Oberonia brachystachys Lindl., Sert. Orchid.

Oberonia brachystachys Lindl., Sert. Orchid. View in CoL t. 8 B. 1838. Syntype s: BURMESE EMPIRE, s.loc., s.d., Griffith 697 (K!), Griffith 778 ( K!; P [ P00404973 ]!) ; possible syntype: Griffith s.n. ( K!) .

Oberonia recurva Lindl. , Edwards’s Bot. Reg. 25 (Misc.): 14. 1839. Lectotype (inadvertent designation by Ansari & Balakrishnan, 1990: 38 by reference to “ Type... (K)”): INDIA , Maharashtra, Bombay, s.d., Loddiges s.n. (K!), syn. nov.

Oberonia setifera Lindl., Fol. Orchid. 8: 3. 1859. Lectotype (inadvertent designation by Ansari & Balakrishnan, 1990: 38 by reference to “ Type... (K)”): INDIA , Maharashtra, South Koncan (= Koukan, Mumbai), s.d., Dalzell ex Stocks 38 (K!), syn. nov.

Oberonia demissa Lindl., Fol. Orchid. 8: 4. 1859. Lectotype (inadvertent designation by Seidenfaden, 1978: 37 by reference to “K, type”): INDIA , Sikkim, Terai, J. D. Hooker 121 (K!).

Oberonia gardneriana Thwaites, Enum. Pl. Zeyl. View in CoL 296. 1861. Syntype: SRI LANKA, Ambagamowa district , s.d., Gardner s.n. [ Thwaites] CP 593 (PDA n. v. fide Jayaweera, 1981 : see Notes). syn. nov.

Oberonia parvula King & Pantl., J. Asiat. Soc. Bengal, Pt. View in CoL 2, Nat. Hist. 64: 330. 1896. Lectotype (inadvertent designation by Ansari & Balakrishnan, 1990: by reference to “ Type: Pantling 203... (CAL)”]: INDIA View in CoL , Sikkim, valley of Teesta, 1500 ft, R. Pantling 203 (CAL [ CAL0000000040 About CAL ]!); isolecto AMES/HUH [ HUH00102050 ]!, BM [ BM000088303 ]!, G n.v.: fide Seidenfaden, 1968, K [ K000387743 ]!, P [ P0040885 ]!). syn. nov.

Oberonia croftiana King & Pantl., Ann. Roy. Bot. Gard. (Calcutta) 8: 7, pl. 6A. 1898. Lectotype (first-step inadvertent designation by Ansari & Balakrishnan, 1990: 38 by reference to “Type: ...(CAL)”; second-step designation here): INDIA , Sikkim, Tropical Valleys, October 1893, Pantling 254 (CAL [CAL0000000048: Tropical Valleys]!), isolectotypes (CAL [CAL0000000049]!; AMES [HUH 00101950]!, BM [BM000088297]!, BR [BR0000006572181]!, K [K000387742]!, P [P00404879]!). Residual syntypes: INDIA , Sikkim, Dikkeling [= Dikling], Pantling 254 L [L0061772]!; W [W5951]!); Locality unknown (G n.v.: fide Seidenfaden, 1968). syn. nov.

Oberonia lingmalensis Blatter & McCann, J. View in CoL Bombay Nat. Hist. Soc. 35: 255. 1931. O. recurva Lindl. var. lingmalensis (Blatt. & McCann) Santapau & Kapadia, J. View in CoL Bombay Nat. Hist. Soc. 57: 259. 1960. Holotype: INDIA View in CoL , Maharashtra, Western Ghats, Lingmala, near Yenna waterfall, a few miles from Mahableshwar [= Mahabaleshwar] on road to Panchgani, Blatter & Hallberg P 1681 (BLAT n.v.). Paratypes: INDIA View in CoL , Karnataka, North Kanara, in forests, Bell 5406 (repository unknown). Maharashtra, Kamelgad, below Fort (Fernandez I). Sedgwick 7755, 4626 (repository unknown). Maharashtra, Konkan, Thana [= Thane] forest, Bell 3972 (repository unknown). syn. nov.

