A taxonomic revision of Epirixanthes, the only mycoheterotrophic genus of Polygalaceae, is presented for Vietnam. Two species are recognized, of which E. elongata is known to be widely distributed across tropical Asia and E. kinabaluensis was considered endemic to Malesia prior to our study. Several nomenclatural inconsistencies are resolved for the names related to Epirixanthes. The original spelling of the generic name is confirmed as nomenclaturally correct because of being derived from conventional phonetic variants in Medieval Latin. Morphological descriptions of both Vietnamese species are significantly amended, reflecting novel data on the gross structure of their flowers and on intraspecific variation. For each species, the distinction from its most similar congener is summarized. Extensive illustrations of inflorescences and flowers of both species are provided; the inner structure of the intact flowers is illustrated with 3D images produced using X-ray microtomography.

A new species, Breynia phuongiana (Phyllanthaceae subgen. Sauropus), is described and illustrated from the Central Highlands of Vietnam. It is morphologically similar to B. beillei, B. bonii, and B. thorelii, but differs in having oblong-elliptic leaves, sepals marked with reddish striations, an androphore exceeding 1 mm in length, and distinctly hexagonal, starfish-shaped fruits with erect and persistent stigmas. A detailed morphological comparison with related species is provided. A preliminary conservation assessment categorizes it as 'Data Deficient' (DD) based on IUCN Red List criteria.

Perilimnastes dongchauensis (Melastomataceae), apparently endemic to Quang Tri province, Central Vietnam, is described here as a new species. It closely resembles P. suberalata in having elliptic-lanceolate leaf blades, few-flowered inflorescences, 4-merous flowers, and similar anther morphology. However, it differs in several key characteristics, with stems and petioles densely setose (vs. glabrous), leaves equal or subequal in a pair (vs. unequal, rarely subequal) and adaxial surface setose (vs. glabrous), hypanthia setose (vs. glabrous), calyx lobes narrowly triangular (vs. linear), and petals much larger, measuring 17–20 × 13–18 mm (vs. ca. 6 × 3.5 mm).

Begonia hanhhoae, a new species from Khanh Hoa Province, Ninh Hoa District, South Central Coast region, Vietnam, is described and illustrated. It resembles B. aspersa from northern Vietnam but differs in having broadly ovate to suborbicular leaves (vs. reniform) with a slightly waxy adaxial surface (vs. velvety), inflorescence with up to 13 flowers (vs. up to 5), actinomorphic androecium (vs. zygomorphic), and pistillate flowers that are subsessile or borne on very short pedicels up to 1.5 mm long (vs. 4-12 mm). According to the IUCN criteria, it has been tentatively assessed as Endangered (EN).

Begonia thanhquyetii, a new species from central Vietnam, is herein described and illustrated. It is morphologically most similar to B. baik in its creeping habit, rugose ovate leaves, and protogynous inflorescences. However, it differs in several key morphological characters, including stipules hirsute on the abaxial surface (vs. glabrous), bracts lacking glandular hairs along the margins (vs. glandular-ciliate), a pair of bracteoles present near the apex of the pistillate pedicel (vs. bracteoles absent), abaxial tepals of both staminate and pistillate flowers hirsute (vs. glabrous), and densely hirsute ovary (vs. glabrous). Following the IUCN Red List Categories and Criteria (Version 16), B. thanhquyetii is provisionally assessed as Least Concern (LC), pending further field surveys to clarify its distribution and population status.

Southeast Asia represents a major center of diversity for ferns and lycophytes. Within this flora, the genus Selaginella comprises some of the most taxonomically challenging groups, frequently characterized by ambiguous, continuous, or cryptic morphological traits. These complexities commonly lead to misidentifications in both herbarium collections and the published literature. A comprehensive revision of herbarium specimens deposited in Russian and Vietnamese institutions has yielded significant clarifications and new records. Our study documents several previously unreported occurrences: Selaginella subdiaphana, S. subeffusa and S. submonospora are newly recorded for the flora of Vietnam, and S. pulvinata is reported for the first time in Laos. Furthermore, we identify novel, specific distribution points for S. bodinieri and S. coriaceifolia in Vietnam, and for S. doederleinii and S. mairei in Laos. To stabilize taxonomic nomenclature, lectotypes are designated for S. mairei and S. elephantopus.

