Oberonia heliophila Rchb.f.

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 : 194-196

Oberonia heliophila Rchb.f. — Fig. 8 , 9

Oberonia heliophila Rchb.f. (1878) 56. — Lectotype (designated by Kores 1989): U.S. Exploring Expedition s.n. (lecto W37726), Fiji, Vanua Levu, Mountains of Mathuata Province. Paralectotypes: U.S. Exploring Expedition s.n. (W Reichenbach 37727 W68809), Samoa, Ovalau; U.S. Exploring Expedition s.n. ( US 37773) Samoa; Seemann 587 ( AMES 00101970 , BM000088475 , K 00079501,K-L s.n., P [?: see notes], W 37711), [ Fiji,] Viti Levu, Tailevu Province, Namara; Graeffe s.n. (repository unknown), Upolu, Samoa; Whitmee s.n. ( BM 000082108 , K 00079502), [ Samoa,] Sawai’i.

Oberonia asperula J.J.Sm. (1908) 30. — Syntypes: Versteeg 1322 (BO, L0061733), [ Indonesia,] S. New Guinea (L type label), Noord River , at foot of Nepenthes Hill (protologue), on trees in Metroxylon swamps ( Smith 1909), syn. nov.

Oberonia rivularis Schltr. in K.Schum. & Lauterb. (1905) 115. — Syntypes: Schlechter 13801 (B, lost,K 00079467 [no flowers]),[ Papua New Guinea,] at the riverboard of the Nuru mid-section, ~ 200 m, syn. nov.

Oberonia (Sect. Scytoxiphium) inversiflora J.J.Sm. (1912) 487 (‘ inversiflorum ’). — Type: Lorentz Exp. 1909 , Rachmat live plant number 431 (syn BO Bogor cult.). Exp. s.n. (possible syn L 0061748), s. coll. (possible syn BO 0071552,L 0727884,U.1459111,U.1459112), without locality ‘Cult in Hort. Bog.’signed by J.J. Smith, Dutch New Guinea, hills near Alkmaar, syn. nov.

Oberonia hosokawai Fukuy. in Hosok. (1941) 290 ( ‘ hosokawae ’). — Syntypes: Hosokawa 9599 (syn AMES 67290 /Harvard Barcode 114495, L0061745,MICH 1115255, TAI 118740 ,US 2036596), Micronesia,Ponape, Mount Asama-san, 500–800 m (protologue), US label 500– 200 m, syn.nov .

Notes — The types of O. heliophila were treated in detail by Kores (1989). His cited ‘isolectotype’ AMES 3034 is not recorded in the AMES herbarium catalogue. AMES 3034 was cited for multiple localities, which suggest that multiple specimens from several different gatherings were mounted on one herbarium sheet. Given the large size of the plant, an alternate interpretation is that AMES 3034 does not refer to a specimen registration number, but an accession number of an entire collection. A specimen of Seemann 587 at P according to Kores (1989) could not be found in the P collection or catalogue.

Oberonia asperula is a synonym of O. heliophila . The shared characters ( Fig. 8e ) include the very large plant size in the genus, the acaulescent habit and long acuminate, fleshy leaves. The flower with the thick trapezoidal lip, the narrow oblong petals, the broad, reflexed and pubescent sepals, the pubescent pedicelled ovary, the broad strongly double incised bracts, the very short column, and the green coloration of the flower.

Oberonia rivularis is a clear synonym of O. heliophila after examining syntype material of both taxa. The large size of the plant, the flowers in well-separated whorls, the green lip with tan remaining tepals, the broad ovate-acuminate lip with serrated margins all support the synonymy ( Fig. 8c ). Schlechter in Schumann & Lauterbach (1905) noted that O. rivularis is the smallest of the section Scytoxiphium Schltr. in New Guinea, a statement copied by O’Byrne (1994). It is unclear what may have led Schlechter to such a statement because in terms of vegetative size, it is amongst the largest species.

The possible syntypes of O. inversiflora in L are difficult to as- sess. Only one specimen identified by J.J. Smith as O. inversiflora (L 1513897) can positively be excluded, because of a collection number mismatch (C 278 on sheet, Rachmat 431 in protologue). The other specimens can neither be confirmed nor excluded. The 1912 and 1913 Soeda Sublimaat [= Soda sublimate = mercury chloride] dates are pest treatment dates, and not collection dates.

Oberonia inversiflora shares multiple characters with O. heliophila ( Fig. 8d ). It is an unusually large plant for the genus with leaves to 40 cm long and has a very compressed vegetative axis. The flowers share the deeply incised bract, the very hairy pedicelled ovary, the few hairs on the back of the sepals, the straw to pale brown sepals, the thick, light green lip with small triangular side lobes and broad ovate apical lobes. There are no characters that could support a separate status. The illustration of O. inversiflora by Smith ( Fig. 8d ) shows somewhat wider petals. Those fall within the range of variability found by examination of multiple flowers by SEM ( Fig. 9 ), accordingly, are taxonomically meaningless. Oberonia heliophila is known from Papua New Guinea. Accordingly, the two species are synonyms.

The spelling of the species introduced as O. hosokawae [sic] has to be corrected. The species was named in honour of the collector of the plant Takahide Hosokawa, a man. In accordance with ICN (2018) Art. 60.8a, the spelling of the name is here corrected from O. hosokawae to O. hosokawai . There are an additional eight species epithets that need to be corrected as well: Carpesium hosokawae Kitam. ( Asteraceae ), Glochidion hosokawae Fosberg ( Phyllanthaceae ), Pandanus hosokawae Kaneh. ( Pandanaceae ), Psychotria hosokawae Fosberg ( Rubiaceae ), Eria hosokawae A.D.Hawkes & A.H.Heller , Microtatorchis hosokawae Fukuy. (now Taeniophyllum hosokawae (Fukuy.) L.O.Williams ), Habenaria hosokawae Fukuy. , Moerenhoutia hosokawae (Fukuy.) Tuyama (all Orchidaceae ). There is one properly formed name, Cirsium hosokawai Kitam. ( Asteraceae ). The type repository for O. hosokawai was not specified in the protologue, for which reasons all specimens of the type gathering are syntypes.

Oberonia hosokawai is a synonym of O. heliophila . The shared characters include the very large size of the plant with slightly falcate leaves in an acaulescent fan, the broad floral bract with serrated margin, the narrow acuminate petals, the thickened lip with broad ovate basiochile, short and thick column, hairs on fruit (MICH 1115255: Fig. 8b ). Further supporting evidence includes that Hawkes (1952) placed the species in the section Scytoxyphium , to which O. heliophila belongs.

Figures

Fig. 8 Oberonia heliophila. a. Flowers from lectotype U.S. Exploring Expedition s.n. W37726 of O. heliophila; b. flowers on MICH syntype of O. hosokawai; c. original figures of O. rivularis from Schlechter (1923); d. drawing of flower of O. inversiflora by J.J. Smith (from Schuiteman & De Vogel 2006); e. illustration of flower of O. asperula from Smith (1909). — Scale bars: a–b = 1 mm.

Fig. 9 Oberonia heliophila SEM images. a. Schuiteman 90/555 L23197 from Papua New Guinea; b–c. Harris 1514 L19688 from Papua New Guinea; d. de Vogel s.n. L20059 from New Guinea; e. Mulder s.n. L22448 from Fiji; f. Hunt 2226 K28510 from the Solomon Islands. — Scale bar = 1 mm.