Ardisia (Tinus) dahoaiensis D. V. Hai & G. Hao, 2025
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publication ID |
https://doi.org/10.3897/phytokeys.260.154984 |
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https://doi.org/10.5281/zenodo.15985788 |
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https://treatment.plazi.org/id/47317BC7-CB17-5E12-AA0E-58350CC8A95C |
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scientific name |
Ardisia (Tinus) dahoaiensis D. V. Hai & G. Hao |
| status |
sp. nov. |
Ardisia (Tinus) dahoaiensis D. V. Hai & G. Hao sp. nov.
Figs 1 View Figure 1 , 2 View Figure 2
Type.
Vietnam • Lam Dong Province: Cat Tien District, Tien Hoang Commune ; 11°40'27.2"N, 107°22'23.4"E, 325 m alt., 8 October 2024 (fl. & fr.); Tran Trong Hung et al., DVH 448 (holotype HN!; isotypes HN!) GoogleMaps .
Diagnosis.
Ardisia dahoaiensis is the only species under this genus with the following combination of characters: leaves 6–12, alternate or forming a rosette, mainly clustered at the ends of branches, lamina subcoriaceous; margin entire or crenate in the upper part, with pustule-like structures along the crenations from projecting venation; inflorescence grows in extra axillary; flowers 5–7 merous; ovules ca. 16–18 arranged around on placenta.
Description.
Shrubs, 40–60 cm high, stem erect, usually not branched; young shoots villous, young stem pubescent; old stem smooth; base diameter ca. 5–7 mm. Leaves 6–12, alternate or forming a pseudo-verticillate, mainly clustered at the ends of branches; petioles 10–15 mm long, winged by the decurrent leaf base, covered with dense, white simple hairs; lamina subcoriaceous, with sparse black gland dots throughout abaxially, raised between the venation; leaf blade broadly elliptic or oblanceolate-obovate, 25–35 × 8–13 cm; young leaves purple, especially the veins, mature leaves dark green above, pale green beneath; base attenuate; margin entire or crenate in the upper part, with pustule-like structures along the crenations from projecting venation; apex acute, adaxial surface glabrous, abaxial surface copiously rusty villose especially on the midrib, and with many glandular dots, visible under hand lens; mid-rib flat above, raised below; lateral veins 12–18 pairs, irregularly spaced, with short intersecondary veins, slender, distinct but shorter than lateral veins, angle to the midrib about 45 ° - 50 °, arcuate upward and joining at the marginal vein, distinct on the adaxial surface, prominent on abaxial side; reticulation of veins visible. Inflorescence grows in extra axillary, 4–6 cm long, usually unbranched, 12–16 - flowered at the top, condensed racemose, forming short clusters or umbels; bracts foliaceous, linear to lanceolate, 3.5–3.8 × 0.6–0.7 cm, subsessile, apex acuminate, densely pubescent on both sides, margin revolute. Flowers 5–7 merous; pedicels purplish-red, 1.6–2 cm long, slender, puberulent. Calyx 5 - (- 7) lobed, 2.2–2.5 × 1.3–1.5 mm long, purplish-red, split to near base; lobes oblong-ovate, acute at apex; orange-pink punctate, margin minutely ciliolate, pubescent abaxially, glabrous adaxially. Corolla tube ca. 1.3–1.5 mm long, lobes 5 - (- 7), white to light pink except the pinkish along the mid-petal and pinkish base, covered with dense, brown gland dots, lobes broadly ovate, 6–6.5 × 4–4.5 mm, glabrous on both surfaces, apex acute and tips slightly folded inwards; stamens 5 - (- 7), yellowish, subsessile, anthers narrowly ovate-lanceolate, longer than filaments, 4–4.5 × 1.5 mm, apiculate, glabrous throughout, gland dotted abaxially, thecae not locellate, dehiscent by longitudinal slits. Ovary superior, ovoid, 1.5–1.6 × 1.3–1.4 mm, glabrous, gland dotted yellow; ovules 16–18 arranged around on placenta; style protruding beyond stamens, 2.5–3 mm long, irregularly curved and narrow to the apex, stigma minute. Fruit drupaceous, globose, 5 mm in diameter, young fruits green, glabrous, with gland dotted yellow, mature fruits red; pistil exists at the apex; exocarp thin, mesocarp white and soft, endocarp red and hard, has many longitudinally ribbed. Seed smooth, with holes at the base; endosperm white, thick, horizontal.
Distribution and habitat.
