Coelogyne victoria-reginae Q.Liu & S.S.Zhou, 2018

Zhou, Shi-Shun, Tan, Yun-Hong, Jin, Xiao-Hua, Maung, Kyaw Win, Myint Zyaw,, Li, Ren, Quan, Rui-Chang & Liu, Qiang, 2018, Coelogyne victoria-reginae (Orchidaceae, Epidendroideae, Arethuseae), a new species from Chin State, Myanmar, PhytoKeys 98, pp. 125-133 : 125

Coelogyne victoria-reginae Q.Liu & S.S.Zhou sp. nov. Figs 1 , 2

Diagnosis.

Coelogyne victoria-reginae is closely related to C. prolifera by having the elliptic mid-lobe with two lamellae terminating at 2/3 on to mid-lobe, ovate or oblong lateral lobes. However, the new species can be distinguished from the latter by the ovoid pseudobulb and 1.1-1.4 cm apart on rhizome, flower brownish-red, lateral sepals (10-11 × 5.5-6.0 mm) significantly larger than dorsal sepal (7.0-8.0 × 4.5-5.0 mm).

Type.

MYANMAR. Chin State. Natma Taung (Mt. Victoria) National Park , subtropical evergreen broad-leaved forest, 2400-2600 m, epiphytic on the upper trunk, 1 May 2017, Qiang Liu, M17-18 (holotype, HITBC!, isotypes, RAF!) .

Description.

Epiphytic, rhizome creeping, rigid, 3.5-4.5 mm in diameter, densely covered with leathery scaly sheaths, with rather short internodes. Pseudobulbs 1.1-1.4 cm apart on rhizome, globose or ovoid-oblong 3.1-4.0 × 1.0-1.5 cm. Leaves two on each pseudobulb, terminal, oblong lanceolate, coriaceous, 6.5-8.3 × 2.4-3.1 cm, apex acuminate; petiole 1.0-1.7 cm. Inflorescence arising from top of mature pseudobulbs, up to 21.5-32.3 cm long, 4-6-flowered, far longer than leaves, with many persistent distichous sterile bracts just below rachis and several closely spaced distichous sterile bracts at apex of the rachis. Rachis extending and producing annual sets of imbricate bracts and flowers. Floral bracts lanceolate, almost deciduous at anthesis, ca. 1.2 cm; pedicel and ovary 8.0-10.0 mm. Flowers brownish-red, dorsal sepal triangular-ovate, 7.0-8.0 × 4.5-5.0 mm, acuminate; lateral sepals similar to dorsal sepal,10.0-11.0 × 5.5-6.0 mm. Petals narrowly linear, acuminate, 9.0-10.0 × 1.0 mm; lip 3-lobed, subovate, 10.0-11.0 × 7.0-8.0 mm, callus with 2 conspicuous longitudinal lamellae extending from base of mid-lobe; lateral lobes erect, ovate, 5.0 × 3.0 mm; mid-lobe nearly elliptic, reflexed, ca. 6.0 × 5.0 mm, margin undulate, apex emarginate; column ca. 6.0 mm, apex winged with serration; anther cap coniform; pollinia four, semi-orbicular.

Etymology.

The new species is named after Victoria Mountain region, NatmaTaung National Park, Chin State, South-western Myanmar, where it was discovered in a vast area of mountain forest.

Phenology.

Flowering occurs in April and May.

Distribution and habitat.

Coelogyne victoria-reginae is only known from the type locality. It grows as an epiphyte on tree trunks in subtropical evergreen broad-leaved forest, which is dominated by Lithocarpus xylocarpus (Kurz) Markg. ( Fagaceae ).

Conservation status.

Coelogyne victoria-reginae was collected in the Victoria Mountain, Natma Taung National Park, Chin State, South-western Myanmar. However, only one population, consisting of approximately100 individuals, has been discovered so far in the National Park. Although other populations may be found with further investigation because the area is legally protected under the management of the Myanmar Forest Department, the number of mature individuals of the subpopulation may be less than 250 on account of similar habitat. Thus, the species is here assigned a preliminary status of EN C2a [i]according to the guidelines for using the IUCN Red List Categories and Criteria ( IUCN Standards and Petitions Subcommittee 2017).

Key to Coelogyne sect. Proliferae

1	Lip without lamellae, lateral lobes semi-orbicular in size	2
-	Lip with 2 lamellae, lateral lobes ovate or oblong	3
2	Flower brownish-red and lip white with a black apex, labellum large (15.0 × 9.0 mm), mid-lobe rotund	C. ecarinata
-	Flower pale yellow-green, labellum small (6.5 × 6.0), mid-lobe semi- elliptic	C. ustulata
3	Mid-lobe orbicular or sub-quadrate, with 2 lamellae faint near base of mid-lobe	C. schultesii
-	Mid-lobe nearly elliptic, with 2 lamellae terminating at 2/3 on to mid-lobe	4
4	Pseudobulb ovoid and 1.1-1.4 cm apart on rhizome, flower brownish-red, lateral sepals (10-11 × 5.5-6.0 mm) significantly larger than dorsal sepal (7.0-8.0 × 4.5-5.0 mm)	C. victoria-reginae
-	Pseudobulb narrowly ovoid-oblong and 2.5-4.0 cm apart on rhizome, flower green or yellow green, lateral sepals (3.0-3.6 × 1.2 mm) equal or smaller than dorsal sepal (3.0-4.0 × 3.0 mm) in size	C. prolifera

Figures

Figure 1. Coelogyne victoria-reginae. A Plant B Inflorescence C Lateral view of labellum D Pollinarium E Abaxial and adaxial anther cap F Sepals and petals G Front view of flower H Front and lateral view of column. All from the type collection (Qiang Liu, M 17 - 18) and drawn by Lan Yan.

Figure 2. Coelogyne victoria-reginae. A Habitat B Plant C Inflorescence D Flower E Lateral view of labellum F Front view of labellum G Front and lateral view of column H Abaxial and adaxial anther cap. I. Pollinarium (Photographed by Q. Liu)