Bulbophyllum bokodense M.N.Tamayo, Magtoto & R.Bustam., 2024

Tamayo, Maverick N., Magtoto, Liezel M., Penales, Patrick James F., Baquiran, Ethel Ruth A. & Bustamante, Rene Alfred Anton, 2024, Bulbophyllum bokodense (section Polymeres, Orchidaceae), a new species from Benguet Province, Luzon Island, Philippines, Phytotaxa 662 (2), pp. 187-194 : 188-191

Bulbophyllum bokodense M.N.Tamayo, Magtoto & R.Bustam. , sp. nov. ( Figs. 1 & 2 )

Section Polymeres

Type:— PHILIPPINES. Luzon Island, Cordillera Administrative Region, Benguet Province, Municipality of Bokod , Mt. Komkompol , Upper Agno River Basin Resource Reserve ( UARBRR), mossy forest, ca. 2200 m elevation, 18 July 2021, M. N. Tamayo 300 ( holotype: PNH!; isotype: NLUH!) .

Diagnosis:— Bulbophyllum bokodense is similar to B. rinkei Thoerle & W.A.Philipps (2019:190) endemic to New Guinea by having a seemingly 3-lobed labellum. However, B. bokodense is distinct by having a broader leaf ( 6–7 mm vs. 4–6 mm), a shorter inflorescence ( 4–5 cm vs. 4.2–7.5 cm), an acute petal apex (vs. rounded), a slightly canaliculate labellum (vs. non-canaliculate), glabrous auricles (vs. papillose), the mid lobe and apex of labellum devoid of concavity (vs. with concavity), and a longer stelidia (ca. 1 mm vs. ca. 0.5 mm).

Description:—Epiphytic herb. Rhizome creeping with roots below pseudobulbs. Pseudobulbs 1-leaved, pale to dark green, conoid or ovoid, shallowly angular when mature, glabrous, 8–9 mm × 4–5 mm, 1–2 mm apart. Leaves shortly petiolate, green, glabrous; petiole 0.5–1.0 mm long; leaf blade elliptic or lanceolate, slightly nodding, occasionally erect, 25–28 mm × 6–7 mm, 9-nerved, veins obscure, margin entire, apex acute or obtuse. Inflorescence solitary, scape arising from the base of pseudobulb, yellowish green or brownish, terete, erect to slightly arching, 4–5 cm long; floral bract greenish brown, acute, glabrous 2.0– 2.5 mm × 1.0– 1.5 mm. Pedicel greenish yellow, terete, glabrous, 5–6 mm × 0.5–0.7 mm. Ovary smooth, ridged, yellow, turning reddish towards apex, 3–3.2 mm × 1.5–2.0 mm. Flower yellow, non-scented; lateral sepal lanceolate, glabrous, yellow, with three reddish stripes at lower ½, 3-nerved, translucent at edge, margin entire, apex acute, 6.5–7.0 mm × 2.5–3.0 mm; dorsal sepal almost resembling the lateral sepal, glabrous, yellow, with three reddish stripes towards upper ¾, 3-nerved, margin entire, apex acute, 5.0– 6.5 mm × 2.5–3.0 mm. Petals smaller than sepals, imbricate, spathulate, glabrous, yellow, red punctate, with one reddish stripe, 1-nerved, 2.0– 2.7 mm × 1.0– 1.5 mm, margin entire, apex acute with a large reddish brown spot. Labellum seemingly 3-lobed, gradually folded downward over the abaxial side, thick, rigid, yellow with reddish spots especially at apex and auricles, narrowly to broadly lanceolate, recurved, 5-nerved, glabrous, devoid of any protuberances, 3.0– 3.3 mm × 1.5–2.0 mm, slightly canaliculate in the middle, with two shallow ridges at base, adnate to the column foot by white appendage; auricles crescent-shaped, erect, red, glabrous, ca. 2 mm × ca. 0.7 mm; mid lobe acute, yellowish with reddish spots, ca. 1 mm, apex red, rounded, obtuse or occasionally emarginate. Column ca. 1.5 mm long, smooth, cylindrical; stelidia narrowly triangular, obtuse, upcurved, apex obtuse or rounded, ca. 1 mm long; rostellum rounded, erect, slightly curved; stigma concave, deltoid to ovate; pollinia 4, ovoid, without stipe and viscidium; column foot ca. 2 mm long, slightly incurved. Fruits not seen.

