Search

Two new species of genus Helicteres (Malvaceae, Helicteroideae), Helicteres Taynguyenenis and Helicteres dakmilensis from the Central Highlands of Vietnam are described and illustrated. H. taynguyenensis is morphologically similar to Helicteres angustifolia widely distributed in mainland SE Asia to China, Japan and Australia, but differs from the latter by having shorter petioles, larger calyx and petals, and longer androgynophores. Helicteres dakmilensis is closely related to Helicteres poilanei endemic to Vietnam, but distinguished by shorter petioles, fewer secondary veins, persistent stipules and bracts, larger calyx and fruits. The IUCN conservation status, vernacular name, illustrations, photographs, and comparison with the closest allies are provided for each of the new species.

Bulbophyllum tseanum was found in Quang Nam Province. It is a new record for the orchid flora of Vietnam. Previously this species was recorded in Hong Kong and Hainan (South-East China). Living specimens were collected in Quang Nam province and flowering successfully in a private garden in Da Lat city, Lam Dong province. Based on morphological characters, B. tseanum is very close to B. lepidum in the plant habit, shape, and color scheme of flowers, but can be distinguished by broadly ovate dorsal sepal, longer lateral sepals, narrow petals with shortly caudate apex, size of stelidia and column wing shape. The description of Vietnamese plants is presented, accompanied by the analytical plate and taxonomic notes.

Bulbophyllum phanquyetii, from Lai Chau Province was found and described as a new species for science. The new species looks similar to B. guttulatum and B. umbellatum but differs in the connate upper margin of lateral sepals, verruculose sepals and petals, and triangular stelidia. In addition, B. tianguii found in Ha Giang Province is firstly recorded for the orchid flora of Vietnam.

The paper provides a short annotated taxonomic review of Bulbopyllum sect. Tripudianthes from the flora of Vietnam along with a species-level key for identification. The section in Vietnam includes five species, one of which is a new species for science and described under the name, B. viridipallidum. The new species was found recently from Kon Tum Province of southern Vietnam. It is similar to B. kanburiense, B. khaoyaiense, and B. wallichii, but clearly differs by having pale greenish lateral sepals and two rounded calli at the lip base fused distally into a single prominent longitudinal keel; this is inflated at the lip apex into prominent half ovoid callus. In addition, we confirm the occurrence of B. wallichii in the flora of Vietnam. The taxonomic description, data on distribution, ecology, phenology, proposed conservation status, taxonomic notes, and the comparison of the new species with morphologically similar species are reported.

Hullettia King ex Hook. f. (Moraceae) is newly recorded to the flora of Vietnam. A specimen discovered in the lowland secondary evergreen forest of Song Hinh protection forest, Phu Yen province, central Vietnam was identified as Hullettia dumosa King ex Hook. f. It was earlier known from peninsular Myanmar, peninsular Thailand, peninsular Malaysia, Singapore, and Sumatra. Type material of this species is analyzed, and lectotype is designated (Scortechini s.n., K: K000898664). Photographic illustrations of studied specimens are provided. A key to the Vietnamese genera of Moraceae is presented.

A species, new to science, is described from Son La province, Vietnam. The new species is similar to B. yongtaiense, B. layae and B. sridithii in the hairy lip at base but clearly differs by the papillose margin and inner surface of dorsal sepal and petals, lip without mid keel and dense hairs on lateral keels, stelidia 2 times longer than 3 similar species.

The paper presents a taxonomic review of Bulbophyllum section Rhytionanthos for the flora of Vietnam and provides the key for its species’ identification. A new species, B. truongtamii and a new variety, B. taeniophyllum var. denticulatoalatum are described for science. Bulbophyllum nodosum is reported for the first time from the country. Bulbophyllum strigosum, described 20 years ago based on cultivated plant of uncertain origin was rediscovered in NE Vietnam. For this species, location and detailed description are reported. Analytical photos, data on phenology, ecology, and distribution are presented for all studied species. The morphological comparison table of the new species, new variety and newly recorded species segregating them from similar species are presented.

