[Botany • 2026] Syzygium khammouanense (Myrtaceae) • A New Species from central Laos

 

Syzygium khammouanense V.S.Dang, Tagane & Soulad.,

in Dang, Souladeth, Pham, Kongxaisavath, Phengmala, Sengthong, Souvannakhoummane, Vongthavone, Yamamoto, Tanaka, Takahashi et Tagane, 2026.

ຫວ້າຄຳມ່ວນ  ||  DOI: doi.org/10.1007/s12225-025-10351-3  

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Summary

A new species, Syzygium khammouanense V.S.Dang, Tagane & Soulad. (Myrtaceae), discovered from Khounkham District, Khammouane Province, central Laos, is described and illustrated. The new species is distinct from other Syzygium species by having 26 – 30 pairs of secondary veins and a strongly quadrangular hypanthium, 1 cm long. A description, provisional conservation assessment, photographs and vernacular name of the new species are provided.

Key Words: Indochina, Khounkham, limestone flora, plant diversity, taxonomy

Syzygium khammouanense V.S.Dang, Tagane & Soulad.
A flowering branch; B leaf, abaxial surface; C flower bud; D inflorescence; E flower, cutaway, showing stamens and style; F young fruits; G hypanthium, with style (left), and petals, adaxial surface (centre), abaxial surface (right). photos by: Shuichiro Tagane.

Syzygium khammouanense V.S.Dang, Tagane & Soulad. sp. nov. 

Etymology. The specific epithet “khammouanense” refers to the name of the province containing the type locality, in Laos.

Vernacular name. ຫວ້າຄຳມ່ວນ (Wa Khammouane, suggested here). “Wa” is the common Lao name for the genus Syzygium, and “khammouanense” represents the province’s name where the type material was collected.

 

Van-Son Dang, Phetlasy Souladeth, Quoc-Trong Pham, Deuanta Kongxaisavath, Kajonesuk Phengmala, Anousone Sengthong, Keooudone Souvannakhoummane, Thyraphon Vongthavone, Takenori Yamamoto, Nobuyuki Tanaka, Kotaro T. Takahashi and Shuichiro Tagane. 2026. A New Species of Syzygium P.Browne ex Gaertn. (Myrtaceae), S. khammouanense, from central Laos.  Kew Bulletin. DOI: doi.org/10.1007/s12225-025-10351-3 [21 May 2026] 

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[Botany • 2026] Saraca laotica (Malvaceae) • A New Species from Laos

  

Saraca laotica Tagane & Soulad.,

in Tagane, Phengmala, Kongxaisavath, Sengthong, Yamamoto, Phonepaseuth, Pham, Dang et Souladeth, 2026. 

ຄໍາລາວ  ||  DOI: doi.org/10.11646/phytotaxa.749.1.1 

 

Abstract

A new species of Saraca (Fabaceae-Detarioideae), S. laotica, is described and illustrated from Laos. It is characterized by leaflets with (9–)11–20 pairs of secondary veins, relatively larger, persistent and showy bracts of 1.4–3.3 × 0.6–0.9 cm, calyx tube of 27–36 mm, 4 stamens, anthers 1.9 mm long, by which combination, it is clearly distinguished from previously known species in the genus. Information on its habitat, phenology, vernacular name, and preliminary conservation assessment are also provided.

Detarioideae, endemic, Fabales, Leguminosae, limestones, plant taxonomy, Eudicots

Saraca laotica Tagane & Soulad.
A. Flowering branch; B & C. Portion of abaxial leaf surface; D. Hollowed twig inhabited by ants. E. Nest entrance on twig; F. Base of leaf showing petiole and petiolules; G. Young inflorescence; H & I. Bracts; J. portion of inflorescence, showing bracts and flower buds; K. Full-blooming inflorescence; L. Flowers, lateral view; M. Mouth of calyx tube showing ovary and filaments base; N. Bracteole (adaxial side); O. Anthers, adaxial (left) and abaxial (right) sides; P. Stigma; Q. Infructescence; R. Seeds.

Scale bars C, O & P = 1 mm, H = 5 mm, N = 2 mm, R = 1 cm. 

Photographed A & H from Tagane et al. Z1615, B, C, F, G, I–Q from Tagane et al. Z3281, D & E from Tagane et al. Z2639, R from Tagane et al. Z3281 (above three) and Z2639 (bottom), taken by S. Tagane.

  

Saraca laotica Tagane & Soulad., sp. nov.  

 

Diagnosis:—Similar to Saraca griffithiana and S. declinata in having persistent bracts and 4 stamens, but distinguished from the former by its midrib sunken adaxially (vs. prominent in S. griffithiana), longer bracts (1.4–3.3 cm long vs. shorter than 0.5 cm), and longer calyx tube (27–36 mm vs. 12–18 mm), and from the latter by more leaflets [5–9 pairs vs. 3–5(–7) pairs in S. declinata], more secondary veins [(9–)11–20 pairs vs. (6–)8–10(–12) pairs], larger bracts (1.4–3.3 × 0.6–0.9 cm vs. 0.3–1.2 × 0.1–0.7 cm), and longer anthers (1.9–2.2 mm vs. 0.75 mm long).