Oberonia brachyphylla Blatt. & McCann, J. View in CoL Bombay Nat. Hist. Soc. 35: 257. 1931. Lectotype (designated here): INDIA View in CoL , Karnataka, North Kanara , Blatter & McCann (1931: pl. 2!). syn. nov. FIGS. 1–5 View FIG View FIG View FIG View FIG View FIG

Small erect or pendulous epiphytic herbs, usually 4–6 leaves, unjointed, forming stemless fan. Leaves variable in length, shape, typically elongated ovate acute, occasionally squat ovate acute, typically 2–6 cm long, 0.6–1.2 cm wide. Roots thin, fibrous, unbranched. Inflorescence typically 5–7 cm long, typically 1.5–3× as long as leaves. Scape short, rachis longitudinally grooved, flowers variously arranged from distinct whorls, to in spiral, or scattered. Flowers 0.75–1.5 × 1–1.75 mm, average ~1.5 × 1.5 mm, green, yellow, brown, orange, sometimes two-coloured with lip orange to brownish red, reminder greenish. Bract acuminate acute, margin irregular, about as long as flower. Pedicelled ovary round, ~ 1 mm long. Orientation of all tepals flat or somewhat forward. Sepals broad, oval, acute. Petals oblong, obtuse, erose to dentate. Lip typically four lobed, lateral lobes square or trapezoidal with tips towards epichile, margin typically erose to dentate, occasionally irregular; mesochile more or less constricted, entire; typically two distinct (occasionally indistinct) epichile lobes, truncated, rounded or falcate towards midline, margins dentate, erose, or occasionally irregular, disc indistinct, sac minute depression to large cavity.

Flowering: Flowering throughout the year with peaks in February and October ( Fig. 5a View FIG ). The break in June is considered a data artifact.

Habitat: Erect or pendulous epiphyte on branches of shrubs and trees in tropical wet or dry evergreen forest to subtropical montane forest, in association with Dendrobium ovatum (L.) Kraenzl. ( Orchidaceae ), on Carissa congesta L. ( Apocynaceae ), Anacardium occidentale L., Holigarna grahamii (Wight) Kurz , Mangifera indica L. (all Anacardiaceae ), Heterophragma quadriloculare (Roxb.) K.Schum. ( Bignoniaceae ), Garcinia indica Choisy ( Clusiaceae ), Elaeocarpus serratus L. (Eleocarpaceae), Euphorbia neriifolia L. ( Euphorbiaceae ), Erythrina suberosa Roxb. , Bauhinia racemosa Lam. (all Fabaceae ), Memecylon umbellatum Burm.f. ( Melastomataceae ), Tectona grandis L.f. ( Lamiaceae ), Careya arborea Roxb. ( Lecythidaceae ), Bombax ceiba L. ( Malvaceae ), Ficus arnottiana (Miq.) Miq. , F. benghalensis L., F. racemosa L., Artocarpus heterophyllus Lam. (all Moraceae ), Canthium dicoccum Gaertn. , Catunaregam spinosa (Thunb.) Tirveng. , Ixora brachiata Roxb. , Randia brandisii Gamble (all Rubiaceae ), Flacourtia indica (Brum.f.) Merr. ( Salicaceae ), Turpinia malabarica Gamble ( Staphyleaceae ). 0–2400 m, predominantly below 1800 m ( Fig. 5b View FIG ).

Distribution: Bhutan, China ( Guangxi?: see Notes), India, Malaya , Myanmar, Nepal, Sri Lanka, Thailand (Anonymous, n.d.b; Hooker, 1888; Cooke, 1907; Brühl, 1926; Blatter & McCann, 1931; Mitra, 1958; Seidenfaden & Smitinand, 1959; Santapau, 1967; Seidenfaden, 1978; Pradhan, 1979; Bose & Bhattacherjii, 1980; Jayaweera, 1981; Banerji & Pradhan, 1984; Ansari & Balakrishnan, 1990; Naithani, 1990; Seidenfaden & Wood, 1992; Turner, 1995; Sakkar, 1995b; Srivastava, 1996; Bose et al., 1999; Kress et al., 2003; Lucksom, 2007; Misra, 2007; Raskoti, 2009; Chen et al., 2009 Cerejo-Shivkar & Shinde, 2015; Jalal, 2018; Singh et al., 2019: see Notes). Some of the eastern distributional records (Malaya, Thailand) may be due to confusion of O. brachystachys with O. subligaculifera . The distribution based on type material of the O. brachystachys and its synonyms extends from India , Sri Lanka, to Myanmar.

