Research Article |
Corresponding author: Surapon Saensouk ( surapon.s@msu.ac.th ) Academic editor: Duilio Iamonico
© 2024 Piyaporn Saensouk, Surapon Saensouk, Khant Zaw Hein, Thawatphong Boonma, Anousone Sengthong, Sarayut Rakarcha.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Saensouk P, Saensouk S, Hein KZ, Boonma T, Sengthong A, Rakarcha S (2024) Studies on Typhonium (Araceae) of Thailand I: Typhonium vinicolor, a new species from Khon Kaen Province, Northeastern Thailand. PhytoKeys 246: 189-195. https://doi.org/10.3897/phytokeys.246.128778
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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.
Areae, Aroideae, Indochina, Northeastern Thailand, plant taxonomy
Typhonium
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 protologues 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 consider it to represent a taxonomic novelty, which is described and illustrated in the present paper.
The measurements and descriptions were based on freshly collected and/or alcohol-preserved material, processed according to the methods established by
Thailand • Northeastern – Khon Kaen Province, 13 May 2023, Surapon Ara001 (holotype KKU!; isotypes FOF!, MSU!).
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 pistillate anthesis, nearside spathe artificially removed. Photos by: Surapon Saensouk and Thawatphong Boonma.
Typhonium vinicolor is easily distinguishable from the other Typhonium species by having narrowly elliptic to elliptic-lanceolate leaf blades with a reddish-purple abaxial surface. An only exception is T. laoticum Gagnep. (
Small, deciduous, herbs, to 15 cm tall. Stem hypogeal, subglobose 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) 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 × 1.8–4.2 cm, narrowly elliptic to elliptic-lanceolate, or elliptic-oblanceolate, chartaceous, adaxially medium 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 intramarginal collective vein; higher order venation reticulate. Inflorescence solitary, subtended by a cataphyll; cataphyll up to 3.0 cm long, linear-lanceolate, membranous, 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 sessile, 8.0–9.0 cm long, nearly as long as or shorter than spathe; pistillate zone ca. 2 mm 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 naked, 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 widest 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, cylindric; stamens congested, not ostensibly arranged into staminate flowers, irregularly 4-lobed, 0.6–0.7 mm in diameter, pink or yellow, dehiscing by an apical 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, ivory-colored, base slightly attenuate, apex acute. Infructescence not seen.
The specific epithet is derived from the Latin “vinicolor” (wine-coloured), referring to the reddish-purple abaxial surface of the leaves.
Uttapit-See-Wine.
Flowering time in May.
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 ranging from 200 to 250 m a.s.l. The species shows optimal growth in sandy loam soil mixed with rocks.
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 Deficient’ (DD). Further research is necessary, as there is inadequate information 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.
Based on overall morphology, this new species is also similar to Typhonium griseum Hett. & Sookch. (
Regarding spathe and spadix structures, the new species also resembles Typhonium huense V.D.Nguyen & Croat (
Morphological comparison of Typhonium vinicolor and its allied species, T. griseum (
T. griseum | T. huense | T. laoticum | T. lineare | T. stigmatilobatum | T. vinicolor | |
---|---|---|---|---|---|---|
Leaf blade | orbicular, triangular cordate or narrowly ovate | triangular-cordate to deeply trilobed | lanceolate or elliptic-oblong | pedatisect with linear or linear-lanceolate lobes | deeply trilobed or pedatisect with ovate to oblong-ovate lobes | narrowly elliptic to elliptic-lanceolate |
Spathe tube | ca. 1 cm long, externally dirty white with brownish-red spots | ca. 1.5 cm long, externally pale green with purplish violet spots | 1.3–1.5 cm long, externally pink with brown striations and spots | up to 1.8 cm long, externally whitish-gray with blackish-gray striations and spots | ca. 1.3 cm long, externally pale green or dull white with black or brown spots | ca. 1.2 cm long, externally white or greenish-white with a dense dark purple mottling |
Spathe limb | ca. 10 times longer than spathe tube |
ca. 6 times longer than spathe tube |
4–5 times longer than spathe tube |
7–8 times longer than spathe tube |
10–12 times longer than spathe tube |
6–7 times longer than spathe tube |
Spadix | longer than spathe, ca. 13 cm long | as long as or slightly longer than spathe, up to 11 cm long | shorter than the spathe, ca. 7 cm long | as long as or slightly shorter than spathe, up to 17 cm long | as long as spathe, up to 17 cm long | nearly as long as or shorter than spathe, 8.0–9.0 cm long |
Staminodes | narrowly fusiform, sickle-shaped, curved downwards, white | fusiform, variously directed, yellowish white | clavate, perpendicular to the spadix axis or curved upwards, white | subulate or fusiform, variously directed, white or yellow | fusiform, perpendicular to the spadix axis or slightly curved downwards, dull white | clavate-fusiform, perpendicular to the spadix axis or slightly curved downwards, yellow |
Appendix | sessile, ca. 12 cm long, strongly arching, pale brown | stipitate, ca. 9 cm long, strongly arching, brown or violet | sessile, ca. 5 cm long, erect, pale brown | stipitate, ca. 15 cm long, strongly arching, brown or golden yellow | sessile, 14–15 cm long, strongly arching, dark brown | sessile, 6.2–7.0 cm long, erect or weakly arching, ivory-colored |
Thailand • Northeastern – Khon Kaen Province, 18 May 2024, Saensouk, Boonma & Sengthong, SS 24518 (FOF!).
The third author (KZH) is grateful to Alistair Hay for his expert advice and guidance in aroids research.
The authors have declared that no competing interests exist.
No ethical statement was reported.
This research was financially supported by Mahasarakham University.
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.
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
All of the data that support the findings of this study are available in the main text.