Etymology:—The specific epithet “laotica” refers to the country Laos, where the new species was discovered. 

Vernacular name:—ຄໍາລາວ (Kham Lao) (proposed here). In Lao, “Kham” means golden, referring to the color of the flowers, and “Lao” is the country name, indicating the locality where this species is found.

Shuichiro TAGANE, Kajonesuk PHENGMALA, Deuanta KONGXAISAVATH, Anousone SENGTHONG, Takenori YAMAMOTO, Phongphayboun PHONEPASEUTH, Quoc Trong PHAM, Van-Son DANG and Phetlasy SOULADETH. 2026. Saraca laotica (Fabaceae), A New Species from Laos. Phytotaxa. 749(1); 1-9. DOI: doi.org/10.11646/phytotaxa.749.1.1 [2026-03-25]

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[Botany • 2026] Firmiana laotica (Malvaceae) • A New Species from Limestone Karst, Khammouane Province, central Laos and Five New Records for the Flora of Laos

 

Firmiana laotica Sengthong, Soulad. & Tagane,

in Sengthong, Tagane, Souladeth, Dang, Yamamoto, Souvannakhoummane, Kongxaisavath, Phengmala, Tanaka et Pham, 2026.

DOI: doi.org/10.18942/apg.202523 

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Abstract

A new species, Firmiana laotica (Malvaceae), and five new records, Justicia oreophila (Acanthaceae), Aganosma wallichii (Apocynaceae), Colebrookea oppositifolia (Lamiaceae), Myristica yunnanensis (Myristicaceae), and Brachytome hainanensis (Rubiaceae) are reported for the flora of Laos. Voucher specimens, photographs, and ecological information in Laos are provided for each species.

Keywords: Central Laos, Firmiana laotica, flowering plants, Nam Kading NPA, Phou Hin Poun NP

Firmiana laotica Sengthong, Soulad. & Tagane.
A, habitat. B & C, habit. D, leafy twig. E, lower leaf surface. F, inflorescence. G, staminate flower. H & I, pistillate flowers. J, young fruits. All photos by Shuichiro Tagane.

Firmiana laotica Sengthong, Soulad. & Tagane, sp. nov. 

ປໍຜາລາວ

  Firmiana laotica is similar to F. fulgens (Wall. ex Mast.) K.Schum., but distinguished by leaf lobe apex (long-acuminate to caudate in F. laotica vs. acute to obtuse F. fulgens), lower leaf surface color (glaucous vs. not glaucous), depth of calyx lobes (lobed (1/3−)1/2 of calyx length vs. lobed 1/3–1/4 of calyx length), and number of stamens (15 in 5 groups of 3 vs. 20 or 25 in 5 groups of 4 or 5).

 

 Anousone Sengthong, Shuichiro Tagane, Phetlasy Souladeth, Van-Son Dang, Takenori Yamamoto, Keooudone Souvannakhoummane, Deuanta Kongxaisavath, Kajonesuk Phengmala, Nobuyuki Tanaka and Quoc Trong Pham. 2026. A New Species and Five New Records for the Flora of Laos. Acta Phytotaxonomica et Geobotanica. 77(1); 23-34. DOI: doi.org/10.18942/apg.202523 

 

ຂໍແນະນຳພືດຊະນິດໃໝ່ຂອງໂລກ ຈາກນິເວດພູຫິນປູນ (ບ້ານກອງລໍ ເຂດປ່າປ້ອງກັນພູໄຮ ແລະ The Rock at Phuphamarn ເມືອງຄູນຄຳ ແຂວງຄຳມ່ວນ)

ມີຊື່ວິທະຍາສາດ Firmiana laotica Sengthong, Soulad. & Tagane

ແລະ ໄດ້ໃຫ້ຊື່ລາວວ່າ ປໍຜາລາວ

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[Botany • 2026] Melastoma calcicolum & M. souladethianum (Melastomataceae) • Two New Species from Limestone Karst, Khammouane Province, central Laos

ເອນອ້າຂຸນກອງແລງ |  Melastoma calcicolum Souvann. & Tagane sp. nov.
ເອນອ້າເພັດຊົມພູ |  M. souladethianum Souvann. & Nob.Tanaka, sp. nov.

in Souvannakhoummane, Tanaka, Souladeth, Tagane, Dang, Yamamoto, Yamazaki, Pham, Phonepaseuth, Vongthavone, Phengmala, Kongxaisavath et Sengthong, 2026.  