A morphological and molecular phylogenetic study of Selaginella specimens from Khanh Hoa, Dong Nai, and Dak Lak Provinces of Vietnam, previously identified as S. repanda, was conducted. As a result, it was concluded that these specimens represent a new species described here as S. pseudorepanda. Morphologically, this species resembles S. kurzii and S. repanda, but it is easily distinguished from them by having creeping main stems, a contiguous and imbricate arrangement of dorsal and ventral leaves on the main stems and branchlets, margins of ventral and axillary leaves densely long-ciliate, and ovate dorsal leaves with acuminate apex. The molecular phylogenetic analysis resolves S. pseudorepanda as a sister to S. minutifolia. Moreover, results of the spore morphology study also confirm that S. pseudorepanda is a distinct species.

Aspidistra congestiflora discovered in a karstic limestone area in central Laos (Vientiane Province, Vang Vieng District) is described and illustrated as a species new to science. It is characterized by obconoid perianth tube, triangular perianth lobes without appendages, and widely obconoid pistil with prominent longitudinal ridges. The new species is morphologically most close to A. zhangii, from which it differs in longer petioles and purple-violet flowers. In addition, A. congestiflora is similar to A. leucographa, A. longhuiensis, A. opaca, and A. papillata in the general flower appearance, but readily differs from these four species in obconoid pistil. Aspidistra congestiflora is also similar to A. obtusata in the shape of flower (including obconoid pistil), as well as in its general appearance, but differs in often finely verruculose perianth lobes, larger pistil with longitudinal ridges, and purple-violet stigma. The newly discovered species is expected to be a local endemic and will probably need protection in the near future.

Impatiens damrongii Shimizu, previously known as a native species of southern China, northern Laos, and northern Thailand, is found first in Vietnam, in the Nam Dong Conservation Area (Thanh Hoa Province). The voucher herbarium specimens of this species collected in Vietnam are housed in the herbarium of the Vietnam National University of Forestry. A morphological description of this species, accompanied by color photographs, data on ecology and phenology in Vietnam are additionally provided.

Two new species, Sonerila cornuta and S. phaluongensis, discovered in Vietnam, are described and illustrated. The first, superficially similar to S. reptans, however, it is distinguished by an obclavate hypanthium (vs. cylindrical-campanulate or obconical) and purple anthers (vs. yellow), with the base having two prominent S-curved lobes (vs. lobes at the base of anther short, inconspicuous). The second, is morphologically similar to Sonerila betongensis but differs in having a quadrangular, 4-winged stem (vs. terete), glabrous leaves (vs. densely hispid), shortly cylindrical hypanthium (vs. cupuliform to campanulate) that is sparsely covered with glandular hispid hairs (vs. relatively densely hispid with simple hairs), and the anther base with two prominent lobes (vs. small, inconspicuous). In addition to the formal description, line drawings, color plates, information on distribution, ecology, and conservation status, as well as comparisons with morphologically similar species, are provided for each species.

The paper presents new data on the orchid diversity of Vietnam obtained mainly during the fieldwork of 2023–2024, as well as a result of investigation of the herbarium and garden collections of Russia and Vietnam. It includes five species new to science, namely Cleisostoma truongquanii, Cymbidium bavuongii, Hemipilia uniflora, Micropera vietnamensis, Robiquetia binhii, and one variety, Biermannia averyanovii var. micrantha. Six species, Biermannia brachystachys, Cleisostoma nangongense, Coelogyne cumingii, Eulophia bicallosa, Gastrodia fontinalis, and Schoenorchis seidenfadenii are reported for Vietnam at first. For each of the studied taxa, their types, relevant synonyms, studied specimens, ecology and phenology (within Vietnam), distribution, preliminarily assessed conservation status, brief taxonomic notes and illustrations are provided. For the newly described taxa, morphological descriptions and notes on etymology are included. In addition, new nomenclature combinations, Panisea lecongkietii (Vuong, Aver. & Q.T.Truong) Aver., Biermannia brachystachys (Schltr.) Aver., Thrixspermum arunachalensis (A.N.Rao) Aver., and Thrixspermum jainiana (S.N.Hegde & A.N.Rao) Aver. are proposed. Based on available literature data and currently presented data the orchid flora of Vietnam includes 1382 species belonging to 184 genera.