Specimens examined: INDIA , Kerala, Kannur , Aralam Wildlife Sanctuary, N 11°552 512 2, E 75°482 452 2 ± 110 m, 29.12.2019, M . Sulaiman 145464 MH [ MH00257633 ] . Maharastra, Western

Ghats, Lingmala near Mahabaleshwar, Townsend

73/10 (K). Sikkim, valley of theTeesta, 1898, R. Pantling 238 (BM [BM000088265],CAL

[CAL0000077889], MEL [MEL2409511A], MH [MH00042702], P [P00404975], P[P00404976], US [ US 00241398], WU).

Notes: Oberonia brachystachys is characterized by the relatively small size of the plant, unjointed leaves,

bracts that are about as long as the pedicellate ovary, small flowers (0.75–1.5 × 1.0– 1.75 mm according to protologues, average ~1.5 × 1.5 mm), strongly erose, ovate petals, and a variable lip typically with quadrate lateral lobes with strongly erose margins, a more or less constricted and entire mesochile, and more or less developed diverging epichile lobes with strongly erose margins.

Oberonia brachystachys has two recognized synonyms, O. demissa and O. bambusicola Kerr (Seidenfaden & Smitinand, 1964; Bunpha et al., 2019). Oberonia demissa is here confirmed as synonym of O. brachystachys , while O. bambusicola is synonymized under O. subligaculifera (see below). Below we discuss each of the synonyms in greater detail.

Three main forms have been recognized, distinguished by the unnotched epichile of O. brachystachys vs. deeply incised epichile and more or less rectangular epichile lobes of O. recurva vs. lip with falcate epichile lobes of O. parvula . Those three morphs represent points along a spectrum of continuous variability. The three lips illustrated by Ansari and Balakrishnan (1990: fig. 36) under O. recurva show variation from shallow notch to deep incision, clearly documenting the intraspecific variability. Illustrations of O. brachystachys ( Fig. 1 View FIG ) and its synonyms O. parvula , O. croftiana ( Fig. 2 View FIG ) show intermediate character states of the epichile lobes quadrate, rounded, and falcate.

Differences in drawings from the same plant as demonstrated here with O. setifera ( Fig. 1g –i View FIG ) further caution the reliance on minute details in drawings. Floral variability has been confirmed with molecular data in O. equitans (G.Forst.) Mutel by Geiger et al. (2020) is also evident in the work of Li et al. (2016) (see Geiger et al., 2020 for details).

Oberonia recurva View in CoL ( Fig. 1c View FIG ) is a synonym of O. brachystachys View in CoL . Both species were introduced by Lindley (1838, 1839). Oberonia recurva View in CoL was described with erose petals ( petalis obovatis subdentatis), and a four-lobed lip ( labello subrotundo quadrilobo denticulato mucrone interjecto). It was only compared to O. wightiana Lindl. View in CoL , with a much larger flower, linear almost entire petals, and with lateral lobes folded over the midline of the flower. It is a typical case where a new species is justified by comparison to a very dissimilar species, as opposed to the most similar ones. The lectotype at K agrees with the protologue.

While several names have been considered synonyms of O. recurva View in CoL ( O. setifera View in CoL , O. gardneriana View in CoL , O. parvula View in CoL , O. croftiana View in CoL , O. lingmalensis View in CoL , O. myriantha var. parvula View in CoL : Jayaweera, 1981; Ansari & Balakrishnan, 1990; WCSP, 2020), those have not been discussed and justified and are treated here in more detail.

Oberonia setifera Lindl. ( Fig. 1g –j View FIG ; not to be confused with O. setigera Ames from the Philippines) was described with awn-shaped petals ( petalia setaceis), and a four-lobed, denticulated lip, and its small vegetative size was noted. The flowers were referred to as being perhaps the smallest in the genus. The lectotype at K agrees with O. brachystachys . The description of the petals is odd and may be the result of folded over petals.