DOI: doi.org/10.5852/ejt.2026.1034.3141

Abstract

Two new species, Melastoma calcicolum Souvann. & Tagane sp. nov. and M. souladethianum Souvann. & Nob.Tanaka sp. nov. (Melastomataceae), are described from limestone karst habitats in Khammouane Province, central Laos. Descriptions, photographs, distribution, habitat, phenology, and initial conservation statuses of both newly described species are given. A key to the species of Melastoma in Laos including currently reported species is provided. These discoveries result from extensive fieldwork conducted between 2022 and 2025 in protected areas including Phou Hin Poun National protected area and Phou Pha Marn area. M. calcicolum sp. nov. is distinguished from M. saigonenese by its terete twigs, narrow lanceolate leaves, spaced penicillate emergences on the hypanthium, stalk of emergences on hypanthium shorter, glabrous sepals, and longer styles, while M. souladethianum sp. nov. differs from M. pellegrinianum by its terete branches, small inflorescences with 2–4 flowers, and sparsely bristled hypanthium with strigose hairs. Both species are currently known only from their type localities, occurring in exposed limestone areas, and are preliminarily assessed as Endangered and Critically Endangered based on IUCN criteria due to their restricted distributions and small population sizes. These findings highlight the high botanical diversity and endemism of Laos’s limestone ecosystems and underscore the importance of continued botanical exploration in the region.

Keywords: Limestone flora, Myrtales, new description, new taxa, Southeast Asia

 

Melastoma calcicolum Souvann. & Tagane sp. nov.
 A. Habit. B. Abaxial leaf surface. C. Close-up of flower bud showing the penicillate emergences. D. Horizontal cross-section of ovary. E. Lateral view of flower. F. Top view of flower. G. Vertical cross-section of flower bud. H. Flower bud. I. Vertical cross-section of the flower with petals removed. J. Petals. K. Long stamens. L. Short stamens. M. Pistil. N. Bottom view of hypanthium showing the 5 sepals.

Photos from holotype (Tagane et al. Z1704) 

A, C by S. Tagane; B, D, G–N by K. Souvannakhoummane and E–F by P. Phonepaseuth.

Melastoma calcicolum Souvann. & Tagane sp. nov.

Diagnosis: Similar to Melastoma saigonense (Kuntze) Merr., but differs in its terete young twigs  (vs.  (sub)quadrangular), narrower leaves (ovate-lanceolate to lanceolate, length/width ratio 2.8–4.1 vs. ovate to elliptic, length/width ratio 1.8–2), penicillate emergences spaced apart (vs. densely covered by penicillate emergences), stalk of emergences on hypanthium 1–1.5 mm long (vs. 3–5 mm long), glabrous sepals except for ciliate margins (vs. outer surface densely covered with bristles), and longer styles (20–25 mm long vs. 15–20 mm long).

Etymology: The specific epithet refers to the limestone habitat.

Vernacular name: ເອນອ້າຂຸນກອງແລງ En R Khoun Kongleng (meaning: ʻKhoun Kongleng's Melastomaʼ).

Melastoma souladethianum Souvann. & Nob.Tanaka, sp. nov.
A. Habit. B. Abaxial leaf surface. C–D. Flowers. E. Petals. F. Hypanthium & pistil. G. Vertical cross-section of hypanthium showing ovary. H. Flower bud. I. Lateral view of young fruits. J. Top view of young fruit. K. Short stamens. L.  Long stamens. M. Lateral view of mature dry fruit. N. Top view of mature dry fruit. O. Vertical cross section of mature dry fruit.

C–L from holotype (Tagane et al. Z1213) and A–B; M–O paratype (Tagane et al. Z1915)

Photos by K. Souvannakhoummane.

Melastoma souladethianum Souvann. & Nob.Tanaka sp. nov. 

Diagnosis: Similar to Melastoma pellegrinianum (H.Boissieu) Karst.Mey., but it differs in having terete young branches (vs. quadrangular in M. pellegrinianum), inflorescences with 2–4 flowers (vs. more than 15), hypanthia sparsely covered in bristles with sparse strigose hairs (vs. bristles without strigose hairs).

Etymology: The specific epithet honors Dr. Phetlasy Souladeth, curator of the FOF herbarium of the National University of Laos, who led our field trips and is an excellent plant taxonomist. She has greatly contributed to elucidating the flora of Laos and has described more than 30 new species and recorded over 100 species to Laos’ flora.

Vernacular name: ເອນອ້າເພັດຊົມພູ En R Phetsomphou (meaning: purple diamond’s Melastomaʼ).

Keooudone SOUVANNAKHOUMMANE, Nobuyuki TANAKA, Phetlasy SOULADETH, Shuichiro TAGANE, Van-Son DANG, Takenori YAMAMOTO, Kaito YAMAZAKI, Quoc Trong PHAM, Phongphayboun PHONEPASEUTH, Thyraphon VONGTHAVONE, Kajonesuk PHENGMALA, Deuanta KONGXAISAVATH and Anousone SENGTHONG. 2026. Two New Species of Melastoma L. (Melastomataceae) from Limestone Karst, Khammouane Province, central Laos. European Journal of Taxonomy. 1034(1); 1-13. DOI: doi.org/10.5852/ejt.2026.1034.3141 [2026-01-08]

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[Botany • 2026] Heptapleurum karsticola & Trevesia laotica (Araliaceae) • Two New Species from the limestone karst of Central Laos

 Heptapleurum karsticola Kongx., Tak.Yamam. & Tagane,

in Kongxaisavath, Tagane, Yamamoto, Phonepaseuth, Dang et Souladeth, 2026. 