Endemic to Vietnam, Lam Dong Province (Da Hoai district); currently known only from the type locality. It grows under the shade of evergreen broad-leaved forest on soils and stone, at an elevation of 300–400 m alt.
Phenology.
Flowering and fruiting from September to October.
Etymology.
The specific epithet of the new species refers to Da Hoai district (Lam Dong Province) in the Central Highlands of Vietnam, where it was first collected.
Vernacular name.
Khôi tía.
Preliminary conservation status.
This new species has been collected from three localities in Da Hoai district, Lam Dong province. It is quite common, but forest habitats can be impacted by humans due to farming or infrastructure constructions, sometimes harvested in small amounts for medicinal use. Further surveys are needed to understand the threats at the type locality and if the species is distributed outside the current area, and until these data are obtained, the species is assessed as Data Deficient (DD) ( IUCN Standards and Petitions Committee 2024).
Additional specimens examined
(paratypes). VIETNAM, Lam Dong Province • Da Hoai District, Ha Lam commune , 17 September 2023, Tran Hung et al. DVH 17092023-1 ( HN, IBSC) • Trieu Hai Commune , 17 September 2023, Tran Hung et al. DVH 17092023-2 ( HN, IBSC); ( HN, IBSC) • Tien Hoang commune , 17 September 2023, Tran Hung et al. DVH 17092023-3 ( HN, IBSC) .
Notes.
The exact placement of the subgenus of the new species is not easy, and sometimes confusing. At first we thought it belonged to the subgen. Akomos, which is characterized by inflorescences that are always terminal or both terminal and axillary, on branches with spirally arranged leaves, with inflorescences at the distal portion of branches often without subtending leaves and distinctly pedunculate; leaf margin usually entire, sometimes dentate in the upper part; and the plants drying brown to chocolate-brown; calyx with lobes spread out at anthesis, little or not imbricate, plants generally scaly ( Hu and Vidal 2004). However, after a detailed examination of the specimens and descriptions of the species, we found that the described species has the following characteristics: the sepals are overlapping (Fig. 2 J, K View Figure 2 ), and young stem pubescent; old stem smooth; the lateral inflorescences arising directly from the main stem (Fig. 2 A View Figure 2 ), serrulate teeth toward the distal part of the margin (Fig. 1 C View Figure 1 ). These features are consistent with the subgen. Tinus Mez ( Hu and Vidal 2004; Utteridge et al. 2023).
Under Ardisia subgen. Tinus , Vietnam has 14 species ( Hu and Vidal 2004; Lien 2002, 18 speices in Thailand ( Larsen and Hu 1996). This new species is distinct from all known species of the subgen. Tinus . Among them, the new species has the most similar characteristics to the two species A. albomaculata and A. brunnescens (subgen. Akomos). In addition to the characteristics of different subgenera such as indumentum, sepals, inflorescens, it differs from A. albomaculata in the leaf texture, venation and position of inflorescence (i. e., subcoriaceous; lateral veins 12–18 pairs, irregularly spaced, with short intersecondary veins, slender, distinct but shorter than lateral veins, angle to the midrib about 45 ° - 50 °; inflorescence extra axillary, condensed racemose). It differs from A. brunnescens by the indumentum on leaves, calyx (i. e., adaxial surface glabrous, abaxial surface copiously rusty villose especially on the midrib, and with many glandular dots). The detailed comparison between A. dahoaiensis , A. albomaculata and A. brunnescens is given in Table 1 View Table 1 .
The new species has an unusual feature in that, besides the usual pentamerous flowers with five sepals and corolla lobes and five stamens, hexamerous-heptamerous flowers were frequently observed, possessing six to seven sepals, corolla lobes and stamens. This feature is different from A. albomaculata (5 - merous flowers). Furthermore, the population of this new species is quite close geographically to the A. albomaculata , distributed in Dong Nai province. However, the new species also has a different fruiting season compared to A. albomaculata (March). In addition, A. albomaculata also has the distinct characteristic of having scaly sepals (as observed from the type specimens [ P 00075000, P 00087802] placing it in subgen. Akomos [ Hu and Vidal 2004]). Taken together with the morphological differences from known species, it is apparent that the newly collected material indeed represents a species new to science, which we compared in detail to A. albomaculata and A. brunnescens and described here as Ardisia dahoaiensis D. V. Hai & G. Hao .
New records for Vietnam
| HN |
National Center for Natural Sciences and Technology |
| IBSC |
South China Botanical Garden |
| P |
Museum National d' Histoire Naturelle, Paris (MNHN) - Vascular Plants |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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