The drawings on the type sheet of O. setifera by three different authors are illuminating, as it demonstrates the range of interpretations based on the same specimen. Lindley’s drawing ( Fig. 1g View FIG ) has rather narrow petals as noted in the protologue and the four lobes of the lip are rather different from the other drawings, but show an erose margin of the lip. The drawings by Hooker ( Fig. 1h View FIG ) and A. S. [? handwriting difficult to read] ( Fig. 1i View FIG ) show the erose and wider petals, and a more typical four-lobed lip. The drawings by Hooker do not show the erose margin of the lip, while that of A. S. illustrates it very clearly. Either those differences are due to artistic license or due to minute differences of flowers from the same plant. Regardless, it shows that those difference are meaningless at the species level and are either variability or artistic license .

Oberonia demissa ( Fig. 1d–f View FIG ) is a synonym of O. brachystachys . The small plant with small flowers has unjointed leaves and strongly erose petals. The lip was described by Lindley (1859) as trifid with ovate acute middle lobe [= epichile]. That condition is shown in a drawing ( Fig. 1d View FIG : presumably by Lindley) on the lectotype at K. A second drawing of the flower by J.D. Hooker ( Fig. 1e View FIG ), who collected the plant, shows the more typical four-lobed lip of O. brachystachys . The lobes are shown not as large and distinct as is typical, which could either be an inaccuracy of the drawing or a limitation of the preservation. The state of the specimen did not permit to clearly see the condition of the epichile. The combination of plant size, unjointed leaves, and deeply erose petals is consistent with the identification of this plant as O. brachystachys . The drawings of the flowers of O. brachystachys ( Fig. 1a View FIG ) and O. demissa by Hooker ( Fig. 1e View FIG ) are indistinguishable.

The exquisite drawing under O. demissa by King and Pantling (1898: pl. 10) shows a flower with lateral lobes of the lip drawn downwards, a distinct constriction of the mesochile, and very small epichile lobes. It appears intermediate between O. brachystachys with sub-quadratic lateral lobes and distinct constriction of the mesochile, and the O. parvula -morph (see below) with drawn down epichile lobes but little constriction of the mesochile. It is not clear which plant formed the basis of this drawing and, hence, the accuracy of the drawing could not be verified.

Oberonia gardneriana View in CoL is a synonym of O. brachystachys View in CoL . It was described with a bract more or less as long as the pedicelled ovary, oblong, blunt and denticulate petals ( petalis oblongis, obtusis, denticulatis), and a red lip. The lip was not further described and no size indications were provided. It was compared only to O. wightiana View in CoL (see above for differentiation). While the description is far from complete, that combination of characters is most compatible with O. brachystachys View in CoL amongst the species known from Sri Lanka ( Jayaweera, 1981; Fernando et al., 2003; de Vlas, 2019). Members of the section Scyllae ( O. bicornis Lindl. View in CoL [= O. tenuis Lindl. View in CoL : Geiger, 2019], O. claviloba Jayaw. View in CoL , O. dolabrata Jayaw. View in CoL , O. fornicata Jayaw. View in CoL , O. meegaskumburae Priyad., Wijew. & Kumar View in CoL , O. scyllae Lindl. View in CoL , O. walliesilvae Jayaw. View in CoL , O. weragamaensis Jayaw. View in CoL ) have pubescent edges of the petals. This section of Oberonia View in CoL is in need of critical assessment, which is, however, beyond the scope of this contribution. Oberonia forcipata Lind. View in CoL , O. truncata Lindl. View in CoL , O. wightiana View in CoL , and O. zeylanica Hook. View in CoL f. have linear lanceolate petals, O. longibracteata Lindl. View in CoL has bracts that are much longer than the pedicelled ovary, O. quadrilatera Jayaw. View in CoL has sessile flowers, and the petals of O. thwaitesii Hook. View in CoL f. are very similar to the ovate triangular sepals. Accordingly, with the available data and historical precedents, it is most likely that O. gardneriana View in CoL is conspecific with O. brachystachys View in CoL . Jayaweera (1981), who had seen the type, listed O. gardneriana View in CoL under O. recurva View in CoL , itself a synonym of O. brachystachys View in CoL .