 ຕ້າງຜາຫອມ  ||  DOI: doi.org/10.11646/phytotaxa.737.1.1 

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Abstract

Two new species of Araliaceae, Heptapleurum karsticola and Trevesia laotica, are described from limestone karst in central Laos. Heptapleurum karsticola was found in Khammouane Province, and the second species, T. laotica, was found in Bolikhamxai and Khammouane Provinces. Information regarding the distribution, habitat, phenology, vernacular names, preliminary conservation assessment, DNA barcodes, and taxonomic notes compared to other closely related species is provided for each species.

Apiales, endemic species, Flora, Indochina, phylogeny, taxonomy, Eudicots

 Heptapleurum karsticola Kongx., Tak.Yamam. & Tagane 

 ຕ້າງຜາຫອມ

 Trevesia laotica Kongx., Soulad. & Tagane  

 ຜັກໜາມຕົ້ນ

Deuanta KONGXAISAVATH, Shuichiro TAGANE, Takenori YAMAMOTO, Phongphayboun PHONEPASEUTH, Van-Son DANG and Phetlasy SOULADETH. 2026. Two New Species of Araliaceae from the limestone karst of Central Laos.  Phytotaxa. 737(1); 1-16. DOI: doi.org/10.11646/phytotaxa.737.1.1 [2026-01-07]

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#ພູຫິນປູນ #ພູຜາມ່ານ #ແຂວງຄຳມ່ວນ 

ຂໍແນະນຳ 🌳ຕົ້ນໄມ້ 2 ຊະນິດໃໝ່ຂອງໂລກ ຕະກຸນຕ້າງ (Araliaceae) ໄດ້ຮັບການຕີພິມໃນວາລະສານ PHYTOTAXA 737(1): 001–016

1. Heptapleurum karsticola Kongx., Tak.Yamam. & Tagane (ໃຫ້ຊື່ລາວວ່າ ຕ້າງຜາຫອມ)

2. Trevesia laotica Kongx., Soulad. & Tagane (ໃຫ້ຊື່ລາວວ່າ ຜັກໜາມຕົ້ນ)

[Botany • 2025] Knema namkadingensis (Myristicaceae) • A New Species from Central Laos

 Knema namkadingensis Phengmala, Soulad. & Tagane, 

in Phengmala, Souladeth, Kongxaisavath, Sengthong, Souvannakhoummane, Dang, Yamamoto et Tagane, 2025. 

ເລືອດມ້ານ້ຳກະດິງ  ||  DOI: doi.org/10.11646/phytotaxa.732.3.2  

  Researchgate.net/publication/398357686

 

Abstract

A new species of Knema (Myristicaceae), K. namkadingensis is described from the Nam Kading National Protected Area, Bolikhamxai Province in central Laos. It is found growing in dry evergreen forest. The species can be distinguished from other species of Knema in Laos and surrounding countries by its small habit of up to 3 m tall, small leaves shorter than 10 cm long, small male flowers measuring 2.5–3 mm in diameter, and obovoid-ellipsoid fruits with acute apices.

Indochina, inventory, limestones, Magnoliales, taxonomy, Magnoliids

 Knema namkadingensis Phengmala, Soulad. & Tagane, sp. nov.:
A. Habit; B. Fruiting branch; C. Stem; D. Abaxial leaf surface; E. Male inflorescences; F. Male flowers; G. Detail of male flowers showing perianth (left) anthers (right); H. Fruit; I. Seed covered with aril.

Photos A-D, G-I by S. Tagane (from Tagane et al. Z1146), E-F by K. Souvannakhoummane (from Souladeth et al. Z662).

  Knema namkadingensis Phengmala, Soulad. & Tagane, sp. nov.  

Kajonesuk PHENGMALA, Phetlasy SOULADETH, Deuanta KONGXAISAVATH, Anousone SENGTHONG, Keooudone SOUVANNAKHOUMMANE, Van-Son DANG, Takenori YAMAMOTO and Shuichiro TAGANE. 2025. Knema namkadingensis, A New Species of Myristicaceae from Central Laos. Phytotaxa. 732(3); 247-252. DOI: doi.org/10.11646/phytotaxa.732.3.2 [2025-12-05] 

 Researchgate.net/publication/398357686_Knema_namkadingensis_a_new_species_of_from_Central_Laos

ເລືອດມ້ານ້ຳກະດິງ  ພືດຊະນິດໃຫມ່ຂອງໂລກ 

ຈາກປ່າສະຫງວນແຫ່ງຊາດນ້ຳກະດິງ ແຂວງບໍລິຄຳໄຊ 

[Botany • 2025] Grewia souladethiana (Malvaceae: Grewioideae) • A New Species from Laos

 

Grewia souladethiana Phengmala & Tagane, 

in Phengmala, Tagane, Dang, Kongxaisavath, Yamamoto, Souvannakhoummane, Phonepaseuth, Vongthavone, Sengthong, Trong et Yamazaki, 2025. 

