taxonID	type	description	language	source
03FE87FCFFF04974FF456C7AFC10E9AD.taxon	materials_examined	TYPE: — LAOS. Khammouane Province: Hinboun Dist., Ban Houana, 17.825 ° N, 104.675 ° E, alt. 287 m, 7 September 2024, S. Tagane, P. Souladeth, V. S. Dang, T. Vongthavone, K. Souvannakhoummane, P. Phonepaseuth, K. Phengmala, Q. T. Pham, T. Yamamoto, K. Yamazaki Z 1741 [fl.] (holotype FOF [FOF 0007156!], isotypes KAG [KAG 188404!, KAG 188405!], VNM).	en	Phengmala, Kajonesuk, Tagane, Shuichiro, Dang, Van-Son, Kongxaisavath, Deuanta, Yamamoto, Takenori, Souvannakhoummane, Keooudone, Phonepaseuth, Phongphayboun, Vongthavone, Thyraphon, Sengthong, Anousone, Trong, Pham Quoc, Yamazaki, Kaito (2025): Grewia souladethiana, a new species of Malvaceae from Laos. Phytotaxa 728 (1): 61-68, DOI: 10.11646/phytotaxa.728.1.6, URL: https://doi.org/10.11646/phytotaxa.728.1.6
03FE87FCFFF04974FF456C7AFC10E9AD.taxon	diagnosis	Diagnosis: — Grewia souladethiana is similar to G. thailandica Chantaranothai & Nualngam (2022: 2) of Thailand, in having acuminate leaf apex, axillary 2 ‒ 3 - flowered inflorescences, and erect peduncles, but distinguished by its tree habit (vs. scandent shrubs to woody climbers in G. thailandica), longer acumen of leaf blades (up to 2.8 cm long vs. up to 1 cm long), shorter petioles (0.6 – 0.9 cm long vs. 1.0 – 1.3 cm long), smaller sepals (18 mm long vs. 25 – 27 mm long), smaller and triangular petals 2.0 × 1.8 mm (vs. oblong or lanceolate, 8.0 ‒ 9.0 × 3.0 ‒ 4.0 mm), and solitary or 2 - lobed fruits (vs. (1 –) 3 – 4 - lobed) (Table 1).	en	Phengmala, Kajonesuk, Tagane, Shuichiro, Dang, Van-Son, Kongxaisavath, Deuanta, Yamamoto, Takenori, Souvannakhoummane, Keooudone, Phonepaseuth, Phongphayboun, Vongthavone, Thyraphon, Sengthong, Anousone, Trong, Pham Quoc, Yamazaki, Kaito (2025): Grewia souladethiana, a new species of Malvaceae from Laos. Phytotaxa 728 (1): 61-68, DOI: 10.11646/phytotaxa.728.1.6, URL: https://doi.org/10.11646/phytotaxa.728.1.6
03FE87FCFFF04974FF456C7AFC10E9AD.taxon	description	Description: — Trees, 3 ‒ 4 m tall. Indumentum simple or stellate hairs. Young twigs yellowish green in vivo, dark greyish brown in sicco, sparsely hairy, old twigs glabrous, lenticellate. Stipules linear, 5.0 – 8.0 mm long, almost glabrous on both surfaces. Leaves alternate; blades elliptic-oblong, ovate-oblong, 8.7 ‒ 18.9 × 2.9 – 6.0 cm, length / width ratio 3 – 3.2, adaxial surface pale green, dull brownish yellow, sparsely hairy, abaxial surface dull yellowish green, sparsely hairy, apex acuminate, acumen up to 2.8 cm long, base attenuate or obtuse, symmetric or asymmetric, margin serrate, basal veins 3, midrib prominent on both surfaces, secondary veins 6 ‒ 7 pairs, prominent abaxially, tertiary veins scalariform, distinct abaxially; petioles 0.6 ‒ 0.9 cm long, sparsely stellate hairy. Inflorescences axillary, solitary or in cluster of 2 - or 3 - flowered; peduncle 0.9 ‒ 1.4 cm long at anthesis, erect, sparsely hairy; outer bracts narrowly-lanceolate, 3.0 × 15 mm, apex acuminate, margin