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| Typhonium mukdahanense Chatan & Promprom, in Promprom, Munglue, Phannasri et Chatan, 2026. |
Abstract
Typhonium is one of the most species-rich genera of Araceae in tropical Asia, with north-eastern Thailand representing an important but still incompletely documented area of diversity. During botanical surveys in northeastern Thailand, an unusual population of Typhonium was discovered in mixed deciduous forest and dry evergreen forest at 300–400 m elevation. Detailed morphological study of living plants and herbarium specimens, together with comparisons with relevant protologues, regional floras, and recently described species, confirmed that this population represents a species new to science. It is here described as Typhonium mukdahanense Chatan & Promprom, sp. nov. The new species is morphologically most similar to T. fornicatum, but differs by its taller habit, larger hastate to trisect leaf blades, more numerous primary lateral veins, larger and nearly symmetrical spathe tube, triangular reflexed spathe limb, dark red stigma with a cream-colored depressed center, sterile interstice bearing 10–14 staminodes arranged in two whorls, slightly curved and not spreading–declinate appendix, and pyriform mottled berries. It also differs from T. acetosella by its broader leaf blades, reflexed triangular spathe limb, dark red stigma, and pyriform fruits. The new species is currently known only from the type locality and is therefore provisionally assessed as Critically Endangered (CR) according to the IUCN Red List Categories and Criteria. A detailed description, diagnosis, information on distribution, habitat, phenology, conservation status, and an identification key to morphologically similar species are provided.
Keywords: aroid; Indochina; nomenclature; plant diversity
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| Typhonium mukdahanense. (A, B) Habitat and habit under natural field conditions; (C–F) Habit of cultivated plants; (G) Whole plant. |
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| Typhonium mukdahanense. (A) Tuber and roots; (B,E) Leaf blades (adaxial surfaces); (C,D,F) Leaf blades (abaxial surfaces). |
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| Typhonium mukdahanense. (A) Basal portion of the spadix showing the pistillate zone, staminodes, and sterile interstice; (B) Appendix; (C) Enlarged view of the pistillate zone, staminodes, and sterile interstice; (D) Pistils; (E) Enlarged view of a pistil; (F) Staminate zone; (G,H) Stamens in top and lateral views, respectively. |
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| Typhonium mukdahanense. (A, B) Naturally damaged infructescence in the field; (C, D) Infructescence before and after longitudinal sectioning. |
Typhonium mukdahanense Chatan & Promprom, sp. nov.
Diagnosis: Typhonium mukdahanense Chatan & Promprom, sp. nov., is most similar to Typhonium fornicatum in its clustered leaves and small inflorescences, but differs by its taller habit (up to 18 cm vs. up to 10 cm tall); larger hastate to trisect leaf blades (8–12 × 6.5–9.5 cm vs. 5.0–6.5 × 2.6–2.8 cm); more numerous primary lateral veins (5–8 vs. 3–4 per side of the midrib); larger and nearly symmetrical spathe tube (12–15 mm long vs. 8–9 mm long); triangular reflexed spathe limb with the adaxial surface facing upwards (vs. lanceolate and fornicate); longer spadix (9.5–10 cm vs. ca. 7 cm long); stigma dark red with a cream-colored depressed center (vs. white); sterile interstice bearing 10–14 staminodes arranged in two whorls (vs. only three staminodes arranged in single whorl); appendix slightly curved and not spreading-declinate (vs. spreading-declinate); and pyriform berries irregularly mottled or speckled with reddish- to purplish-brown markings (vs. clavate berries with darker brown mottling). A detailed morphological comparison between the new species and its most similar species is provided in Table 1.
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Etymology: The specific epithet refers to its type locality, Mukdahan Province, in northeastern Thailand.
Wilawan Promprom, Phukphon Munglue, Chuthep Phannasri and Wannachai Chatan. 2026. Discovery of Typhonium mukdahanense (Araceae), a New Species from Northeastern Thailand. Life. 16(8), 1376. DOI: doi.org/10.3390/life16081376 [20 August 2026]