ປໍເຫຼືອງສຸລະເດດ | DOI: doi.org/10.11646/phytotaxa.728.1.6 

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Abstract

Grewia souladethiana (Malvaceae-Grewioideae) is described and illustrated from Phou Hin Poun National Park, Khammouane Province, in central Laos. The new species grows at the edge of evergreen broad-leaved forest and in open grassland on the foot of limestone hills. To confirm the validity of the new species, diagnostic morphological characters were compared based on literature and herbarium materials at BKF, FOF, KAG an VNM as well as online digitized images. Morphologically it is similar to G. thailandica in having acuminate leaf apex, serrate leaf margin, and axillary inflorescences which are 2‒3-flowered and with erect peduncle, but distinguished by its tree habit, shorter petioles, smaller sepals and petals, and solitary or 2-lobed fruits. A description, photographs, line drawings, vernacular name and preliminary conservation status are provided for it, as well as a key to species of Grewia in Laos is provided.

Endemic, flora, Indochina, limestones, Malvales, Eudicots

 

Grewia souladethiana sp. nov. Phengmala & Tagane 

ປໍເຫຼືອງສຸລະເດດ  

Kajonesuk PHENGMALA, Shuichiro TAGANE, Van Son DANG, Deuanta KONGXAISAVATH, Takenori YAMAMOTO, Keooudone SOUVANNAKHOUMMANE, Phongphayboun PHONEPASEUTH, Thyraphon VONGTHAVONE, Anousone SENGTHONG, Pham Quoc TRONG and Kaito YAMAZAKI. 2025. Grewia souladethiana, A New Species of Malvaceae from Laos. Phytotaxa. 728(1); 61-68. DOI: doi.org/10.11646/phytotaxa.728.1.6 [2025-11-11]

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[Botany • 2025] Decaneuropsis phongnhakebangensis • Notes on Decaneuropsis (Asteraceae: Vernonieae) in Vietnam, with a New Species, a New Name for Vernonia balansae, and Two New Combinations

 

Decaneuropsis phongnhakebangensis  Tagane & V.S.Dang, 

iin Tagane, V. S. Dang, Q. T. Pham, Yamamoto, Souladeth, Souvannakhoummane, Phengmala, Masuda, Fujiwara, Nguyen, N. K. Dang et H. T. Pham, 2025.

DOI: doi.org/10.51033/jjapbot.ID0316  

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Abstract

A new species of Decaneuropsis (Asteraceae), Decaneuropsis phongnhakebangensis Tagane & V.S.Dang is described from Phong Nha-Ke Bang National Park in Quang Binh Province, North Central Region, Vietnam. A new name Decaneuropsis gagnepainii V.S.Dang & Tagane is proposed for the illegitimate name Vernonia balansae Gagnep. Two new combinations, D. bonapartei (Gagnep.) V.S.Dang & Tagane and D. macrachaenia (Gagnep.) V.S.Dang & Tagane, are proposed. A lectotype is designated for V. bonapartei. A key to species of Decaneuropsis in Vietnam is provided.

Keywords: Compositae, flora, lectotypification, limestone karst, new name, plant taxonomy, Vernonia

Decaneuropsis phongnhakebangensis.
A. Habit. B. Flowering branch. C. Abaxial leaf surface. D. Capitulum, top view. E. Capitulum, side view. F. Receptacle. G. Corolla opened out, showing stamens and style. H. Achenes with pappus. I. Achene.

Scale bars = 1 mm (F, I), 2 mm (G), 5 mm (H). Photos A–E taken by Shuichiro Tagane in the type locality on 10 December 2024.

Decaneuropsis phongnhakebangensis Tagane & V.S.Dang, sp. nov.

Nom. Vietnam: Bạch đầu phong nha kẻ bàng.

 

Similar to Decaneuropsis blanda (DC.) H.Rob. & Skvarla in the shape of leaves and capitula, but distinguished by its shallowly (4–)7–10-teethed leaf margin (vs. entire in D. blanda), eglandular stem, leaf blades, and achenes (vs. glandular), longer corolla 12.3 mm long (vs. 7–8 mm long), and longer and shallowly 11–12-ribbed achenes 5–5.8 mm long (vs. 10-ribed and 3–3.5 mm long) (Table 1).

...

Shuichiro TAGANE, Van Son DANG, Quoc Trong PHAM, Takenori YAMAMOTO, Phetlasy SOULADETH, Keooudone SOUVANNAKHOUMMANE, Kajonesuk PHENGMALA, Riko MASUDA, Tao FUJIWARA, Quoc Hung NGUYEN, Ngoc Kien DANG and Hong Thai PHAM. 2025. Notes on Decaneuropsis (Vernonieae, Asteraceae) in Vietnam, with a New Species, a New Name for Vernonia balansae, and Two New Combinations.  Journal of Japanese Botany. 100(4); 287-294. DOI: doi.org/10.51033/jjapbot.ID0316  [August 20, 2025] 

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[Botany • 2025] Lysionotus calcicola • A New Species from Limestone Karsts in north and central Laos, supported by morphological and molecular evidence [Studies on the Gesneriaceae in Laos II]

 

Lysionotus calcicola Phonep., Soulad. & Souvann.,

in Souvannakhoummane, Phonepaseuth, Souladeth, Lanorsavanh, Tagane et Tanaka, 2025. 