ciliolate, caducous; inner bracts 3, whorled, narrowly oblong-lanceolate, 2.0 × 3.0 mm, glabrous adaxially, sparsely hairy abaxially, apex acute, margin ciliolate, caducous. Flowers bisexual; pedicels 1.4 ‒ 1.7 cm long; mature buds oblong-obovoid, 1.9 × 0.6 cm. Sepals free, 5, oblanceolate, 18 × 3.0 mm, apex acute, adaxial surface glabrous, abaxial surface verrucose, sparsely hairy, 2 - grooved. Petals 5, free, triangular, 2.0 × 1.8 mm, glabrous on both surfaces, apex obtuse, margin entire, not ciliate, with clawed appendages, appendages glabrous on both surfaces, densely stellate hairy along margin, glands depressed globose. Androgynophore: lower part slightly grooved, 2.3 × 2.0 mm, glabrous; upper part cylindrical, 1.2 × 1.5 mm, densely hairy. Stamens numerous, filaments 2.8 ‒ 6.5 mm long, anthers 1.1 ‒ 1.3 mm long, glabrous. Ovary shallowly depressed globose, 1.8 mm in diam., hairy, 2 - locular, 4 ovules per locule, style 7.8 mm long, sparsely hairy at basal 1 / 5, stigma 4 ‒ 5 lobed. Fruits drupaceous, 1 ‒ 2 - lobed; lobes globose, 5.0 ‒ 9.0 mm in diam., sparsely hairy; stipe 1.7 ‒ 1.8 mm long. Seeds 2 per fruit, depressed obovoid-globose 4.0 × 7.0 mm, dark brown, scabrous, sparsely stellate hairy. Additional specimen examined: — LAOS. Khammouane Province: Gnommalath District, near Ban Tat, Phou Hin Poun National Protected Area (currently National Park), at the edge of evergreen forest on limestone hill, 17.54504 ° N, 105.06574 ° E, 206 m elev., 5 September 2024, S. Tagane et al. Z 1545 [fl.] (FOF [FOF 0006635], KAG [KAG 188212!], VNM); Thakhek District, Ban Pha Laem (Phatong), Phou Hin Poun National Protected Area (currently National Park), in open grassland on limestone hill, 17.5874 ° N, 104.824644 ° E, 190 m elev., 22 November 2024, P. Souladeth et al. Z 1959 [fl. & fr.] (FOF [FOF 0007028], KAG [KAG 200707]), Hinboun District, Ban Bouamlou, Phou Hin Poun National Park, at edge of disturbed semi-evergreen forest, 17.75929 ° N, 104.73403 ° E, 190 m elev., 29 June 2025, S. Tagane et al. Z 2740 [fl.] (FOF 0008005, KAG 202309, VNM).	en	Phengmala, Kajonesuk, Tagane, Shuichiro, Dang, Van-Son, Kongxaisavath, Deuanta, Yamamoto, Takenori, Souvannakhoummane, Keooudone, Phonepaseuth, Phongphayboun, Vongthavone, Thyraphon, Sengthong, Anousone, Trong, Pham Quoc, Yamazaki, Kaito (2025): Grewia souladethiana, a new species of Malvaceae from Laos. Phytotaxa 728 (1): 61-68, DOI: 10.11646/phytotaxa.728.1.6, URL: https://doi.org/10.11646/phytotaxa.728.1.6
03FE87FCFFF04974FF456C7AFC10E9AD.taxon	distribution	Distribution: — LAOS (Khammouane Province) (Fig. 1). Habitat and Ecology: — Grewia souladethiana grows at the edges of evergreen broad-leaved forests and in open grasslands on limestone hills, at elevations of 190 – 287 m. Phenology: — Flowering specimens were collected in June, September and November, and fruiting in November.	en	Phengmala, Kajonesuk, Tagane, Shuichiro, Dang, Van-Son, Kongxaisavath, Deuanta, Yamamoto, Takenori, Souvannakhoummane, Keooudone, Phonepaseuth, Phongphayboun, Vongthavone, Thyraphon, Sengthong, Anousone, Trong, Pham Quoc, Yamazaki, Kaito (2025): Grewia souladethiana, a new species of Malvaceae from Laos. Phytotaxa 728 (1): 61-68, DOI: 10.11646/phytotaxa.728.1.6, URL: https://doi.org/10.11646/phytotaxa.728.1.6
