and the only one endemic to the country. A detailed description, color plate, geographic distribution, phenology, and morphological com- parison of the new species with morphologically close species are provided. Given its restricted range and the low number of individuals observed in the wild, this species requires special attention from conservation biologists working in Eastern Nepal. Key words: Bulbils, Koshi Province, Morang, Typhonium inopinatum Introduction The moderately species-rich aroid genus Typhonium Schott is expected to com- prise around 100 species (Hetterscheid and Sookchaloem 2012), of which 72 species currently have accepted names, according to Plants of the World Online (POWO 2024). Phylogenetic studies have confirmed the placement of this genus in the tribe Areae, belonging to the subfamily Aroideae (Zhao et al. 2023). The genus is widely distributed across tropical to subtropical Asia, extending from the central Himalayas to New Guinea and Australia. More than half of the currently accepted Typhonium species are found in the Indochina region (Pham et al. 2023). Due to the high diversity and endemism of the genus in the Indochina region, it has long been considered the center of origin for the genus Typhonium. This is further sup- ported by a recent biogeographic reconstruction study by Low et al. (2020), which suggests a middle to early Miocene origin (approximately 17.24 Ma) of the genus in the Indochina region. Within this region, the highest diversity (33 species) and en- demism (23 species) are found in Thailand (Hetterscheid and Sookchaloem 2012; Sookchaloem and Maneeanakekul 2018). This center of biodiversity likely harbors several undiscovered species, as indicated by the recent discovery of Typhonium hangiae V.D.Nguyen, D.D.Nguyen & V.C.Nguyen and Typhonium obtusum Luu, X.B. Rijan Ojha et al.: Anew species of Typhonium from Eastern Nepal Nguyen-Le & H.C. Nguyen in Vietnam (Pham et al. 2023; Luu et al. 2024). Given the known distribution of the genus, only a few species are found in the Himalayas. For example, only one species, Typhonium trilobatum (L.) Schott, has been reported in Nepal (Shrestha et al. 2022). As the northwestern distribution border of the genus, Nepal stands out as an important area for studying the diversity of Typhonium. As part of our ongoing efforts to document the diversity of Araceae in Nepal, field surveys were conducted in the tropical forests of Eastern Nepal (Rajapaksha et al. 2023; Rai et al. 2024). In early 2024, a population of small aroids with 2-5 hastate to trilobate leaves and a pinkish-brown inflorescence was encountered. At first glance, these plants resembled the widespread T. roxburghii Schott or the more narrowly distributed T. inopinatum Prain, known to occur in India, Myanmar, and Thailand, due to the shape of their leaves, the inner color of the spathe, and the appearance of the spadix. However, detailed morphological examinations revealed these plants to be distinct from these two species and any previously described species. Thus, we introduce these plants as a new species endemic to Eastern Nepal. Materials and methods To provide detailed information about the plant, we observed several individuals across different patchy stands. Mature individuals were collected to be deposited as herbarium specimens, while some inflorescences were preserved as pickled samples for further study. The morphometric study included a total of 20 individ- uals. Measurements of various parts of the living plants were taken in the field and photographs were captured using a Nikon Coolpix P900 camera. Micro-mor- phological measurements of flower parts of the specimens were examined using a dissection microscope. The images of these structures were taken using a mo- bile phone camera. Relevant literature was consulted to compare the morphology with closely related species and other species of the genus found in neighboring countries (Murata et al. 2010; Hetterscheid and Sookchaloem 2012; Venu and Rao 2014; Nirola