ດອກງາຊ້າງຫີນ  ||  DOI: doi.org/10.1002/njb.04620 

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Abstract

A new species of Gesneriaceae, Lysionotus calcicola Phonep., Soulad. & Souvann., is described and illustrated based on morphological and molecular evidence. This species is distributed in limestone karsts in the Luangprabang, Vientiane and Khammouane provinces in northern and central Laos. The new species can be distinguished from the hitherto known species in the genus by its deciduous shrubby habit, up to 2 m tall, and oldest stems with 4-rounded edges and longitudinal grooves, but young branches non-grooved, which are considered to be an adaptation to the severe environment in limestone karst and cliffs. ML tree based on ITS showed that the new species form a well-supported clade (94%), sister to the remaining Lysionotus species. Information on its distribution, ecology, phenology, vernacular name, and a provisional conservation assessment are provided.

keywords: Didymocarpoideae, flora of Laos, Indochina, Phou Pha Marn PPA, taxonomy

Lysionotus calcicola Phonep., Soulad. & Souvann.
 (A) Habit, (B) flower lateral view, (C) flower top view, (D) corolla opened out showing stamens and staminodes, (E) stamens and staminodes, (F) calyx, (G) pistil, (H) fresh fruit, (I) seeds.

Drawn from Souladeth et al. PPM034(FOF) by K. Souvannakhoummane.

Lysionotus calcicola Phonep., Soulad. & Souvann.
 (A-B) Habitat and habit, (C) 4-angled stem, (D) cross section of stem, (E) arrangement of leaves, (F) flower, font view, (G-H) inflorescences, (I) corolla opened out, (J) stamens and base of corolla tube, (K) calyx opened (L) pistil, (M) young fruit with calyx, (N) seeds.

 Photos from Souladeth et al. PPM034 (FOF). (A–F) and (L) by P. Phonepaseuth, (G–K) by K. Souvannakhoummane, (N) by D. Kongxaisavath.

Lysionotus calcicola Phonep., Soulad. & Souvann. sp. nov.  

Diagnosis: A species similar to Lysionotus chingii Chun ex W.T.Wang of China in having papery leaves, glabrous peduncles, white funnel-shaped corollas, and subulate seed appendages, but distinguished by its 4-rounded-angled and longitudinally grooved stems (versus terete), sparsely puberulent lamina (versus glabrous), corolla sparsely short glandular hairy on both surfaces (versus glabrous on outer surface), and sparsely glandular hairy pistil (versus glabrous). For further comparison see Table 2.

...

Etymology: The specific epithet refers to the Latin word ‘calcicola' meaning ‘growing on calcareous substrate', which is the habitat where this plant is found.

Vernacular name: Dok Nga Xang Hin (ດອກງາຊ້າງຫີນ), proposed here. ‘Dok Nga Xang' in Laos refers to a given name for the genus Lysionotus, and ‘Hin' refers to limestone karst, the type of habitat where this plant is found.

Keooudone Souvannakhoummane, Phongphayboun Phonepaseuth, Phetlasy Souladeth, Soulivanh Lanorsavanh, Shuichiro Tagane and Nobuyuki Tanaka. 2025. Studies on the Gesneriaceae in Laos II: Lysionotus calcicola, A New Species from Limestone Karsts in north and central Laos, supported by morphological and molecular evidence. Nordic Journal of Botany. DOI: doi.org/10.1002/njb.04620 [17 April 2025]

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[Botany • 2025] Orophea phouphamarnensis (Annonaceae) • A New Species from limestone karst in central Laos

 Orophea phouphamarnensis D.Kong., Soulad. & Tagane,

in Kongxaisavath, Tagane, Souvannakhoummane, Phengmala, Sengthong, Dang, Nguyen, Yamamoto, Tanaka, Takahashi et Souladeth, 2025. 

ຜາມ່ານອິນທີ  ||  DOI: doi.org/10.11646/phytotaxa.687.1.3  

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In Southeast Asia, approximately 408,000 km2 is covered with limestone, most of which was originally fragmented in distribution (Clements et al. 2006). In Laos, the limestone area is about 30,000 km2, covering ca. 12.6% of land in northern and central Laos. Khammouane Province, central Laos, is one of the core sites of limestone in the country where two main national protected areas, Phou Hin Poun National Protected Area and Hin Nam No National Park, are well known. In addition, the Nam Sanam-Phou Pha Marn Provincial Protected Area (hereafter PPA) covers an area of about 1,500 km2, in which the Rock Viewpoint Phou Pha Marn covers a huge area of the PPA.

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During our field surveys in the limestone karst of the Rock Viewpoint Phou Pha Marn, a species of Orophea was collected. After further comparisons with related taxa based on the literature and herbarium specimens, it was found to be a species of subg. Sphaerocarpon, morphologically most similar to O. laotica, but differing from all previously known species in the genus. Here, we describe it as a new species.