Etymology:—The epithet refers to the Municipality of Bokod, Benguet Province, Philippines, where this new species was discovered.

Distribution and Habitat:—Only known from the mossy forest of Mt. Purgatory-Mangisi Traverse, UARBRR, Bokod, Benguet. Tree species in the area to which this new species was observed co-habiting include Ardisia spp. ( Primulaceae ), Lithocarpus spp. ( Fagaceae ), and Symplocos cochinchinensis ( Symplocaceae ).

Conservation Statu s:— Bulbophyllum bokodense is known only within the mossy forest of UARBRR. This area has not been fully assessed; as such, there is a chance that this species might be present within the vicinity of the protected area and neighboring forests, such as the south to south-eastern slope of Mt. Pulag Protected Landscape. Following IUCN criteria, we here provisionally assign a conservation status of data deficient (DD) pending thorough assessment ( IUCN Standards and Petitions Committee 2022).

Phenology:—Flowering in July.

Notes:— Bulbophyllum rinkei was incorrectly placed under sect. Monanthaparva Ridley (1896:269), but its morphology as having perforating pseudobulbs, single flowered inflorescences, and petals shorter than sepals, clearly places it as belonging to sect. Polymeres . The seemingly 3-lobed labellum of both B. bokodense and B. rinkei is a unique character for species under sect. Polymeres ; very few species possess this labellum morphology especially in Malesia. Moreover, Bulbophyllum bokodense is also similar to the widespread B. tenuifolium [ Blume (1825:316)] Lindl. (1830:50), but is distinct by having a shorter petiole ( 0.5–1 mm vs. 4–6 mm), a non-recurved median sepal (vs. recurved), spathulate petals (vs. obtuse), presence of auricles near the base of labellum (vs. absence), labellum slightly canaliculate (vs. non-canaliculate), and an upcurved stelidia (vs. downcurved).

In the Philippines, other species of Bulbophyllum closely resembling B. bokodense are B. gilvum J.J. Verm. & A.Lamb (1994:338) and B. pelseri Mansibang & R.Bustam. (2024: 4) ; however, B. bokodense is distinct from the former by having a longer inflorescence ( 4–5 cm vs. 2–3 cm), larger floral bracts (2.0– 2.5 mm vs. 1.0– 1.5 mm), spathulate petals (vs. obtuse), absence of minute papillae on petal margin (vs. presence), non-convex labellum (vs. convex), the labellum slightly canaliculate adaxially (vs. non-canaliculate), and absence of papillae on the abaxial surface of the labellum (vs. presence), and from the latter by having shorter dorsal sepals (5.0– 6.5 mm vs. 6.0– 7.5 mm), a seemingly 3-lobed labellum (vs. non-lobed), absence of grooves on abaxial surface of labellum (vs. presence), a shorter column (ca. 1.5 mm vs. 1.5–1.7 mm), and an upcurved stelidia (vs. slightly recurved). Additionally, B. bokodense superficially resembles B. spissum J.J. Verm. (1996:360) , a widespread species in Indonesia and Malaysia. However, Bulbophyllum bokodense is distinct by having shallowly angular pseudobulbs (vs. non-angular), spathulate petals (vs. obtriangular), a seemingly 3-lobed and glabrous labellum (vs. non-lobed and finely papillose), and absence of median ridge on the basal half of the labellum (vs. presence).

Figures

FIGURE 1. Bulbophyllum bokodense M.N.Tamayo, Magtoto, & R.Bustam.A. Habit of a flowering plant in situ. B. Flower (ventral view) showing abaxial surface of labellum. C. Flower (ventral view) showing the labellum surface including details of sepals and petals. Photos of the holotype (M.N. Tamayo 300) by Liezel M. Magtoto.

FIGURE 2. Bulbophyllum bokodense M.N.Tamayo, Magtoto, & R.Bustam. A. Flowering plant. B. Flower (ventral view) showing the surface of the labellum (labellum slightly pulled outwards) including details of sepals and petals. C. Flower (ventral view). D. Flower (lateral view) with sepals and petals removed exposing the column, stelidia, and labellum. E. Labellum (flattened, adaxial view). F. Labellum (flattened, abaxial view). G. Anther cap (adaxial view). H. Anther cap (abaxial view). Drawn from the holotype (M.N. Tamayo 300) by Maverick N. Tamayo.