An overview of the genus Osmanthus (Oleaceae) in Vietnam is provided. Four species are recognized, of which O. heterophyllus and O. yunnanensis are newly recorded for the country. Results of a molecular phylogenetic study are reported, and employed for clarification of the species idendity of the Vietnamese collections assigned to O. fragrans. In addition, uncertainties in phylogenetic relationships between the sections of Osmanthus are highlighted. For each species, taxonomic and nomenclatural notes are given, along with geographical distribution and analytical illustrations; accounts of the two newly recorded species are supplemented by morphological descriptions and notes on their ecology and phenology. Lectotypes are designated for three names currently treated within the genus Osmanthus. A key for identification of the Vietnamese species of Osmanthus is presented.

Vaccinium pseudobullatum W. P. Fang & Z. H. Pan, Acta Phytotax. Sin. 19 (1): 108 (1981). Fig. 2 Type. China. Yunnan Province • Malipo County, Tiechang, 1200 m a. s. l., 20 February 1940, C. W. Wang 86988 [fl.] (holotype: PE; isotypes: IBK, IBK 00302352!; IBSC, 0457816!; KUN, 12088909! & 12088910!; SZ, 00126560!; WUK, 0268189, image!). Notes. Based on the specimens cited in Appendix 1, we have clarified two androecial features of the species: The length of the stamen filaments was indicated in the protologue (Fang and Pan 1981) as 1–1.5 mm, which was repeated in Fang and Stevens (2005). Fang (1991) and Huang and Fang (1991) considered the range as 1–2 mm. In most of the specimens studied here, however, the filaments are 3–4 mm long. Both flowering gatherings listed by Fang and Pan (1981; Wang 86988 and Feng 13490) bear flower buds (and no fully open flowers), and we suppose it to be the reason that they indicate shorter filaments than those observed by us. Their description was likely reproduced in the subsequent account without additional investigation of flower structure. The ratio of anther tubules to thecae was uniformly indicated as 2–3 for this species (Fang 1991; Huang and Fang 1991, including fig. 105 (9, 10); Fang and Stevens 2005), whereas we observed it to be mostly 1.1–1.3. We therefore treat this feature as more variable than earlier thought. Distribution. S China (SE Yunnan, SW Guangxi), N Vietnam (Cao Bang, Ha Giang). Until recently, the species was considered to be endemic to Yunnan; it was reported from Guangxi by Wei (2023) and from Vietnam by Averyanov et al. (2020).