Flora, inventory, Magnoliales, Sphaerocarpon, taxonomy, Magnoliids

 Orophea phouphamarnensis.
 A. Flowering branch. B. Lower leaf surface. C. Inflorescence, top view and side view. D. Flower. E, F. Sepal (abaxial and adaxial). G, H. Outer petal (abaxial and adaxial). I, J. Inner petals (abaxial and adaxial). K. Stamen, L. Pistil.

 Photos A–C, K. Souvannakhoummane and D–J, L by D. Kongxaisavath of Tagane et al. Z994 (FOF).

Orophea phouphamarnensis D.Kong., Soulad. & Tagane, sp. nov.  

 Orophea phouphamarnensis is most similar to O. laotica in leaf shape and size but distinguished by a number of morphological features, especially stamen and carpel numbers (Table 1).

Etymology:—Referring to the type locality, Phou Pha Marn.

Vernacular name:—Pha marn Inthy (ຜາມ່ານອິນທີ; Lao), proposed here. Pha marn refers to an area, and Inthy refers to Inthy Deuansavanh, who established walking trails on the limestone karst that enabled access to the core area of Phou Pha Marn.

Deuanta KONGXAISAVATH, Shuichiro  TAGANE, Keooudone SOUVANNAKHOUMMANE, Kajonesuk PHENGMALA, Anousone SENGTHONG, Van-Son DANG, Quoc Bao NGUYEN, Takenori YAMAMOTO, Nobuyuki TANAKA, Kotaro T. TAKAHASHI and Phetlasy SOULADETH. 2025. Orophea phouphamarnensis (Annonaceae), A New Species from limestone karst in central Laos.  Phytotaxa. 687(1); 15-20. DOI: doi.org/10.11646/phytotaxa.687.1.3 [2025-02-13]

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[Botany • 2025] Memecylon longipedunculatum (Melastomataceae: Olisbeoideae) • A New Species from Coastal Areas of south central Vietnam

Memecylon longipedunculatum  

in Tagane, Dang, Truong, Q. B. Nguyen, Pham, T. V. Nguyen, Yamamoto, Kongxaisavath, Yamazaki, Nuraliev, Fomichev et Souladeth, 2025. 

Sầm cuống dài  ||  DOI: doi.org/10.11646/phytotaxa.683.1.1  

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Abstract

Memecylon longipedunculatum, a new species of Melastomataceae, is described and illustrated. The species is known to occur in Khanh Hoa and Ninh Thuan provinces in South Central Coast Vietnam, where it is restricted to low dry coastal forests and scrubby vegetation. The description is based on the authors’ original gatherings as well as on the historical collections made a century ago. The new species is distinguishable from most of its congeners by small leaves (1.2–5.7 × 0.7–2.4 cm) with obtuse or sometimes emarginate apices, long peduncles (1–2.7 cm long), and crescent-shaped anther connective with distinct centrally placed gland.

Indochina, Myrtales, taxonomy, Olisbeoideae, Eudicots

Memecylon longipedunculatum.
A, B. Flowering branches. C, D. Leaf, adaxial and abaxial side. E. Inflorescence. F. Flower, top view. G. Stamen, side view. H. Anther, side view. I. Post-anthetic flower (after abscission of petals and stamens). J. Mature flower bud.

Nuraliev & Fomichev NUR 4192 (A, E–J) and Nuraliev NUR 3340 (B–D). 

Photos by M.S. Nuraliev.

Memecylon longipedunculatum.
 A. Flowering branch. B. Abaxial leaf surface. C. Bark. D. Inflorescence. E. Top view of flower bud (up-left), anthetic flower (bottom), and post-anthetic flower (up-right). F. Inflorescence branch with anthetic and post-anthetic flowers. G. Fruiting stage of inflorescence.

Tagane et al. N465 (A, D–F) and Tagane et al. N216 (B, C, G). 

Photos by S. Tagane.

Memecylon longipedunculatum Tagane, V.S.Dang & Nuraliev, sp. nov.  

 Diagnosis:—Memecylon longipedunculatum is similar to M. chevalieri Guillaumin (1921a: 7, see also Guillaumin 1921b: 936) distributed in Cambodia, Laos and Vietnam by having axillary and terminal inflorescences with relatively long peduncles 1–2.7 cm long (vs. almost 1.5 cm long in M. chevalieri), but distinguished from the latter species by its smaller leaf blades (1.2–5.7 × 0.7–2.4 cm vs. 4–7 × 2–4 cm), longer pedicels (3.3–5.5 mm vs. 2–3 mm long), longer petals (ca. 4 mm vs. 2–3 mm long) with acute (vs. acuminate) apex, and subglobose (vs. ovoid-globose) fruits

Etymology:—The species epithet refers to its long peduncles (up to 2.7 cm long in flower and to 5.1 cm long in fruit), one of the remarkable features distinguishing it from most of its congeners in the Indochinese Peninsula.  

 Vernacular name:—Sầm cuống dài (Vietnamese).

