Typhonium vinicolor P. Saensouk, K. Z. Hein & Saensouk, 2024

Saensouk, Piyaporn, Saensouk, Surapon, Hein, Khant Zaw, Boonma, Thawatphong, Sengthong, Anousone & Rakarcha, Sarayut, 2024, Studies on Typhonium (Araceae) of Thailand I: Typhonium vinicolor, a new species from Khon Kaen Province, Northeastern Thailand, PhytoKeys 246, pp. 189-195 : 189-195

Typhonium vinicolor P. Saensouk, K. Z. Hein & Saensouk sp. nov.

Fig. 1

Type.

Thailand • Northeastern – Khon Kaen Province, 13 May 2023, Surapon Ara 001 (holotype KKU!; isotypes FOF!, MSU!) .

Diagnosis.

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. ( Gagnepain 1942), which shows similar leaf blades. However, T. vinicolor differs 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 spirals (vs. staminodes densely arranged in 2–3 spirals).

Description.

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.

Etymology.

The specific epithet is derived from the Latin “ vinicolor ” (wine-coloured), 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 ranging from 200 to 250 m a. s. l. The species shows optimal growth in sandy loam soil mixed with rocks.

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 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.

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 differ 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 anthesis 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 detailed comparison between T. vinicolor 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!) .

Figures

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 pistillate anthesis, nearside spathe artificially removed. Photos by: Surapon Saensouk and Thawatphong Boonma.