Vaccinium bidoupense Smitinand ex Y. H. Tong, N. T. T. Huong & Tagane sp. nov. Figs 3, 4, 5, 6 Type. Vietnam. Kon Tum Province • NW slopes of Ngoc Linh Mountain system at 1800–1900 m a. s. l., open places in primary evergreen dense mountain forest, 23 February 1995, L. V. Averyanov, N. T. Ban, N. Q. Binh, A. Budantzev, L. Budantzev, N. T. Hiep, D. D. Huyen, P. K. Loc, N. X. Tam, G. Yakovlev VH 053 [fl.] (holotype: HN!; isotypes: BRIT, BRIT 402341!; LE, LE 01041972!; MO, 5168102!; P, P 04485557! & P 04483084!). Diagnosis. Vaccinium bidoupense is morphologically similar to V. petelotii and V. pseudobullatum in its relatively large leaf blades and umbel-like inflorescence with short rachis. It differs from V. petelotii in having longer calyx lobes (5–6 mm vs. 2.5–3 mm), pale red to salmon pink (vs. pale green) corolla, a longer corolla tube (11–13.5 mm vs. 3.5–4.5 mm), and longer stamens (14–16 mm vs. 5–6.5 mm). The new species differs from V. pseudobullatum in having leaf blades with somewhat less obvious tertiary veins, and longer pedicels (7–14 mm vs. 4–7 mm), corolla tube (11–13.5 mm vs. 8–9 mm) and stamen filaments (8–9 mm vs. 1–4 mm) (Table 1). Description. Shrubs, epiphytic or epilithic, evergreen; shoots pendent, ca. 2–5 (– 10) m long, sometimes rooting at nodes. Branches more or less angled, glabrous, densely lenticellate. Leaves non-distichously alternate (but leaves of a branch often arranged in one plane due to twisted petioles), evenly scattered. Petiole 0.3–1.2 cm long, glabrous. Leaf blade ovate to lanceolate or sometimes elliptic, 12–22 × 4.7–11.7 cm, 2.0–3.7 times as long as wide, coriaceous; adaxial surface green, glabrous; abaxial surface pale green, densely covered with appressed dark brown trichomes (trichomes caducous, leaving faintly punctate scars); base rounded, subtruncate or shallowly cordate, rarely cuneate or prominently cordate; margin entire, slightly revolute, with 1 basal gland per side, glands 1–1.5 mm in diam.; apex acute to acuminate or shortly caudate; median vein and secondary veins impressed adaxially, strongly raised abaxially; secondary veins pinnately arranged, 10–14 on each side of median vein, usually meeting in a closed loop and forming an intramarginal vein; tertiary veins more prominent in submarginal area than in the rest of leaf blade, stout, reticulate, slightly impressed or sometimes flat adaxially, slightly raised abaxially. Inflorescences axillary, 1 per axil, on leafy shoots and older leafless branches, sessile (peduncle absent), racemose, umbel-like, determinate (developing mostly within the confines of the perennating buds), 4–10 - flowered; rachis pale green, 0.5–2 cm long, glabrous; bracts caducous, crimson, ovate, 1.0–1.5 × 0.5–0.6 cm, thinly coriaceous, glabrous, margin entire, apex obtuse. Flowers pendent, articulated with pedicels, 5 - merous. Pedicels red to pale green, 0.7–1.4 cm long, glabrous; bracteoles 2, attached at base of pedicel, subopposite, acicular, early caducous. Calyx (excluding ovary) pale red to salmon pink, becoming greenish with age, at base appressed to corolla and distally diverging to spreading, glabrous on both sides; tube ca. 1 mm long; lobes 5, triangular-lanceolate, 5–6 × 2–3 mm, distinctly 1 - veined. Corolla pale red to salmon pink, glabrous outside and inside; tube cupulate, 11–13.5 × 13–14 mm; lobes 5, strongly recurved, triangular to broadly triangular, 3–4 × 4–5 mm. Stamens 10, dimorphic with respect to spurs, included in corolla, free from each other, 14–16 mm long; filaments white to pale pink, slightly incurved, 8–9 mm long, glabrous in proximal half and puberulent in distal half; anthers tightly appressed to style, golden yellow, dorsifixed, 7–9 mm long, each with 2 spurs; thecae 3–3.5 mm long, slightly papillate; tubules parallel, 4–6 mm long (ca. 1.3 times as long as thecae), opening by oblique ventral apical pores; spurs borne dorsally at base of tubules, strongly curved, ca. 1 mm long, those on antesepalous stamens extending laterally outside of antepetalous anthers and overlapping with spurs of next antesepalous stamens, those on antepetalous stamens strongly hooked outward below spurs of antesepalous stamens. Ovary inferior, pale red to salmon pink, obconic, terete, 1–2 × 2–2.5 mm, glabrous, pseudo- 10 - locular; disk pale yellow, annular, broadly dome-shaped, ca. 2.5 mm diam., glabrous; style 1.4–1.6 cm long, exserted from corolla for 2.5–4 mm, linear, glabrous; stigma truncate. Infructescences with rachis 1–3 cm long. Fruiting pedicel 1.2–2.4 cm long. Fruit (when young) globose, ca. 6 mm in diam., glabrous, with persistent calyx lobes 5–6 mm long. Mature fruits and seeds unknown. Ecology and phenology. Vaccinium bidoupense grows as an epiphyte on tree trunks or as a lithophyte on mossy rocks in broad-leaved and mixed forests at elevations of 1100–2200 m. It flowers from October to February; young fruits are documented from May to June. Distribution. Vaccinium