The gathering of the type of O. gardneriana is ambiguous. Thwaites (1861) gave Gardner, in italics but no number, suggesting a gathering. He also gave the number C. P. 593, in roman font, a letter-number combination frequently seen with Thwaites material. As the only specimen at PDA could not be examined and PDA did not respond to inquiries, this matter remains to be fully resolved .

The typification of O. parvula presents some challenges. King and Pantling (1896) neither designated a particular type gathering, nor did they illustrate the species in the protologue itself. The likely original material ( Pantling 203) from Teesta valley, 1500 ft, is not precisely from the type locality Guru-bathan, 1500 ft., specified in the protologue, which is located in the northern most Teesta valley. Despite this minor mismatch, Pantling 203 is clearly original material (See Art. 9.4, Turland et al., 2018). Ansari and Balakrishnan (1990) inadvertently designated the CAL specimen as the lectotype (See Art. 9.3, Turland et al., 2018).

The illustrations of the species in King and Pantling (1898: pl. 6 B) with a drawing by R. Pantling, are excellent, certainly represent the original species concept, and clearly identify the species. Although some published drawings are highly inaccurate to misleading ( e.g., O. carpina Gilli : see Geiger, 2019), Pantling 203 ( K 000387743) matches the illustration by King and Pantling (1898) very well with the pointed lateral lobes and the acuminate falcate epichile lobes.

Oberonia parvula View in CoL ( Fig. 2a–d View FIG ) was described in the protologue from Bhutan [today India View in CoL , West Bengal], Guru-bathan [= Gorubathan, N-most end of Tista river], 1500 ft, and no gathering was specified. The lectotype was designated based on likely original material from Teesta valley. The species is typically considered a synonym of O. recurva View in CoL (Ansari & Balakrishnan, 1990; Rajbhandari, 2015; WCSP, 2020), but has been recognized as a distinct species by a number of authors ( Brühl, 1926; Mitra, 1958; Bose & Bhattacherjii, 1980; Naithani, 1990; Sakkar, 1995a,b; Bose et al., 1999; Lucksom, 2007; Raskoti, 2009). The distinguishing characters between the O. parvula View in CoL -morph and O. brachystachys View in CoL include: petals only with irregular outline in O. parvula View in CoL , distinctly to strongly erose in O. brachystachys View in CoL ; lateral lobes of lip with downwards expanding tips and entire margin in O. parvula View in CoL , quadratic with erose lateral margin in O. brachystachys View in CoL ; mesochile barely constricted in O. parvula View in CoL , strongly constricted in O. brachystachys View in CoL ; epichile lobes straight or curved towards midline with entire margin in O. parvula View in CoL , expanding laterally away from midline with strongly erose margin in O. brachystachys View in CoL . The very limited number of samples, the intermediate forms known e.g. as O. croftiana View in CoL (see below), the illustration under O. demissa View in CoL by King and Pantling (1898: pl. 10: see above), and the known extensive intraspecific variability in Oberonia species demonstrated by molecular phylogenetic studies ( Li et al., 2016; Geiger et al., 2020), however, suggests that O. parvula View in CoL is a mere morph of O. brachystachys View in CoL .

The O. parvula View in CoL -morph shares some floral characteristics with O. acaulis View in CoL , such as the drawnout tip of the lateral lobe. Those similarity may have been the reason to consider it a variety of O. myriantha Lindl. View in CoL , a synonym of O. acaulis Griff. View in CoL : O. myriantha var. parvula (King & Pantl.) Tang & Wang. Tang and Wang (1951) View in CoL based their assessment purely on vegetative characters, but even the jointed leaves of O. acaulis View in CoL do not agree with the unjointed leaves of O. brachystachys View in CoL . Additionally, O. acaulis View in CoL has much longer leaves even in small plants, the bract is serrated (not entire or slightly erose), the mesochile of the lip shows a distinct constriction, and the apical lobes diverge from the mid-line. The coloration of the flower typically shows a darker spot in the disc area not known from O. brachystachys View in CoL . Accordingly, O. parvula View in CoL is here synonymized under O. brachystachys View in CoL , while O. acaulis View in CoL is a distinct species. The same conclusion was reached by Seidenfaden (1968).

