Pankaj Kumar, Stephan W. Gale, Henrik Æ. Pedersen, Thatsaphone Phaxaysombath, Somsanith Bouamanivong and Gunter A. Fischer
 Bulbophyllum alcicorne Photo: Stephan W. Gale  Bulbophyllum meson Photo: Thatsaphone Phaxaysombath  Bulbophyllum monoliforme Photo: Pankaj Kumar  Bulbophyllum scabratum Photo: Pankaj Kumar  Bulbophyllum seidenfadenii; Figure 87 from Seidenfaden (1973a)  Bulbophyllum seidenfadenii; Type specimen A.D.Kerr 2826 at Copenhagen (C); Photo: Henrik Æ. Pedersen  Bulbophyllum seidenfadenii in situ in China; Photo: Bingmou Wang Taxonomic notes on Bulbophyllum tipula: Averyanov et al. (2016b) described Bulbophyllum tipula from northern Vietnam, noting that it bears no clear affinity to any other known species and hence could not be assigned to any particular section. Wang et al. (2017) published B. lipingtaoi from China and compared it with B. japonicum, B. muscicola and B. omerandrum. According to their phylogram, the new species was found to be close to B. japonicum and hence they placed it in section Brachyantha Rchb.f. Bulbophyllum lipingtaoi shares virtually identical morphological traits and dimensions with B. tipula (diminutive, scrambling epiphyte with rugose pseudobulbs; inflorescence emerging from base of pseudobulb or rhizome node, bearing up to 3 sterile bracts; solitary flower with entire, ovate dorsal sepals, elongate lanceolate lateral sepals up to 2 cm long and a labellum lacking side lobes; column with a forward curving foot at base, small, rounded wings and minute, triangular stelidia). Malipo, the type locality of B. lipingtaoi, lies within 80 km of Bac Me District in northern Vietnam, and the habitat at both sites is humid evergreen forest on limestone karst above 1000 m elevation. We conclude that B. lipingtaoi should be synonymised under B. tipula. | Abstract: The following nine new additions to the orchid flora of Laos PDR are reported based on surveys in the country conducted during the period 2012–2017: Bulbophyllum alcicorne, B. meson, Coelogyne suaveolens, Cyrtosia nana, Dendrobium phuketense, Oberonia rhizoides, Phaius columnaris, Thelasis khasiana and Zeuxine longilabris. The taxonomy of a further 15 orchid taxa (Bulbophyllum guttulatum, B. moniliforme, B. sarcophyllum, B. scabratum, B. seidenfadenii, B. tipula, Cleisostoma lecongkietii, Coelogyne ovalis, Dendrobium chapaense, D. crepidatum, D. wattii, Habenaria gibsonii var. foetida, H. malintana, Luisia zeylanica and Phalaenopsis pulcherrima) native to Laos or adjacent countries is reviewed, resulting in the synonymisation of 20 names. In addition, new combinations are made for Grosourdya vietnamica, Luisia sonii and Holcoglossum gaoligongense to bring them in line with recent changes in the classification of the orchid family. Taxonomic notes on Bulbophyllum moniliforme: (...) Within Bulbophyllum, it is readily assigned to Section Minutissima Pfitz. on the basis of its minute pseudobulbs that give rise to a single leaf and a 1-flowered inflorescence, its tubular floral bract, free sepals, undivided labellum that lacks a cavity on the adaxial surface, and its column foot that is not swollen distally (Pridgeon et al. 2014). Recently, Rao (2017) reduced B. paramjithii to the synonymy of B. jejosephii. The distribution of each of B. subtenellum, B. paramjithii and B. jejosephii falls within the wider distribution range of B. moniliforme (Govaerts et al. 2017). Variation in the number of veins in the sepals from three to five gives rise to overlapping character states, as is evident from figure 4E in Averyanov et al. (2016b), which shows lateral sepals with both three and four veins in a single flower of B. subtenellum. In the absence of any decisive morphological differences, we conclude that B. subtenellum, B. paramjithii and B. jejosephii cannot be maintained as distinct from B. moniliforme. Taxonomic notes on Bulbophyllum scabratum: Following Govaerts et al. (2017), we have three species, B. psychoon (= B. lockii), B. levinei (= B. insulsum) and B. scabratum (= B. confertum), to take into consideration in resolving the taxonomy of this group of similar plants with overlapping distribution ranges in Indochina. All three show similar vegetative (clustered pseudobulbs; elliptic to lanceolate solitary leaf ca. 6 cm long) and reproductive morphology (peduncle with two sterile bracts; off-white flowers; labellum lacking sidelobes, apex tapering, longitudinally grooved on the upper surface; column shortly winged below the stigma, bearing two protruding stelidia 0.3–0.4 mm long). Bulbophyllum levinei has a dorsal sepal with an erose margin and divergent lateral sepals; in contrast, the dorsal sepal of B. psychoon is regarded as entire and the lateral sepals of this species are parallel; B. scabratum also has a dorsal sepal with an entire margin but its lateral sepals are either parallel or divergent. Variation in the placement of the lateral sepals, whether divergent, March 2018 Kumar et al.: Orchids of Indo-Burma Biodiversity Hotspot. 