bidoupense is known from Laos (Sekong Province) and Vietnam (provinces Kon Tum, Lam Dong, and Quang Nam). The species is therefore endemic to the area comprising the Central Highlands of Vietnam (also called Tay Nguyen Plateau) and their extension in Laos known as Dak Cheung (or Dakchung) Plateau, being broadly distributed across this region. The region comprises three main mountainous areas, i. e., Dak Lak Plateau, Kon Tum — Gia Lai Plateau and Langbian Plateau (Poyarkov et al. 2021), and V. bidoupense is documented to inhabit the latter two areas. As the known locations suggest, the species probably occurs throughout the Central Highlands, and its presence in the provinces Dak Lak, Dak Nong and Gia Lai is especially probable. Etymology and history of documentation of Vaccinium bidoupense. The species name “ Vaccinium bidoupense ” was initially proposed by Tem Smitinand on the determination slips of three of Poilane’s specimens kept in P (30292, 30763 and 30909, included below as paratypes of the species). Two of these specimens originated from the Bidoup Massif (and 30292 was collected nearby), which is reflected in the species epithet. Although such a name has never been formally published until now, it was used by Vander Kloet and Avery (2007) (as “ V. bidoupense Smithin ”) who included the specimen Poilane 30763 in a morphophenetic analysis of stamen characters in the tribe Vaccinieae. Here, we follow Smitinand’s choice of epithet to ensure the clearness of the species identity and to acknowledge his recognition of this distinct species. Conservation status. Vaccinium bidoupense is an integral element of highland vegetation of the Central Highlands of Vietnam (including their extension in Laos) with an expected total extent of occurrence (EOO) of about 55,000 km 2, which does not fit any of the threatened IUCN Red List conservation categories (IUCN, Standards and Petitions Committee 2025). In intact habitats of montane forests, the species meets no damage factors. However, the vast degradation of primary vegetation across the distribution area of the species, including the legally protected territories, leads to a continuing decline in the extent of its occurrence, quality of habitat, number of populations, and number of mature individuals. In this connection, we preliminarily assess V. bidoupense as Near Threatened (NT); we also consider that the species is close to being qualified as Vulnerable (VU) in the near future. Additional specimens examined (paratypes). Laos. Sekong Province • [Dak Cheung District,] new road along the border with Vietnam, 15°34′36.0′′N, 107°20′11.5′′E, 1224 m a. s. l., 17 July 2021, P. Souladeth, M. Soukhavong, N. Thongphakdee, T. Boutavong 1141 [st.] (FOF, FOF 0009576; KAG, KAG 181621). Vietnam. Quang Nam Province • Nam Giang District, Song Thanh Nature Reserve, 15°33′07′′N, 107°23′02′′E, 1100 m a. s. l., 6 May 2019, M. S. Nuraliev 2509 [young fr.] (BRIT, BRIT 1150627; IBSC; MW, MW 0758862, MW 0758863 & MW 0758864). Lam Dong Province • N of Dalat, 1500 m a. s. l., 2 September 1940, E. Poilane 30292 [young fr.] (L, L.3786302, image; P, P 04484682, P 04484683, P 04484684, P 04484685, P 05244320 & P 05244322, images) • Bidoup Massif, 2200 m a. s. l., 12 October 1940, E. Poilane 30763 [fl.] (L, L.3786303, image; P, P 00647856, P 04484686, P 04484688, P 05244702 & P 05244703, images) • ibid., 2000 m a. s. l., 14 October 1940, E. Poilane 30909 [fl.] (P, P 04484687, P 05244317 & P 05244321) • Lac Duong District, Da Chay Municipality, 29 km to NE from Dalat City, 12°6′N, 108°39′E, 1900–2000 m a. s. l., 23 March 1997, L. V. Averyanov, N. Q. Binh, P. K. Loc VH 3118 [st.] (HN; LE, LE 01041973; MO, MO-5172316) • ibid., 12°6′N, 108°39′E, 2150 m a. s. l., 1 May 1997, L. V. Averyanov, N. Q. Binh, N. T. Hiep, P. K. Loc, P. Lowry VH 4463 [fr.] (HN; LE, LE 01041976; MO, MO 2080998; MW, MW 1045967; P, P 04483084) • Lac Duong District, Bidoup Nui Ba National Park, 12 October 2011, N. H. Xia, J. B. Ni, Y. H. Tong & X. R. Zheng TYH- 1070 [st.] (IBSC) • ibid., SE of Giang Ly station, 12°11′07.7′′N, 108°41′14.6′′E, 1509 m a. s. l., 23 December 2012, A. N. Kuznetsov, S. P. Kuznetsova, A. N. Demidova, N. G. Prilepsky 404 [st.] (MW, MW 0750311) • ibid., 12°10′21.03′′N, 108°41′49.76′′E, 1504 m a. s. l., 19 November 2014, H. Toyama, S. Tagane, V. S. Dang, H. Nagamasu, A. Naiki, H. Tran, C. J. Yang et al. V 1857 [fl.] (FU; VNM) • ibid., 12°11′11.18′′N, 108°42′53.12′′E, 1639 m a. s. l., 23 February 2016, S. Tagane et al. V 4287 [fl.] (DLU; FU; VNM) • ibid., 12°11′09.23′′N, 108°42′55.46′′E, 1637 m a. s. l., 22 December 2018, S. Tagane et al. V 9614 [fl.] (DLU; FU; KAG, KAG 127364) • ibid., 22 April 2019, T. Yahara et al. V 9879 [young fr.] (DLU; FU; KAG, KAG 182510) • ibid., 12°4.076′N, 108°38.927′E, 2000–2200 m a. s. l., 8 November 2023, L. V. Averyanov, V. C. Nguyen, B. V. Truong, T. Maisak AL 2537 [fl.] (LE, LE 01253935, photos LE 01124590).