The specific epithets myriantha and acaulis were recently confused by Bunpha et al. (2019), along with several other misinterpretations about the taxonomy of Oberonia species. It is beyond the scope of this contribution to correct those problems.

The type material of O. croftiana presents some challenges. The protologue gave Sikkim-Bhutan frontier, on the banks of the Jaldakha river, 900 ft. as the type locality for Pantling 254. Pantling gatherings were not necessarily collected at a particular time, and may not have been from the exact same place, hence, do not constitute a gathering in the conventional sense: one species from a particular locality at a particular time (A. Schuiteman, pers. comm.). In the case of O. croftiana, Pantling 254 in W (W5951) and L (L0061772) were collected at Dikling at 2000 ft., some 20 km W of the border to Bhutan and approximately 50 km NW of the Jaldakha river, in February, 1897. Pantling 254 first-step lectotypes CAL0000000048 and CAL0000000049, and isolectotypes AMES 72805/HUH00101950, K000387742 and P00404879 were collected in Tropical Valley in October 1893. While the localities of all those specimens do not precisely match the indication in the protologue, they are considered here part of the lectotype series; it certainly is original material in the sense of Turland et al. (2018). CAL0000000048 was annotated as “Type” by Ansari in 1985. However, no specific sheet of the two at CAL was explicitly referred to in any publications, the mention of CAL as type repository only qualifies as a first-step lectotypification (See Art. 9.17, Ex. 14, Turland et al., 2018). We here explicitly designate CAL0000000048 as lectotype by second-step lectotypification.

Oberonia croftiana View in CoL ( Fig. 2e–h View FIG ) is a synonym of O. brachystachys View in CoL . The species has been given as a synonym of O. recurva View in CoL in the literature (Ansari & Balakrishnan, 1990; WCSP, 2020). It has been considered a correct name by some ( Brühl, 1926; Mitra, 1958; Bose & Bhattacherjii, 1980; Naithani, 1990; Sakkar, 1995a; Bose et al., 1999; Lucksom, 2007). It is notable, that the authors who consider both O. parvula View in CoL and O. croftiana View in CoL distinct are almost identical. We have not found any publication that considers O. parvula View in CoL with synonym of O. croftiana View in CoL as distinct from O. brachystachys View in CoL / recurva View in CoL . The shared characters between O. croftiana View in CoL and O. brachystachys View in CoL include the lateral lobes of the lip with erose margin and distally extended tip, the constriction of the mesochile, and the epichile lobes with erose margin. Lucksom (2007: fig. 163) illustrated a drawing under the name O. parvula View in CoL that shows an intermediate condition between the illustrations of O. parvula View in CoL and O. croftiana View in CoL , which lends support to the synonymy of the two taxa. Lucksom’s (2007: fig. 162) illustration of O. croftiana View in CoL shows a specimen with even more pronounced falcate epichile lobes. A drawing on the isolectotype (P00404879, Fig. 2g View FIG ) shows rather different interpretation of the flower: petals entire and not erose, lateral lobes of the lip, not downward sloping, and epichile lobes short and square, not elongated sub-falcate. It is a further example of how the same plant may be interpreted differently. A drawing and annotation of the flower on isolectotype (CAL0000000049) by Shakya in 1997 shows the lateral lobes expanding laterally without downturned tips and noted the epichile lobes are entire. Those differences compared to the drawings on the other isolectotypes and the drawing by King and Pantling (1898: pl. 6A) are a clear indication of intraspecific variability. The alternate explanation that the type gathering from Tropical Valley at CAL and P is composed of multiple, barely distinguishable species is too far-fetched.

Blatter and McCann (1931) compared O. lingmalensis View in CoL only to O. verticillata View in CoL from which it was distinguished by the flatter scape, the slightly erose linear bracts of variable length, long pedicelled ovary, and erose petals. The species has been considered a variety of O. recurva View in CoL by Santapau and Kapadia (1960, 1966), Sharma et al. (1984) and Naithani (1990). The characters given by Blatter and McCann (1931) are congruent with O. brachystachys View in CoL , specifically the vegetative description (no indication on jointed or unjointed leaves), the size of the flowers ( 2 mm), the shape of the bract, the erose petals, and the lip with erose lateral and epichile lobes. The species has never been illustrated. The holotype could not be examined and the repositories of the paratypes are unknown.