Gastrochilus pankajkumarii, found in the Central Highlands of Vietnam, is described as a new species for science. The protologue includes color analytical photos of the new species and data on phenology, ecology, and distribution. Morphological comparisons with similar species are presented.

A new species of Bulbophyllum (Orchidaceae), named as B. sondangii discovered in Da Lat Plateau (Da Lat Town area, Lam Dong Province of southern Vietnam) is described and illustrated. The new species is similar to B. andersonii and B. trongsaense, but can be distinguished by a short seta at the apex of median sepal and petals; almost entire margin of petals except the fimbriate apex; lip with auricles at base; and stelidia apiculate at apex. The paper presents the taxonomical description, data on distribution, ecology, phenology and conservation status, as well as notes and the comparison of the newly described plant with morphologically similar species.

AVERYANOV, LEONID V., THAI, TRAN HUY, NGUYEN, VAN CANH, TRUONG, BA VUONG, MAISAK, TATIANA V., DOAN, NGA THI, NGUYEN, KHANG SINH (2023): Averyanov L.V. et al.: (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 572 (1): 043-060. Phytotaxa 579 (1): 70-70, DOI: https://doi.org/10.11646/phytotaxa.579.1.9, URL: http://dx.doi.org/10.11646/phytotaxa.579.1.9

This paper presents new data on the orchid diversity of Vietnam obtained in 2020–2022. It comprises descriptions of two species new for science (Cleisostoma tatonii and Sarcoglyphis hiepii) and descriptions of four species new for the flora of Vietnam (Cleisostoma aspersum, Gastrochilus nanus, Micropera mannii and Trichoglottis ramosa). All species found for the first time in Vietnam are morphologically slightly different from the individuals in their main distribution area. Data on accepted names, main synonyms, etymology (for newly described species), morphological description, studied specimens, ecology, phenology and distribution, conservation status assessment, brief taxonomic notes, and illustrations are provided for each species listed.

The paper provides a short review of Bulbophyllum species recorded in Laos and Vietnam during the two last decades and continues the publication of results of our successive studies of the genus in this area. It presents data on two new species for science discovered in Laos (Bulbophyllum pachypodum) and Vietnam (B. neglectipetalum), one lesser known species for the flora of Laos (B. microtepalum), two new records for the flora of Vietnam (B. echinulus, B. setilabium), and new illustrated data on B. secundum insufficiently known in the flora of Vietnam. Bulbophyllum fascinator earlier accepted in specific rank reduced into the synonymy of B. putidum on the base of studies of newly obtained materials. Taking into consideration the new data presented in this paper, the flora of Laos presently includes 85, and flora of Vietnam 151 Bulbophyllum species, excluding Monomeria, Trias, and Sunipia. It is the largest genus in the orchid floras of both countries.

Dendrobium parahendersonii discovered in southern Vietnam is described as new species to science. It belongs to D. sect. Crumenata, and resembles D. hendersonii and D. exile in having a filiform, reed-like stem swollen at the base into a quadrangular ellipsoid pseudobulb and flowering from the leafless part of stem but differs clearly in the details of its tepals and lip. A morphological description, illustrations, data on habitat, phenology, and conservation status for the new species are provided.

Raphiocarpus taygiangensis, a new species of Gesneriaceae from Tay Giang District, Quang Nam Province, Central Vietnam, is here described and illustrated. The new species is diagnostic by the combination of its long stem, serrate leaf margin, purple spots, purple longitudinal lines, and glandular short hairs inside corolla. Morphological distinctiveness of the new species from the most similar species, Raphiocarpus axillaris, is discussed. The conservation status of this species is estimated as Vulnerable (VU D2) according to the IUCN Red List Criteria.

The new species discovered in Thanh Hoa Province of northern Vietnam described here as a new species for science. It is similar to B. muscicola but differs in smaller habit, inflorescence shorter than leaves, shorter lateral sepals with unequally lobed blunt apex, and slender stelidia. The newly described species also can be compared with B. japonicum but it differs in the size and shape of leaves, tepals, and lip. Detailed morphological description, illustration, data on distribution, and phenology of the new species are presented.

