Jaap J. Vermeulen, André Schuiteman & Eduard F. de Vogel
Bulbophyllum katjae Photo: J.J. Vermeulen
Bulbophyllum najae Photo: P. Jongejan
Bulbophyllum palleucum Photo: E.F. de Vogel
Bulbophyllum stolleanum Photo: P. Jongejan
Bulbophyllum yumtei Photo: A. Schuiteman
Bulbophyllum gunteri Photo: A. Sieder
Bulbophyllum brachygnomon Photo: J. Meijvogel
Bulbophyllum campylopetalum Photo: P. Jongejan
Bulbophyllum schizodon Photo: A. Schuiteman
Summary: The new section Lasiogaster is proposed to accommodate two species of Bulbophyllum from Sulawesi and New Guinea. Fifteen new species of Bulbophyllum of sections Brachypus, Lasiogaster, Papulipetalum and Peltopus from New Guinea are described and illustrated. According to our list of accepted species this brings the total number in the genus to 2008. Bulbophyllum stolleanum is neotypified.
Bulbophyllum chionanthum sp. nov. (sect. Brachypus) shares with B. tetratropis the narrow sepals (ratio length/width of lateral sepals 2.5 or more), combined with an ellipticto obovate median sepal. It differs from B. tetratropis by the smaller lip (2.8 - 3.0 mm long, versus 5.0 - 5.5 mm long), and by the glabrous (not ciliolate) lip margins.
Bulbophyllum katjae sp. nov. (sect. Brachypus) is most similar to B. cerinum Schltr.; diagnostic is the absence of a distinct ridge along each side of the column that follows the lower margin of the petals. Additional differences are the length of the petals (3.9 - 5.5 mm long versus 5.5 - 7.5 mm in B. cerinum) and the length of the lip (3.9 - 4.8 mm versus 4.8 - 7.2 mm in B. cerinum). The sepals are less distinctly thickened towards the apex, and more sharply acute in B. katjae.
Plants with short and wide lateral sepals may resemble B. yumtei, below, which differs by the obovate-oblong (versus triangular) petals. The lip structure of B. yumtei is also different, see notes under that species.
Bulbophyllum najae sp. nov. (sect. Brachypus) shares the basally adherent or adnate, glossy sepals with B. maxillarioides Schltr., and B. rhomboglossum Schltr., both from sect. Brachypus. It differs from the first by its glabrous (not ciliolate) lip margins, from the second by the wider sepals (median sepal 8.5 - 11.6 mm wiede, versus 5.0 - 6.0 mm wide; lateral sepals 7.0 - 11.0 mm wiede, versus 5.2 - 6.2 mm wide).
Within section Brachypus, Bulbophyllum palleucum sp. nov. shares with B. galactanthum Schltr., B. versteegii J.J.Sm., and B. stolleanum Schltr. (see below), the set: narrow sepals (ratio length/width of lateral sepals 2.5 or more), median sepal ovate to triangular, and lateral sepals narrow (3 - 5.8 mm wiede). B. palleucum differs from all three by the wide petals (1.8 - 2 mm wide, versus 0.5 - 0.9 mm wiede).
Within section Brachypus, Bulbophyllum schistocodon sp. nov. is characterized by the adherence of the median sepal to the laterals along approximately one third of its length. Only B. ustusfortiter J.J.Verm., of the same section, has similar flowers, but here the median sepal adheres to the laterals almost from base to apex, leaving only a small lumen at the apex of the flower.
We cannot trace any extant type material of Bulbophyllum stolleanum Schltr. (sect. Brachypus), for which reason we indicate and illustrate a neotype.
Winthin section Brachypus, Bulbophyllum tetratropis sp. nov. is uniquely characterized by the presence of four ridges on the adaxial side of the lip. It shares with B. chionanthum, above, the narrow sepals (ratio length/width of lateral sepals 2.5 or more), combined with an elliptic to obovate median sepal; the differences between the two are given under the latter.
Bulbophyllum yumtei sp. nov. is uniquely characterized within section Brachypus by the high ridges on the adaxial side of the lip. As a result, the true lip margins run over the abaxial face of the lip, of which the true abaxial side is only the area in between the lip margins. Next to this, B. yumtei fits in a small group of species within the section with free sepals and the index of the lateral sepals 2.5 or less. Most similar in this group is B. katjae, above, which has triangular, rather than obovate-oblong petals. B. galactanthum Schltr., and B. hans-meyeri J.J.Wood are the other two species in this group; they have shorter sepals (the median 7 - 13 mm long). B. maxillarioides Schltr. is superficially similar to B. yumtei, but has partially connate lateral sepals and a lip lacking high ridges.
Bulbophyllum gunteri sp. nov. (sect. Brachypus?) is most similar to B. phaeoglossum Schltr. and B. pterodon, below; it differs from the first by having ciliolate lip margins. The differences between B. gunteri and B. pterodon are given below.
Bulbophyllum pterodon sp. nov. (sect. Brachypus?) is most similar to B. phaeoglossum Schltr. and B. gunteri, above; it differs from both by having petals more than half as long as the median sepal, and by the presence of a distinct, obtuse wing along the upper margins of the stelidia. It also differs from B. phaeoglossum by its ciliolate lip margin.
Bulbophyllum trutiniferum sp. nov. (sect. Brachypus?) is similar to B. gunteri, and B. pterodon, above, and B. phaeoglossum Schltr.; it differs from all three by the partially adherent sepals and the three-lobed lip.
Bulbophyllum brachygnomon sp. nov. (sect. Brachypus?) is similar to B. variculosum J.J.Verm.; differs by deltoid stelidia, with a rounded to minutely acuminate apex (versus stelidia narrowly triangular, long acuminate or spathulate at the apex).
Section Lasiogaster sect. nov. is most similar to section Monanthaparva Ridl. but differs by the coarsely papillose adaxial lip surface, with papillae arranged in transverse rows.
Bulbophyllum lissogaster sp. nov. differs from B. lasiogaster J.J.Verm. & P.O'Byrne, from Sulawesi, by its glabrous petals, and the glabrous face of the column.
According to the label (of Woods 365?), the pseudobulbs are growing in 'clustered lines'. The available fragment of the plant has a few root remants growing backwards along the rhizome, but the mode of growing, with creeping or patent rhizomes, cannot be determined with certainty.
Bulbophyllum campylopetalum sp. nov. (sect. Papulipetalum) shares with B. brachychilum Schltr. the partly papillose ridges on the adaxial side of the lip. B. campylopetalum differs by its downwards-falcate, elliptic to obovate petals (versus straight, ovate to triangular petals), as well as by having more prostrate, more distinctly angular pseudobulbs.
Bulbophyllum schizodon sp. nov. (sect. Papulipetalum) is most similar to B. arsoanum J.J.Sm., with which it shares the presence of a tooth below the base of the stigma. In B. schizodon this tooth is deeply divided itno two (in B. arsoanum in consists of a single, transverse ridge). Next to this, B. schizodon has larger petals (6.0 - 6.6 mm long, versus 3.0 - 4.0 mm long), and a lip which is widest in the apical half (versus lip widest in the basal half).
In the revision of section Peltopus (Vermeulen, 1993: 145), Bulbophyllum hapalocodon sp. nov. keys out next to B. scutiferum J.J.Verm. (l.c.: 173); it differs from B. scutiferum by its much longer sepals (median sepal c. 24 mm long, versus 4.5 - 11.5 mm long), which are acuminate-caudate (versus acute), and by the distinctly protruding lower margin of the stigma.
Published in Malesian Orchid Journal Vol. 21 (2018): 31 - 68