For O. brachyphylla, Blatter and McCann (1931) did not designate any type material. Their illustration was prepared from a live specimen, and the fate of that plant is unknown. The neotype designation by Santapau and Kapadia (1960) is in violation of Art. 9.19(a) of Shenzhen Code (Turland et al., 2018), because the illustration in the protologue constitutes original material (Art. 9.4b). Any original material must be considered for lectotypification before a neotype can be designated. Accordingly, the neotype designation by Santapau and Kapadia (1960) is here superseded by the lectotypification of O. brachyphylla through the illustration of the protologue (Blatter & McCann, 1931: pl. 2).

Oberonia brachyphylla ( Fig. 1k,l View FIG ) and O. brachystachys share the small vegetative size, the lack of jointed leaves, the small flowers ( 1.5 mm), the oval petals with erose margins, and the four-lobed lip with erose margins of the lateral lobes, entire constricted mesochile, and erose edges of the epichile lobes. The plant illustrated by Blatter and McCann (1931) is somewhat smaller than the types of the other names. Those size and slight shape differences of the leaves fall well within the known variability in other species, particularly O. rufilabris Lindl. (Geiger, pers. obs.). Blatter and McCann (1931) compared their species only to O. recurva and neglected O. brachystachys . They distinguished O. brachyphylla from O. recurva by the leaf shape (demonstrably highly variable), longer inflorescence (demonstrably highly variable in many species: Geiger, 2019), oblong sub-acute petals (no difference), lip much longer than the sepals (no difference), mid lobe square, bifid and incurved (no difference). Accordingly, the differentiation was based on lack of knowledge on intraspecific variability and outright errors, hence, O. brachyphylla is treated here as the synonym of O. brachystachys .

The alleged occurrence of O. brachystachys in China ( Seidenfaden, 1968) is questionable ( Chen et al., 2009: as O. recurva ). Given the past confusion of O. brachystachys and O. subligaculifera and their synonyms, Seidenfaden’s (1968) indication may be based on O. subligaculifera , which would match distributional patterns of the two species better.

Mitra (1958) listed Malaxis cordifolia Rchb.f. as the correct name for O. demissa . There are two M. cordifolia listed in WCSP (2020): Sm. in A.Rees, 1812, and the nom. illeg. by (Rolfe) Ames & C. Schweinf. in O. Ames, 1920. The former is considered a synonym of Liparis petiolata (D.Don) P.F.Hunt & Summerh. It is not clear what name Mitra (1958) was referring to. In any case, any potential Reichenbach name cannot threaten O. brachystachys , as Reichenbach’s orchid species names are all from after 1845 and placement in Oberonia would be after that.

AMES 72799 About AMES / HUH 00101944 is listed in AMES on-line catalogue as a possible isotype of O. brachystachys . However, given the specific collector and gathering numbers cited by Lindley (1838), which are not present on the AMES sheet, that specimen has no type standing at all.

The variability of O. brachystachys seems extensive, some may even suspect excess lumping of taxa. However, based on available material and information, it is impossible to form distinct groupings that would segregate the plants consistently with more than one character. For instance, the degree of serration of the petals is not correlated with the degree of serration of the lip, and neither is correlated with shape of the epichile lobes on the lip. The variability of the sac from a small depression ( Figs. 3k,n View FIG , 4b,e,f View FIG ) to distinct cavity ( Fig. 3c,d View FIG ) is surprising. All other flower attributes of Figure 4 View FIG with minute sac and the live plant of Figure 3c,d View FIG with distinct sac are identical. Ansari and Balakrishnan (1990: fig. 32g, 35g, 36g –i) seem to have noticed different extents of the sac formation as indicated by the shading in the central upper portion of the lip. The combination of absence of other confirming characters and evidence of variability by Ansari and Balakrishnan (1990) suggest as the simplest explanation that the sac condition is variable in O. b r a c h y s t a c h y s. To demonstrate distinct groupings, much more material would need to be collected, and the morphological data would ideally be supported with molecular techniques. The latter approach has demonstrated extensive intraspecific variability in Oberonia species ( Geiger et al., 2020).