Zingiber magang and Z. tamii, two new species of Zingiber sect. Cryptanthium (Zingiberaceae) from central Vietnam are described and illustrated. Information on their distribution, ecology, phenology, uses and vernacular names are provided. A preliminary IUCN conservation assessment of each of these species is proposed. A key to species of Zingiber sect. Cryptanthium in Vietnam is also given.

A new variety, Bulbophyllum blaoense var. flavescences (B. sect. Cirrhopetaloides) discovered in southern Vietnam is described here. In addition, two species, B. caudatum and B. kwangtungense (B. sect. Desmosanthes) found in the northern part of the country are firstly recorded and documented for the flora of Vietnam. Morphological description and illustrations based on collected materials, data on phenology, distribution, and taxonomic notes are presented for newly recorded taxa. Lectotypes for B. bicolor and B. caudatum are proposed.

The new species, Gastrochilus dresslerii (G. sect. Microphyllae) discovered in northern Vietnam (Ha Giang Province) is described and illustrated, and data on its phenology, ecology, and distribution is provided. Morphological resemblance of discovered plant with allied species are also discussed.

An updated checklist of the family Burmanniaceae in Cambodia, Laos and Vietnam is provided. The checklist comprises a single genus, Burmannia, and 15 species, of which one is fully autotrophic, six species are partially mycoheterotrophic, and eight species are fully mycoheterotrophic (non-photosynthetic). Burmannia itoana earlier known only from Japan and China is reported from Vietnam for the first time, based on our collections of this species from northern and southern parts of the country. The newly recorded species, as well as a selection of several other Vietnamese species of Burmannia, are illustrated with analytical photographs of floral structure. A key for identification of Burmannia in the countries of Eastern Indochina is presented.

Bulbophyllum sridithii a new species to science is described and illustrated from Kon Ka Kinh National Park of Vietnam. The new species belongs to the section Cirrhopetaloides and resembles B. layae, B. hirundinis, B. electrinum, B. pecten-veneris and B. tingabarinum but differs in the size and shape of pseudobulbs, the shape of the leaf blade, and flower size. Morphological description, illustrations, data on habitat, phenology, and conservation status are provided.

The genus Octarrhena (Orchidaceae) is distributed predominantly in Malesia and Papuasia. Its presence in eastern Indochina was uncovered as recently as in 2015 simultaneously with a description of O. minuscula from the Central Highlands of Vietnam. Here, we describe two more species of the genus, O. emarginata and O. perpusilla, also endemic to this mountain system. All three Vietnamese species of Octarrhena are local endemics with very limited allopatric distribution. We summarize the current knowledge on the genus in Vietnam and present a key for their identification, and a map with location of all known populations. Finally, we briefly discuss modern views on the worldwide species diversity of Octarrhena.

Thismia is characterized by an exceptionally complicated floral morphology that is currently not understood properly. In the taxonomic literature, descriptive rather than morphological terms are often applied to parts of the flower in Thismia, relating to the general appearance of the floral organs instead of their precise homologies. Precise understanding of the floral structure is complicated by the rarity of Thismia spp. and the paucity of appropriate material. Here we provide a comprehensive study of reproductive organs of three Thismia spp. (T. annamensis, T. javanica and T. mucronata) including the first investigation of inflorescence architecture and early floral development in Thismiaceae. We found a hitherto unknown diversity of the reproductive shoots in the genus, manifested in the number of floral prophylls (two or three, in contrast to a single prophyll in the vast majority of monocots) and in the branching plane resulting in two distinct inflorescence types, a drepanium and a bostryx. We report the non-acropetal sequence of initiation of floral whorls (with stamens being the last elements to initiate), never previously described in monocots, and the gynoecium composed of completely plicate carpels, also a rare feature for monocots. Floral vasculature is relatively uniform in Thismia, but significant interspecific differences are found in tepal innervation, including the number of tepal traces; some of these differences are not immediately related to the external tepal morphology. We argue that the annulus, which acts as a roof of the hypanthium, possesses an androecium nature and represents congenitally fused bases of stamen filaments. We describe the stamens as laminar structures, which are also shortly tubular in the distal part of the supraconnective with the adaxial tubular side forming a skirt-like appendage. Finally, the placentas, which are column-like when mature, are initially parietal, becoming secondarily similar to free-central placentas through schizogenous separation from the ovary wall.