03FE87FCFFF04974FF456C7AFC10E9AD.taxon	etymology	Etymology: — The specific epithet honors Dr. Phetlasy Souladeth, a curator of FOF herbarium, Faculty of Forest Science, National University of Laos, who led our field surveys in Laos and encouraged the first author to intensively study on the Lao flora. Thanks to her, we could discover this new species. Vernacular name: — U ໍ ເƜ ̰ ື ƟƆffl ຸ Ð ະເ 00 (Por Leaung Souladeth) (suggested here). Preliminary conservation assessment: — Vulnerable (VU). Grewia souladethiana is endmic to Khammouane Province and currently known from four locations, all within the protected areas in Phou Hin Poun National Park (Fig. 1). In each population, we observed 10 – 50 individuals. The area of occupancy (AOO) and the extent of occurence (EOO) are calculated as 16 km 2 and 314 km 2, repsectively, using GeoCAT (Bachman et al. 2011). Based on these information, it may satisfy the criteria of Endangered (EN). However, considering G. souladethiana is locally common in forest edges and open grassland, which are frequently affected by human disturbance, it is likely to be more widely distributed within the national park (a total area 2,388.2 km 2) and its margins, we suggest its status as Vulnerable (VU) according to the critera B 1 ab (iii), 2 ab (iii) (IUCN 2024).	en	Phengmala, Kajonesuk, Tagane, Shuichiro, Dang, Van-Son, Kongxaisavath, Deuanta, Yamamoto, Takenori, Souvannakhoummane, Keooudone, Phonepaseuth, Phongphayboun, Vongthavone, Thyraphon, Sengthong, Anousone, Trong, Pham Quoc, Yamazaki, Kaito (2025): Grewia souladethiana, a new species of Malvaceae from Laos. Phytotaxa 728 (1): 61-68, DOI: 10.11646/phytotaxa.728.1.6, URL: https://doi.org/10.11646/phytotaxa.728.1.6
03FE87FCFFF04974FF456C7AFC10E9AD.taxon	description	Notes: — Among ten species of Grewia previously known from Laos, G. souladethiana might resemble G. abutilifolia. However, it can be easily distinguished by its tree habit (vs. shrubs in G. abutilifolia), shorter petioles 0.6 – 0.9 cm long (vs. 1.0 – 2.0 cm long), elliptic-oblong to ovate-oblong leaf shape (vs. ovate to nearly orbicular), longer pedicels 1.4 ‒ 1.7 cm (vs. 0.1 – 0.8 cm), more secondary veins (6 ‒ 7 pairs in G. souladethiana vs. 3 – 4 pairs), and triangular petals ca. 2.0 × 1.8 mm (vs. oblong, 2 – 3 × 1 mm) (Jussieu 1804, Phengklai 1993, Tang et al. 2007).	en	Phengmala, Kajonesuk, Tagane, Shuichiro, Dang, Van-Son, Kongxaisavath, Deuanta, Yamamoto, Takenori, Souvannakhoummane, Keooudone, Phonepaseuth, Phongphayboun, Vongthavone, Thyraphon, Sengthong, Anousone, Trong, Pham Quoc, Yamazaki, Kaito (2025): Grewia souladethiana, a new species of Malvaceae from Laos. Phytotaxa 728 (1): 61-68, DOI: 10.11646/phytotaxa.728.1.6, URL: https://doi.org/10.11646/phytotaxa.728.1.6