Shuichiro TAGANE, Van-Son DANG, Ba Vuong TRUONG, Quoc Bao NGUYEN, Quoc Trong PHAM, Tran Vy NGUYEN, Takenori YAMAMOTO, Deuanta KONGXAISAVATH, Kaito YAMAZAKI, Maxim S. NURALIEV, Constantin I. FOMICHEV and Phetlasy SOULADETH. 2025. Memecylon longipedunculatum (Melastomataceae), A New Species from Coastal Areas of south central Vietnam. Phytotaxa. 683(1); 1-8. DOI: doi.org/10.11646/phytotaxa.683.1.1 [2025-01-29]

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[Botany • 2025] Nymphanthus adenophorus (Phyllanthaceae: Phyllantheae) • A New Species from central Vietnam

  

Nymphanthus adenophorus Tk.Yamam., Tagane & V.S.Dang

in Yamamoto, Dang, Souladeth et Tagane, 2025.  

Diệp hạ châu núi chúa  ||  DOI: doi.org/10.11646/phytotaxa.683.1.3 

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Abstract

A new species of Nymphanthus (Phyllanthaceae), N. adenophorus from Ninh Thuan Province, central Vietnam, is described and illustrated, along with its vernacular name and preliminary conservation status. The new species is similar to N. pireyi and N. nanellus, but distinguished by its terete and shorter floriferous branchlets with fewer leaves, larger leaf blades, faintly visible lateral veins, longer pedicels of male flowers, and accordion-folded discs of pistillate flowers.

flora, Indochina, Malpighiales, Phyllantheae, taxonomy, Eudicots

Nymphanthus adenophorus Tk.Yamam., Tagane & V.S.Dang (from Tagane et al. N226).
A. Habit; B, C. Floriferous branchlets showing adaxial and abaxial leaf surfaces respectively; D. Enlarged view of a part of a floriferous branchlet showing stipules; E. Lateral view of a staminate flower. One of four sepals was detached to show the internal morphology; F, G. Overhead view of a staminate flower. Sepals were detached in G to show four foveolate discs; H. Diagonally overhead view of a pistillate flower; I. Lateral view of a pistillate flower; J. Enlarged view of a young ovary with one of three bifid stigmas (the rest of two were destroyed during dissection); K. Young fruit.

 Abbreviations: an, theca of anther; dc, floral disc; ov, ovary; sp, stipule. 

All scale bars = 0.5 mm. All photos taken by T. Yamamoto.

Nymphanthus adenophorus Tk.Yamam., Tagane & V.S.Dang, sp. nov.  

 Among Nymphanthus species distributed in Vietnam and adjoining countries, N. adenophorus is similar to N. pireyi (endemic to Central Vietnam) and N. nanellus (endemic to South China) in having small leaf blades (≤ 1 × 1 cm) of ovate, suborbicular to obovate shapes, sepals of both staminate and pistillate flowers with non-fimbriate margins, and pistillate flowers bearing connate (not free) discs surrounding the lower portion of the ovary. However, the new species can be clearly ...

Etymology:—The specific epithet adenophorus is derived from the presence of many distinct glands on floral discs. 

Vernacular name:—Diệp hạ châu núi chúa.

 

Takenori YAMAMOTO, Van-Son DANG, Phetlasy SOULADETH and Shuichiro TAGANE. 2025. Nymphanthus adenophorus, A New Species of Phyllanthaceae from Vietnam.  Phytotaxa. 683(1); 18-24. DOI: doi.org/10.11646/phytotaxa.683.1.3 

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[Botany • 2025] Tetrastigma fruticosum (Vitaceae) • A New Species from Limestone Karst in central Laos

Tetrastigma fruticosum Soulad., Phonep. & Tagane, 

in Tagane, Souladeth, Phonepaseuth, Vongthavone, Kongxaisavath, Yamamoto et Murakami, 2025. 

DOI: doi.org/10.11646/phytotaxa.683.1.2 

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Abstract

A new species of Tetrastigma, T. fruticosum (Vitaceae), from the limestone karst in Khammouane Province, central Laos, is described. The new species can be distinguished from the previously known species in the genus by a combination of its shrubby habit, absence of tendrils, pedately 5-foliolate leaves (rarely 4, 6, or 7-foliolate) with shallowly emarginated leaflet, and 1-seeded oblong-ellipsoid fruits. A description, photographs, vernacular name and preliminary conservation status are provided for it.

Cayratieae, endemic, Indochina, phylogeny, Southeast Asian flora, Vitales, Eudicots

 

Tetrastigma fruticosum Soulad., Phonep. & Tagane sp. nov. 

Shuichiro TAGANE, Phetlasy SOULADETH, Phongphayboun PHONEPASEUTH, Thyraphon VONGTHAVONE, Deuanta KONGXAISAVATH, Takenori YAMAMOTO and Nariaki MURAKAMI. 2025. Tetrastigma fruticosum, A New Species of Vitaceae from Limestone Karst in central Laos.  Phytotaxa. 683(1); 9-17. DOI: doi.org/10.11646/phytotaxa.683.1.2  

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