Oberonia brunoniana Wight

Geiger, D. L., 2020, Studies in Oberonia 8 (Orchidaceae: Malaxideae). Additional 24 new synonyms, a corrected spelling, and other nomenclatural matters, Blumea 65 (3), pp. 188-203 : 191-192

Oberonia brunoniana Wight — Fig. 4

Oberonia brunoniana Wight (1851) 3, pl. 1622. — Lectotype (designated by Geiger 2019): Wight s.n. (lecto K 000387708), India, Coimbatore,Iyamally Hills, Mount Agamullu. Wight 2914 (paralecto K 000387707), Mount Paulghautcherry.

Oberonia wallichii Hooker (1888) 681. — Syntype: De Silva s.n. (repository unknown), [ India,] Silhet, syn. nov.

Oberonia saintberchmansii Kad.V.George & J.Mathew in Kad.V. George et al. (2019) 110, f. 1 (‘ saint-berchmansii ’). — Type: K. V. George & S. Antony 0126 (holo RHK;iso MSSRF), [ India,] Kerala, Idukki District,way to Nedukandam, Cardomom Hills , 3rd mile,alt. 1310 m, Jan. 2014, syn. nov .

Notes — The repository of the type for Oberonia wallichii is unknown. Specimens in K, K 000387713 Wallich 1948, and K 000387690 s. coll. are not from the type locality nor by the indicated collector, thus they do not seem to be types. A specimen, Lobb s.n. K s.n., from Khasiya Hills identified by Lindley as O. lindleyana (= O. brunoniana ) was identified by Hooker as O. wallichii , hence, constitutes an ideotype ( Fernald 1939). The associated drawing of the flower on the ideotype shows a typical O. brunoniana morphology.

This species has been overlooked and confused. For instance, Ansari & Balakrishnan (1990) in their monograph of Indian Oberonia , did not mention O. wallichii at all. The species was distinguished by Hooker (1888) by the smaller flower of 1/ 20 inch = 1.25 mm, which would be on the smaller side of any known Oberonia species, and would be extremely small for species in Ansari & Balakrishnan’s (1990) Section III. Those small-flowered specimens from Khasia in NE India were contrasted to the more typical larger-flowered ‘peninsular’ O. brunoniana s.str., i.e., those of SW India. It is interesting to note that the alleged smaller flower size has been repeated by reference to Hooker (1888), but has not been independently confirmed. The flower size seems to vary along a north-south gradient. The dimensions for O. saintberchmansii from Karnataka (N9°, see below) are 3.5 mm, the flower from Myosore (N12°) shown in Fig. 4d measures 2.4 mm, while specimens from Mumbai (N19°) were indicated as <2 mm in size ( Santapau & Kapadia 1960), and Hooker’s (1888) indication of 1.25 mm from Khasia (N24°).Accordingly, a latitudinal size gradient becomes evident. Without either a clear geographic break, or a distinctly bimodal size distribution, once specimens are sampled across the geographic range, no taxonomic separation seems justifiable for now. The observed differences appear to be ecophenotypical variation.

In the absence of any distinguishing characters, and the contradictory identifications of the same plant with various synonyms of O. brunoniana , O. wallichii is a further synonym of O. brunoniana .

Oberonia saintberchmansii is a clear synonym of O. brunoniana . The shared characters include the lip with broad lateral lobes, two relatively small epichile lobes, a well-defined smooth disc, narrow petals, overall fan-shaped vegetative habit of the plant. Oberonia brunoniana is well-known from Kerala (e.g., Ansari & Balakrishnan 1990), the type locality of O. saintberchmansii . There is no variant character of any kind. George et al. (2019) compared their new species only to O. falconeri , a species outside of Section III of Ansari & Balakrishnan (1990) to which O. brunoniana and allied species belong. In fact, George et al. (2019) did not even cite Ansari & Balakrishnan (1990), a key work on Oberonia of India. Schuiteman (pers. comm.) has indicated the synonymy previously. Additional synonyms of O. brunoniana were recently discussed by Geiger (2019).

Figures

Fig. 4 Oberonia brunoniana. a. Illustrations of the flowers of O. brunoniana from Wight (1851); b. illustration of O. saintberchmanii from George et al. (2019); c. drawing of the flower on lectotype of O. brunoniana (from http://specimens.kew.org/herbarium/K000387708); d. SEM image of flower. Barnes 2098 K24122, Mysore, India. — Scale bar = 1 mm.