71 convergent or parallel, is sometimes observed in flowers on the same infloresence in Bulbophyllum (for example, as reported in B. retusiusculum by Lin & Wang 2014), hence this character cannot be considered significant for species delimitation. Furthermore, while studying living plants of B. levinei, we have observed that the margins of the dorsal sepal may appear entire when examined with the naked eye, but under a microscope they are certainly minutely erose. Similar observations were made with respect to B. lockii in Vietnam (Averyanov & Averyanova 2006, L. Averyanov, pers. comm.). We therefore find it likely that this character state has in many cases been overlooked by previous authors, and hence conclude that B. psychoon and B. levinei should be considered conspecific with B. scabratum. Global Distribution. Bhutan, Taxonomic notes on Bulbophyllum seidenfadenii: (...) Bulbophyllum seidenfadenii (Kerr 1973) and B. jingdongense (Hu et al. 2017b) both belong to the “Cirrhopetalum alliance” and exhibit similar vegetative morphology (pseudobulbs globose, subglobose or ovoid, oblique or not, wrinkled, olive-green or reddish-purple, 5.0–14.0 mm in diameter, 4.2–9.3 mm tall, placed at 2.5–12. 5 mm intervals and embedded in the rhizome to give the impression that the roots are emerging directly from the pseudobulbs; leaf solitary, elliptic, orbicular or ovate, acute or obtuse, equally or unequally 2-lobed, 7– 11 veined, dark to dull green above, purple underneath) as well as reproductive characters (peduncle 6–11 mm long, with 2–3 sheaths at base, bearing 4–6 purple-spotted flowers in an umbellate arrangement; labellum without sidelobes; column with broad stelidia), both of which are rather variable between plants. Although Hu et al. (2017b) reported the stelidia in B. jingdongense to be “basally truncate, apex acuminate, .…merging with the column wings at apex”, we find this description to be essentially consistent with the broad stelidia present in B. seidenfadenii. Hu et al. (2017b) also specifically mention the presence of a conspicuous gland below the stigma on the column in B. jingdongense, and although neither Kerr (1973) nor Seidenfaden (1973a) refer to an equivalent structure in B. seidenfadenii, re-examination of the type specimen confirms the presence of a distinct, transversely ellipsoid projection (we are unable to confirm whether this is a gland or not) on the ventral side of the column. Although rarely mentioned in descriptions of Bulbophyllum species, ‘glands’ below the stigma are not uncommon in the genus (e.g. Verma et al. 2015). Hence, we conclude that B. jingdongense should be regarded as a synonym of B. seidenfadenii. Taxonomic notes on Bulbophyllum guttulatum: (...) Bulbophyllum chyrmangensis was differentiated from B. guttulatum on the basis of its shorter inflorescence, fewer but larger flowers and the hairy margin of its labellum (Verma et al. 2015). Hooker (1890b) states the scape of B. guttulatum to be 6–10 inches (15–25 cm) long and equal to or exceeding the leaf, and the type specimen bears seven leaves with wide morphological variation. Seidenfaden (1992) provided a sketch from the type showing only four flowers in the inflorescence, whereas the illustration given by King & Pantling (1898) shows nine. Misra (2004), on the other hand, noted the length of the inflorescence in plants from central India to be 6–7 cm long. Most of these characters used for distinguishing the new species are therefore very variable and entirely overlapping with the morphology of B. guttulatum. Moreover, the distribution of B. chyrmangensis lies within the much wider distribution range of B. guttulatum (Govaerts et al. 2017). Given these observations, as well as the identical morphology of key species-level characters such as stelidia dimensions and orientation (filiform and projecting forward in both cases) and column wing outline (triangular in both cases), B. chyrmangensis is hereby synonymised under B. guttulatum. Taxonomic notes of Bulbophyllum sarcophyllum: (...) In terms of the creeping rhizome, discoid bulbs spaced at 3–6 cm intervals and enclosed by a deciduous sheath (or fibrous remains of the sheath once it has fallen away), the umbellate inflorescence with sterile bracts present on the base as well as in the middle of the peduncle, filiform stelidia 0.8–0.9 mm in length that project forward, and rounded column wings, B. cherrapunjeense is inseparable from B. sarcophyllum, and is therefore here reduced to the synonymy of the latter. As discussed in the notes given under B. sarcophylloides above, Pearce & Cribb (2002) already specified the holotype for B. sarcophyllum (Pantling 95, CAL), although the condition of this specimen is poor. Published in Taiwania 2018 vol.63 no.1 pp.61-83 DOI: 10.6165/tai.2018.63.61 http://tai2.ntu.edu.tw/taiwania/abstract.php?type=abstract&id=1544 |