After comprehensive morphological comparison, specimen examination, and phylogenetic relationship inference, a new climbing fig tree, Ficus flavifolia (Moraceae) is described and illustrated from central Laos. The new species shares some traits with the F. sarmentosa complex, such as distichous leaves, axillary solitary figs, and two free stamens, indicating the new species to be a member of the latter together with the phylogenetic results. The new species is sister to F. howii, but it is easily distinguishable from the latter by the well-developed indumentum on the leaves and syconia, yellowish-brown abaxial surface of lamina, thick branchlets, petioles, and peduncles, and ridges on the syconia.

The paper presents new data on the diversity of Aspidistra in Vietnam obtained during the fieldwork of 2025 in the Central Highlands (also known as Tay Nguyen Plateau). It includes four taxa new to science, viz. the species A. microstyla and A. nguyenii and the varieties A. brachypetala var. danii andA. mirostigma var. haui. Aspidistra brachypetala is reported here as a new species record for Vietnam. For each taxon, information on morphology, ecology, phenology, conservation status and distribution is presented, as well as relevant taxonomic notes and analytical photographic illustrations.

Peliosanthes mantegazziana, a nearly forgotten species described at the very beginning of the 20th century from Peninsular Malaysia, is re-examined. Peliosanthes graminea, which was established several years later based on material from Peninsular Thailand, is demonstrated to be identical to P. mantegazziana, and is therefore here reduced to its synonym. Morphological description of P. mantegazziana is updated, and its analytical photographs are published for the first time. Identity of P. mantegazziana with respect to the highly variable and broadly distributed P. teta is discussed.