Vanilla tiendatii, discovered in limestone mountain area of Quang Binh Province in Northern Vietnam, is described as a species new for science. Morphologically this species appears to be closely related to V. yesiniana and V. albida, but well differs in the leaf shape, flower color, lip densely papillate-hairy at apex, and column fimbriate-hairy in the basal half. The key for identification of Vanilla species occurring in Vietnam is provided.

We present the first taxonomic account of the family Thismiaceae in the countries of Eastern Indochina. A single genus of Thismiaceae, Thismia, with eight species is known to inhabit this region. Six species, including four national endemics, are found in Vietnam, whereas Cambodia and Laos each has a single and endemic species of Thismia. We report new records of a number of species, which allowed us to establish for the first time their distribution areas. We show geographical distribution of all species of Thismia in Cambodia, Laos and Vietnam on a map. We recognise Hon Ba Nature Reserve and Chu Yang Sin National Park as hotspots of known Thismia diversity in Eastern Indochina. We confirm the presence of T. javanica in Vietnam, earlier known as a doubtful report, by specimen investigation. We significantly amend morphological descriptions of several Vietnamese species. We highlight a number of characters with remarkable intraspecific variation, along with the most important structural differences between morphologically similar species. We discuss remaining taxonomic problems of Indochinese Thismia, and present an identification key to species of Thismiaceae in Cambodia, Laos and Vietnam.

The orchid species new for science, Cylindrolobus chienii (Orchidaceae) discovered on Chu Mu Mountain, M’Drak District, Dak Lak Province of southern Vietnam is described and illustrated. It morphologically close to C. gloensis and C. bidupensis but differs from them in glabrous 2-flowered inflorescence, calli on labellum and character of the lip indumentum.

Diversity and taxonomy of the mycoheterotrophic genus Lecanorchis (Orchidaceae) in Vietnam is reappraised. Four species are confirmed, including two new records, L. moritae Suetsugu & T.C. Hsu and L. taiwaniana S.S. Ying. In addition, the occurrence of L. nigricans Honda in Vietnam is supported by image records, but further confirmation is still needed. Data of nomenclature, ecology, phenology, distribution, voucher specimens and brief taxonomic notes are provided for all Vietnamese species.

Lasianthus kbangensis V.S.Dang, Vuong & Naiki, a new species belonging to Lasianthus sect. Nudiflorae of Rubiaceae from the Central Highlands of Vietnam, is described and illustrated. This new species is similar to L. oblongilobus H. Zhu, but differs in having larger leaves, longer petioles, smaller calyx (calyx lobes) and corolla, and the color of ripen fruits. A table comparing the new species to closely related species is provided.

Pham, Phuoc Dien, Kumar, Pankaj, Dang, Van Son, Nguyen, Dinh Hiep, Bui, Van Huong, Tu, Bao Ngan, Dang, Minh Quan, Truong, Ba Vuong (2021): Notes on the genus Chamaeanthus (Orchidaceae, Epidendroideae, Vandeae, Aeridinae) with a new species from Vietnam. Phytotaxa 524 (2): 131-134, DOI: 10.11646/phytotaxa.524.2.9

Bulbophyllum xuansonii belonging to section Brachystachyae, discovered in Ninh Binh and Son La provinces is described here as a new species for science. This species is similar to B. xylophyllum and B. gracilipes but can be easily distinguished by the smaller habit and shape of tepals and stelidia. Additionally, B. gracilipes found in Lam Dong Province is reported as the species newly recorded for the flora of Vietnam. The paper provides analytical photos and data on phenology, ecology, and distribution of studied species. Morphological characters of the new species and similar species are shortly discussed. The key for identification of species of B. sect. Brachystachyae in Vietnam is also included.

