Oberonia costeriana J.J.Sm.

Geiger, D. L., 2019, Studies on Oberonia 5 (Orchidaceae: Malaxideae). Twenty-four new synonyms, and a corrected spelling, Blumea 64 (2), pp. 123-139 : 127-128

Oberonia costeriana J.J.Sm. — Fig. 4

Oberonia costeriana J.J.Sm. (1905) 244. — Type: Blume s.n. (syn L 0061737),[ Indonesia, Java,] Mt Gede , at the water fall,parasitic; FW Junghuhn s.n. (syn L 0063834); unknown collector s.n. (syn), Indonesia, Java, Buitenzorg [= Bogor], Bobodjong; De Monchy s.n., Krawang; J.J. Smith s.n. (syn), [ Indonesia,] Pekalongan, Djolotigo; also [ Indonesia,] Sumatra .

Oberonia elmeri Ames (1912) 1564. — Type: ADE Elmer 8434 (syn AMES 12905 /barcode 00101962), Philippines, Benguet, syn. nov.

Oberonia obesa Ames (1915) 76. — Type: M. Vanoverbergh 407 (syn AMES 16637 /barcode 00102011,AMES 14194/barcode 00102010),[ Philippines,] Luzon , Bontoc Sub-province, syn. nov.

Oberonia kinabaluensis Ames & C.Schweinf. (in Ames 1920) 81, pl. 89, f. I, 1. — Type: Clemens J. 329 (syn AMES 16985 /barcode 00101974), [ Malaysia, Sabah,] Kiau .

Oberonia gigantea Fukuy. (1935) 295. — Type: N. Fukuyama 4543 (holo KPM-NA 0105567 ), Formosa [= Taiwan], Haihoku Prefecture , Shooagyokusan [= Syoagyokusan], Mountain broad-leaf forest, syn. nov.

Notes — Oberonia elmeri is here synonymised under O. costeriana . It differs allegedly by unspecified characters of the lip, the petals, and the colour of the flower. However, the habit of the plant on the type sheet and drawings of the flowers are identical to O. costeriana ( Fig. 4a–b ).

Oberonia kinabaluensis is here recognised as a synonym of O. costeriana , in agreement with O’Byrne & Gokusing (2017). The main difference of O. kinabaluensis and O. costeriana is the mid-lobe of the lip and the brown vs salmon colour ( Ames 1920). The difference in colour is well within the usual colour spectrum in Oberonia . The mid-lobe shares the diagnostic apical incisions of the lateral lobes, but appears to be narrowing towards the base. Topotypical material illustrated by Wood et al. (1993: pl. 64A) shows the shape of the lateral lobes typical of O. costeriana ( Fig. 4a, d ). It is quite possible that the drawing of that minute flower is inaccurate with respect to this detail (see also O. punctata / caprina below). Sympatric occurrence of two almost indistinguishable species is rather unlikely and postulating the extinction of O. kinabaluensis and simultaneous range extension of the almost identical O. costeriana is equally far-fetched. The cited differences in leaf morphology can easily explained by plants of different sizes or levels of maturity.

Oberonia obesa is here considered a synonym of O. costeriana . The differences in lip shape are rather small ( Fig. 4a, c ), and differences stated in the protologue in the leaf arrangement are due to some leaves being broken at the abscission plane and overlap the others for that reason alone. The other floral and vegetative characters all agree very well with O. costeriana , specifically the narrow lanceolate floral bracts. The identification of the type as O. costeriana has been previously noted on one of the type sheets.

Oberonia gigantea was initially suspected to be a synonym of O. costeriana based on matching illustrations in the secondary literature ( Lin 1987, Lin & Wang 2014, Su 2000). The original description noting the lip with the serrated, triangular lateral lobes and the small bilobed epichile as well as the type sheet confirmed the initial assessment. No disconfirming details could be discerned. Even the phenology data match (Geiger unpubl. data). Oberonia gigantea was used as a local name for O. costeriana from Taiwan.

Whether O. pygmaea Bunpha, H.A.Pedersen & Sridith (2014) is yet a further synonym of O. costeriana remains to be fully evaluated. The cited difference in the shape of the petals – linear-oblong in O. pygmaea vs oblanceolate in O. costeriana – cannot be confirmed; they are identical in specimens identified with either of the two names. The presence/absence of column wings is not evident from the illustrations. The expression of column wings can be variable within well-known species such as O. cavaleriei Finet (1908) (Geiger pers. obs. by SEM). The indistinct apical incision of the lateral lobe on a single small specimen is a rather dubious character.

Borrowing from statistics, for differences to be significant based on small sample size, the amount of differences must be large.

Figures

Fig. 4 a. Oberonia costeriana J.J.Sm.: illustration of the species by J.J. Smith, from Schuiteman & De Vogel (2006); b. drawing of O. elmeri from syntype AMES 12905/barcode 00101962 ADE Elmer 8434; c. drawing of the lip on type sheet of O. obesa (AMES 14194/barcode 00102010); d. drawing of Oberonia kinabaluensis from protologue.