Bulbophyllum pingnanense J.F. Liu, S.R. Lan & Y.C. Liang, 2016

Liu, Jiang-Feng, Lan, Si-Ren, He, Bi-Zhu & Liang, Yi-Chi, 2016, Bulbophyllum pingnanense (Orchidaceae, Epidendroideae, Dendrobiinae), a new species from Fujian, China, PhytoKeys 65, pp. 107-112 : 108-111

Bulbophyllum pingnanense J.F. Liu, S.R. Lan & Y.C. Liang sp. nov. Figs 1 , 2

Type.

China. Fujian: Pingnan County, Shuangxi Town, on rock along Yuanyan River , 800-900 m, 27°01'N, 119°05'E, 23 June 2013, J.F. Liu 201312 (holotype: FAFU!; isotype: NOCC!) .

Diagnosis.

Bulbophyllum pingnanense is similar to Bulbophyllum brevipedunculatum T.C. Hsu & S.W. Chung and Bulbophyllum albociliatum (T.S. Liu & H.Y. Su) K. Nackejima. It differs from Bulbophyllum brevipedunculatum by having a longer dorsal sepal with either an obtuse or an acute apex and longer white ciliate on margins; longer and lanceolate lateral sepals; and glabrous lip. It can be distinguished from Bulbophyllum albociliatum by its shorter inflorescence, a longer dorsal sepal with either an obtuse or an acute apex.

Description.

Epiphytic herb. Rhizome creeping, slender, 0.6-1 mm in diam. Pseudobulbs 0.6-2.5 cm apart on rhizome, obovate-elliptic, 0.5-1.7 cm, 3-6 mm in diam., with a terminal leaf. Leaf sessile; blade oblong to linear-oblong, 1.8-6.6 × 0.6-1.2 cm, apex obtuse to retuse. Scape arising from base of pseudobulb, ca. 1.1 cm, umbel 3-5 flowered; peduncle slender, ca. 0.6 mm in diam., with 3 or 4 sheaths; floral bracts triangular, 2-3 mm. Pedicel and ovary ca. 4 mm. Flowers orange red. Dorsal sepal concave, ovate, abaxially papillose, ca. 5 × 3 mm, margins long white ciliate, apex obtuse or acute; lateral sepals lanceolate, abaxially papillose, 10-12 × ca. 2 mm, slightly twisted near the base, with their upper and lower edges often loosely adhering, margins glabrous, apex acute. Petals ovate, 2.7-3.0 × 1.2-2.0 mm, margins long white ciliate, apex rounded. Lip recurved, ovate-triangular, ca. 3 mm, abaxially deeply grooved, base attached to end of column foot by a mobile joint. Column yellow, subterete, ca. 1-2 mm, with a distinct foot, ca. 1.0-2.5 mm, conspicuously winged; stelidia triangular, slender; anther cap subglobose; pollinia 4, in 2 pairs, without appendages.

Distribution and habitat.

Bulbophyllum pingnanense is so far only known within Pingnan, Fujian, China (Fig. 3 ). It is epiphytic on steep rock in the edge of evergreen coniferous and broad-leaved mixed forest, which is mainly composed of Castanopsis eyrei (Champ. ex Benth.) Hutch. ( Fagaceae ), Cunninghamia lanceolata (Lamb.) Hook. ( Taxodiaceae ). Other orchids, Amitostigma gracile (Bl.) Schltr., Pholidota cantonensis Rolfe, Cymbidium floribundum Lindl. and Pleione formosana Hayata, were found growing nearby this new species.

Phenology.

Flowering from June to July.

Conservation status.

Bulbophyllum pingnanense is known only from the type locality, and only one population of ca. 3000 individual plants was discovered in a small area of ca. 0.002 km2 during two years of botanical surveys. Based on the extent of occurrence estimated to be less than 100 km2 (CR B1) and the area of occupancy less than 10 km2 (CR B2), species existing at a single location (CR B1a + B2a), Bulbophyllum pingnanense is assigned a preliminary status of Critically Endangered (CR B1a + B2a) according to the IUCN Categories and Criteria ( IUCN 2012). In addition, the plants of Bulbophyllum are used as herbal medicine in the locality. It is possible that Bulbophyllum pingnanense might also be collected for using as herbal medicine. Therefore, immediate conservation strategy should be taken.

Etymology.

The species epithet refers to Pingnan County where this new species was found.

Taxonomic notes.

Several morphological characters, such as the dorsal sepal being much shorter than the lateral sepals, and the lateral sepals twisting and connected, indicate that this species belongs to sect. Cirrhopetalum . Bulbophyllum pingnanense is closely related to Bulbophyllum brevipedunculatum , but it can be distinguished by having a longer (ca. 5 mm vs. ca. 3.5 mm) dorsal sepal with either an obtuse or an acute (vs. rounded) apex and longer white ciliate (vs. short white ciliate) on margins, longer (10-12 mm vs. 5-7 mm) and lanceolate (vs. near rectangular) lateral sepals, glabrous (vs. adaxially papillose) lip. In addition, the two species had different flowering seasons that never overlapped (June-July vs. March-April), and the nearest distance between them is ca. 370 km, separated by the sea (Fig. 3 ). The new species is also closely related to Bulbophyllum albociliatum , but it can be distinguished by having a shorter (ca. 1.1 cm vs. 4-6 cm) inflorescence, and a longer (ca. 5 mm vs. 3-4 mm) dorsal sepal with either an obtuse or an acute (vs. rounded) apex; the nearest distance between the two species is ca. 350 km, separated by the sea (Fig. 3 ).

Figures

Figure 1. Bulbophyllum pingnanense sp. nov. A plant B flower C dorsal sepal D lateral sepal E petal F lip G pollinia and anther cap H lip, column, pedicel and ovary, side view (Drawn from the holotype by Bi-Dan Lai).

Figure 2. Bulbophyllum pingnanense J. F. Liu, S. R. Lan & Y. C. Liang. A habitat and habit B-D flower E dorsal sepal F lateral sepal G petal H lip I lip, column, pedicel and ovary, side view J pollinia and anther cap.

Figure 3. Distribution of Bulbophyllum pingnanense, Bulbophyllum brevipedunculatum and Bulbophyllum albociliatum.