Vaccinium petelotii Merr., Univ. Calif. Publ. Bot. 13 (6): 138 (1926). Fig. 1 = Agapetes parviflora Dunn, J. Linn. Soc., Bot. 35: 515 (1903). Type: China. Yunnan Province • Meng-tze [Mengzi County], A. Henry 10488 A [fr.] (lectotype, designated by Sleumer 1941: 446, US, 00116973, image!). Type. Vietnam. Lao Cai Province • Chapa [Sapa], 1500 m a. s. l., April 1925, P. A. Pételot 1772 [young fr.] (holotype: UC, UC 259692, image!; isotypes: A, 00015962, image!; P, P 00647843, image!; US, 00116935, image!). Notes. Based on the specimens cited in Appendix 1, we have clarified the morphological variation of the species as follows: In the treatments by Fang (1991) and Fang and Stevens (2005), Vaccinium petelotii is described as having corollas 6–11 mm long. However, the specimens of this species examined in our study bear corollas 4–5 mm long, consistent with the description by, e. g., Huang and Fang (1991) who indicated corollas about 6 mm long. At the same time, the specimen P. I Mao 82-172 (SWFC, 00004475 & 00004478) from Yunnan assigned to V. petelotii by R. C. Fang in 1984 demonstrates remarkably larger flowers with corollas up to 12 mm long. We suppose that the indications of large corollas were based solely on this specimen. Apart from flower size, this specimen differs from typical V. petelotii in larger leaves and shorter pedicels that remain straight (rather than becoming curved) when fruiting. We therefore exclude this specimen from V. petelotii and consider it a possible hybrid between V. petelotii and V. pseudobullatum. Fang and Stevens (2005) indicated the stamen filaments of Vaccinium petelotii as being 0.5 mm long, in which case the anthers would seem to be nearly sessile. We could not detect any reason for this indication and consider it erroneous because the specimens of this species studied here uniformly have filaments 2.5–3 mm long. The ratio of anther tubules to thecae was indicated by Fang and Stevens (2005) as ca. 3 for Vaccinium petelotii, which contradicts our observations (1.6–2.0) as well as the treatments by Fang (1991) and Huang and Fang (1991), both of which state a ratio of 1.5. Distribution. S China (SE Yunnan, SW Guangxi), N Vietnam (Lai Chau, Lao Cai).

Oreocharis sanglocii, a new species discovered in Hoang Lien Son Range of north-western Vietnam, is described and illustrated. The new species is characterized by leaf blade much longer than petiole and distinctly longer than wide, many-flowered inflorescence, light yellow to almost white corolla with purple-maroon markings at throat, narrow corolla tube constricted at throat, stamens with distally pubescent filaments and free (and not coherent) anthers, glabrous pistil and capsule, and peltate stigma. Oreocharis sanglocii is most close to O. blepharophylla, being readily distinguishable from it by more numerous secondary veins of leaf blade, inflorescence with up to 20 flowers, yellowish outer surface of corolla tube, hairy stamen filaments, and free anthers. The new species is also similar to the yellow-flowered O. tsaii and O. zhenpingensis. Available information on the species phenology, ecology and conservation status is presented, along with the taxonomic notes. This discovery is in line with the idea that within the territory of Vietnam Oreocharis is most diverse in the northern areas. It brings the number of species of the genus documented from Vietnam to twelve.

Vaccinium bidoupense, a new species of Ericaceae from the Central Highlands of Vietnam and their vicinity in Laos, is described and illustrated. The new species is morphologically similar to V. petelotii and V. pseudobullatum in its relatively large leaf blades and umbel-like inflorescence but differs in having the following combination of characters: pale red to salmon pink corollas, and longer pedicels, calyx lobes, corolla tubes and stamen filaments. The distinctness of V. bidoupense is further supported by its allopatric distribution relative to both V. petelotii and V. pseudobullatum. The range of morphological variation of V. petelotii and V. pseudobullatum is clarified, and their analytical photographic images are published for the first time. Additionally, the distinction between indeterminate and determinate racemes in Vaccinium is revisited, and the taxonomic history of Vaccinium sect. Calcicolus is summarized.