and Das 2014; Manudev and Nampy 2022; Pham et al. 2023). Im- ages of Typhonium specimens available in virtual herbaria and databases, includ- ing KATH (http://plantdatabase.kath.gov.np), CAL, ARUN, BM, P PE (http://www. cvh.ac.cn), US, and others accessible through https://www.gbif.org and https:// plants.jstor.org, were also examined (herbarium acronyms follow Thiers 2024). In addition to studying images of type specimens and protologs, the morphological characterization of putatively related species was based on descriptions provided by Li and Hetterscheid (2010) for T. roxburghii; King and Prain (1898), Venu and Rao (2014), and Luu et al. (2024) for T. inopinatum; Manudev and Nampy (2022) for T. bulbiferum Dalzell; and Murata et al. (2010) for T. cordifolium S.Y.Hu. Taxonomic treatment Typhonium morangense R.Ojha & S.Rai, sp. nov. urn:lsid:ipni.org:names:77355953-1 Fig. 1 Type. NEPAL, Koshi Province, Morang District, Pathari Shanishchare Munici- pality; 26°39'59"N, 87°33'29"E; ca.150 m; 2024.06.03; Sudeep Rai MP077 [holo- type KATH! isotypes KATH! [MP012], TUCH!, TURH!]. PhytoKeys 252: 1-7 (2025), DOI: 10.3897/phytokeys.252.134081 D Rijan Ojha et al.: Anew species of Typhonium from Eastern Nepal Diagnosis. Typhonium morangense is morphologically closely related to T. inopinatum but it differs significantly from the latter species in having (1) smaller habit, 10-24 cm height (vs. 10-45 cm in T. inopinatum); (2) globose bulbils on top of petiole and leaves (vs. bulbils absent); (3) a sessile appendix (vs. subsessile); (4) thick, sickle-shaped staminodes (vs. filiform); (5) stami- nodes half curved downwards (vs. horizontally spread or, slightly curved); (6) ovary white (vs. yellowish) and (7) stigma pink (vs. yellow). Description. Seasonally dormant small herb, 10-24 cm tall; Tuber 0.8-2 cm long, 1-2 cm diameter, upright, sub-globose to sub-cylindrical with many filiform roots, without rhizomatous offsets. Leaves 2-5 together; petiole 10-23 cm long, light brown, grayish brown at base to light green at apex, globose black bulbil on the top of petiole. Leaf blade entire, hastate or shallowly or deeply tri-lobed or trifoliolate, glabrous, adaxially green, abaxially lighter green, 5-11 cm long, 2-7 cm wide when hastate, 10-12 cm when deeply trilobed, globose black bulbil on the basal margin of the leaf. Inflorescence solitary, usually 1-2 together, short- er than petiole; peduncle subterranean, white, 1.2—3.8 cm long; spathe 5.5-12 cm long, tube and limb separated by a constriction, grayish pink outside, inside dark reddish purple color; spathe tube ovoid to cylindric, 1-1.5 cm long, 1-1.7 cm di- ameter, outside grayish pink, inside reddish purple; spathe limb narrowly triangu- lar, 4.5-10.5 cm long, 1-3 cm wide, smoothly tapering from below middle, apex acute; spadix 6.5—9.5 cm long, as long as spathe or slightly longer, sessile; female zone conical, 2-6 mm long, 4-5 mm diameter at the base, slightly pink, ovary uni- locular, white with one dark yellow basal ovule, style absent, stigma sessile, disc shape with dark pink over the periphery; staminodes arranged in three whorls, free at the base, thick sickle-shaped, half-length curved downwards, yellow, glabrous, cover 1/3" of the female zone; male zone 5-8 mm long, 3-5 mm diameter, cylin- drical, stamens congested, thecae two, irregular, coral pink to sandy brown color with apical short slits or pores; appendix usually sessile, 2.7-7.7 cm long, narrow- ly elongated conical, dark reddish purple, base obliquely truncate, top acute, inside semisolid. Fruits ovoid to capsule-shaped, 0.2—0.3 cm diameter, 0.3-0.4 cm long, slightly light green at initial stages while turning white after maturity. Phenology. Flowering in May to June, fruiting July to August. Etymology. The specific epithet is based on the locality of its discovery, the Morang district of Eastern Nepal. Distribution and habitat. The new species is known from Pathari Shanish- chare municipality, Morang district, growing under the canopy of dense Shorea robusta