The new species, Bulbophyllum manhdatii (B. sect. Brachyantha) discovered in Da Lat Plateau, Lam Dong Province (southern Vietnam) is described here. This new species is close to B. pumilio but clearly differs in densely crowded pseudobulbs and their shape, shorter inflorescence, lateral sepals forming a narrow acute tube slightly flattened at the base, lip without median keel, and longer stelidia. In addition, a new national record, B. seidenfadenii, from the same section is also reported from the first time from North Vietnam.

The mycoheterotrophic genus Thismia shows a great number of structural and ecological traits which are rare or unique for angiosperms. Pollen morphology of this genus is still poorly known. Pollen of Thismia was reported to be porate with one to several pores. Position of the pores is unknown, and therefore, the pollen type has not been established to date. Information on sporoderm structure in the genus is scarce, as high-quality images of pollen grains are available for several species only. In our comprehensive investigation of pollen morphology of Thismia, we involved nine Asian species of the genus and employed an integrative approach, which included data from light microscopy, scanning electron microscopy and transmission electron microscopy. All studied species were shown to possess monoporate pollen of asymmetric-elliptic planoconvex shape. Using TEM investigation of immature anthers, we demonstrated that pollen grains are organized in tetragonal tetrads, and the pore occupies an equatorial position. We argue that Asian species of Thismia along with Burmannia from the same order Dioscoreales are the only known lineages of seed plants with a single equatorial aperture. The sporoderm surface is psilate or perforate with perforations of various size and density in the studied species. We discuss the interspecific variation of sporoderm morphology in the light of the phylogenetic relationships between Asian species of Thismia. We demonstrate that the pollen morphology of Thismia fails to conform to the idea of entomophily, which is believed to prevail in this genus. Finally, we describe an unexpected striking difference in sporoderm structure between the specimens belonging to T. javanica species group.

Modern taxonomic revision of Bulbophyllum sect. Lemniscata in the flora of Vietnam based on available collections and literature data reports 5 species (Bulbophyllum averyanovii, B. chelicerum, B. comosum B. hirtum, and B. lemniscatoides), one of which (B. chelicerum) is described as a new for science. For all accepted taxa the paper provides valid name and main synonyms with appropriate standard taxonomic references, data on type and other authentic materials, description, data on ecology, phenology, expected conservation status, distribution, notes on biology and taxonomy, list of all studied materials, as well as key for identification of species and their color illustrations. Lectotype for B. lemniscatoides is proposed.

The paper continues publications of new data on orchid diversity in Vietnam (Averyanov and Gruss, 2018a-d; Averyanov et al., 2018a-e, 2019; Gruss et al., 2018) obtained in 2017–2018. It includes data on 4 orchid species new to science (Aerides phongthuyii, Cleisostoma uniseta, Macropodanthus brevidentatus and Schoenorchis tatonii) and 2 species new for the flora of Vietnam (Gastrochilus fuscopunctatus and Phalaenopsis malipoensis). The valid name, synonyms, type, citations of relevant regional taxonomic publications, data on ecology, phenology and distribution, estimated IUCN Red List status, studied specimens, brief taxonomic notes, and illustrations are provided for each recorded species. One new combination, Macropodanthus clausus (J.J. Sm.) Aver. (Sarcochilus clausus J.J. Sm.), is proposed.

The paper continues our recent publication of new original data on orchid diversity in Vietnam (Averyanov and Gruss, 2018a-d; Averyanov et al., 2018a-e; Gruss et al., 2018) obtained in 2017–2018. It includes data on 3 orchid species new for science (Coelogyne dolichopoda, Liparis robustior and Oberonia khuongii) and 5 species, new for the flora of Vietnam (Epigeneium nakaharae, Liparis bistriata, L. rhodochila, L. siamensis and Nervilia mackinnonii). Annotated species list provides the valid name, synonyms, type, citations of relevant taxonomic regional publications, data on ecology, phenology and distribution, estimated IUCN Red List status, studied specimens, brief taxonomic notes, and illustrations for each recorded species. Lectotype for Liparis siamensis is designated.