Gaertn. forest at ca. 150 m asl. This species prefers moist shady floors under the dense canopy of forest. Uses. No reports for utilization by the local human population are known. Conservation status. The new species has been recorded only from its type locality, where it forms patchy stands of approximately 150 individuals. However, it is highly likely to be present in similar nearby habitats. Together with the type locality, these undiscovered sites are expected to contain several hundreds of individuals. Until further investigation, the species is provisionally designated as “Data Deficient” (DD) following the IUCN standards (IUCN 2024). Conservation biologists active in Eastern Nepal may want to consider this spe- cies as requiring attention, as it is a local endemic known only from this region. Taxonomicnotes. Thehastateleaf shape, smallinflorescence size, and presence of a few staminodes are shared characteristics between Typhonium inopinatum PhytoKeys 252: 1-7 (2025), DOI: 10.3897/phytokeys.252.134081 3 Rijan Ojha et al.: Anew species of Typhonium from Eastern Nepal Figure 1. Typhonium morangense sp. nov. A whole plant B different forms of leaf blade C bulbils D inflorescence E male zone F female zone and staminodes G longitudinal section of appendix H fruits. and T. morangense. However, apart from key differences presented in diagno- sis, T. morangense can be distinguished from T. inopinatum by the color of the spathe (grayish pink outside and reddish purple inside vs. basally brownish, api- cally green), the color of appendix (reddish purple vs. yellow, yellowish-brown), PhytoKeys 252: 1-7 (2025), DOI: 10.3897/phytokeys.252.134081 4 Rijan Ojha et al.: Anew species of Typhonium from Eastern Nepal the length of the spadix (as long as or slightly longer than the spathe vs. shorter than the spathe), the female flowers (without style vs. with style). 7; morangense also shares several similarities with T. roxburghii, in the habit and the color of spathe. However, T. morangense differs from T. roxburghii in several characteris- tics: the size of the inflorescence (spathe limb 4.5-10.5 x 1-3 cm vs. 13-15 x ~5 cm; appendix 2.7—7.7 cm vs. 12-15 cm), the arrangement of the staminodes (arranged in three whorls vs. more than three whorls; half-length curved down- ward vs. only the tips pointing downward), the appendix (sessile vs. stipitate), the shape of the ovule (ellipsoid vs. ovoid), and the color of the stigma (pink vs. purple). Although T. inopinatum and T. roxburghii share several similar characters with T. morangense, neither has bulbils. Bulbils have also been reported in the Indian endemic T. bulbiferum and T. cor- difolium distributed in Myanmar, Thailand, Vietnam, and Cambodia (Nguyen et al. 2022). These two species differ from T. morangense by having triangular to sagittate or cordate leaves in T. bulbiferum and ovate to elliptic leaves in T. cordifolium (vs. hastate, trilobed, or trifoliolate leaves in T. morangense). Additionally, T. bulbiferum has a linear-lanceolate, pale rose spathe with an acuminate apex, and T. cordifoli- um has a narrowly triangular-ovate, dark reddish-purple to purplish spathe with an acuminate and apically curled apex (vs. narrowly triangular, grayish-pink spathe with a dark reddish-purple interior and an acute apex in T. morangense). It is noted that a plant from India with globose bulbils on the lower leaf mar- gin and the petiole apex, which was identified as T. roxburghii by Nirola and Das (2014), was recently confirmed to be a misidentification (Manudev and Nampy 2022). This indicates uncertainty in identification due to the presence of bulbils. A comprehensive morphological comparison of the new species with these related species is presented in Table 1. Table 1. Morphological differences between Typhonium morangense and closely related species. Height Leaf blade Bulbils Spadix Appendix Spathe tube Spathe limb Stamens Staminod T. morangense 10-24 cm hastate or tri-lobed or trifoliolate, entire, 5-11 x 2-12 cm globose, black on the top of the petiole and leaves base 6.5-9.5 cm long, sessile, as long as spathe limb 2.7-7.7 cm long, dark- reddish purple, usually sessile, base obliquely truncate, apex acute ovoid to cylindrical, 1-1.5 cm long, 1-1.7 cm in diameter, outside grayish pink, inside reddish purple narrowly triangular, 4.5- 10.5 x 1-3 cm, grayish pink outside, dark reddish purple inside, acute apex coral pink to sandy brown thick sickle-shaped, arranged in three whorls, half-length curved downwards, acute tip T. bulbiferum T. cordifolium 15-30 cm triangular hastate, sagittate or cordate, mid lobe 5-8 x 3-6 cm globose to linear bulbils slender, as long as spathe 7-14.cm long, pale yellow to cream, stipitate, rounded at the base oblong, 1-2 cm long. linear-lanceolate, 7-16 x 2-4 cm, hyaline or pale rose, acuminate at apex acinaciformis, curved, uniseriate PhytoKeys 252: 1-7 (2025), DOI: 10.3897/phytokeys.252.134081 narrowly ovate-elliptic to elliptic, 4-25 x 1.5-4 cm present on the apex of the leaf as long as spathe 3.6-7.7 cm long, brick orange-colored, base not truncate 1.2 x 1 cmlong narrowly triangular-ovate, 5-9 x 3 cm, dark reddish purple to purplish brown, apex acuminate, upright or recurved, and curled apically creamy white cylindrical, spreading, obtuse tip T. inopinatum 10-45 cm ovate to triangular or hastate, entire, 8 x 2.cm long absent 4.3-9 cm long, shorter than spathe limb 4-6 cm long, yellow, yellowish-brown, subsessile, base truncate ovoid, 2 cm cm long, 1.5 cm wide, greenish inside and outside narrowly ovate to lanceolate, 9-10 x 4.5 cm, greenish (light purple outside), green with dark purple streaks and spots inside, apex acute to acuminate pale yellow filiform, horizontally spread and slightly curved, bifurcated pointed or entire tip T. roxburghii 10-35 cm hastate, triangular, shallowly or deeply tri- lobed, 5-17 x 4-14 cm absent subequaling the spathe 12-15 cm, narrowly conical, dark purple, truncate, pale red stipe broadly triangular-ovate, 13-15 x ca. 5 cm, purple or purple mixed with a dirty green flush outside, inside deep rich purple, usually twisted apex yellow filiform, weakly papillose, arranged in 3 whorls, horizontally spread, pointing downward, acute tips Rijan Ojha et al.: A new species of Typhonium from Eastern Nepal For now, the new species is considered endemic to Nepal, but further re- search is necessary to confirm its distribution range, particularly the potential occurrence in India. Special attention should be given to critically studying specimens with globose bulbils. Acknowledgements We would like to thank the Division Forest office, Pathari Shanishchare, Morang district for providing permission for the fieldwork. We are thankful to Bivek Gau- tam for his contributions during fieldwork. We extend our gratitude to Wilbert Hetterscheid and Khant Zaw Hein for useful discussions and for sharing imag- es of Typhonium species. Additional information Conflict of interest The authors have declared that no competing interests exist. Ethical statement No ethical statement was reported. Funding RO acknowledges the ANSO scholarship for Young Talents to support his PhD, where- as HS acknowledges the financial support by the Yunnan Province Science and Tech- nology Department (202101AS070012), Yunnan Revitalization Talent Support Pro- gram “Innovation Team” Project (202405A350019), and the 14" Five-Year Plan of the Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences (E3Z- KFF8B01). Author contributions Field investigation, collection, and photography: SR. Specimen examination, description: RO. Original draft writing: RO, SR. Draft improvement and editing: HS. Author ORCIDs Rijan Ojha © https://orcid.org/0000-0002-8270-6343 Sudeep Rai © https://orcid.org/0009-0004-7697-9267 Harald Schneider © https://orcid.org/0000-0002-4548-7268 Data availability All of the data that support the findings of this study are available in the main text. References Hetterscheid WLA, Sookchaloem D (2012) Typhonium. 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