Liparis napoensis L.Li, H.F.Yan & S.J.Li, 2019

Li, Lin, Chung, Shih-Wen, Li, Bo, Zeng, Song-Jun, Yan, Hai-Fei & Li, Shi-Jin, 2019, Liparis napoensis (Orchidaceae), a new species from Guangxi, China, PhytoKeys 119, pp. 31-37 : 33-34

Liparis napoensis L.Li, H.F.Yan & S.J.Li sp. nov. Figures 1 , 2

Type.

CHINA. Guangxi Zhuang Autonomous Region, Baise City, Napo County, Yongning Village, Jinlongyan Cave, lithophytic on moss in monsoon evergreen broad-leaved forest, alt. 830 m, 31 May 2012, L. Li 1001, (holotype, IBSC!).

Diagnosis.

Liparis napoensis differs from its closest allies: L. viridiflora and L. somae in the clustered ovoid-cylindrical or narrowly pyriform pseudobulbs, narrowly oblong-falcate petals; a flabellate-quadrate lip with a distinctly concave base, an emarginate apex and erose margins; a conspicuously arcuate column with a pair of wedge-shaped wings.

Description.

Lithophytic herbs. Pseudobulbs clustered, ovoid-cylindrical or narrowly pyriform, 5-10 cm × 5-8 mm, attenuate toward apex, base covered with 3-4 fibrous remnant sheaths. Leaves 2, terminal, blade oblanceolate or oblong-spatulate, thin coriaceous, base contracted into a very short petiole less than 1 cm or subsessile, apex acute and minutely apiculate, 7 –12× 1.5-2 cm. Inflorescence terminal, often recurved, 15-20 cm, densely racemose, pedunculate; rachis 10-15 cm with densely arranged numerous flowers; floral bracts linear-lanceolate, 3.5-4 mm, membranous, greenish-white. Flowers resupinate, spreading, 4-4.5 mm across, white, tinged with pale yellow in the centre; pedicel and ovary 3.5-4 mm, pale yellow or greenish-yellow. Dorsal sepal ovate-oblong, margins often revolute, apex obtuse, 2.5-3 × 0.8-1 mm, translucent white, becoming yellowish towards the base. Lateral sepals obliquely ovate-elliptic, margins often revolute, 2.5-3 × 0.8-1 mm, translucent white, becoming yellowish towards the base. Petals narrowly oblong-falcate, margins revolute, 2-2.5 × 0.3-0.5 mm, translucent white, becoming yellowish towards the base. Lip nearly flabellate-quadrate, 2-2.5 × 1.5-2 mm, base shallowly concave and distinctly recurved from the middle, indistinctly divided into hypochile and epichile; hypochile ecallose, adaxially slightly thickened and fleshy towards the margins on each side; epichile emarginate, apical margins inconspicuously erose, translucent white, furnished with pale yellow at base. Column terete, conspicuously incurved or arcuate above the middle, apex with 2 short, wedge-shaped wings, with the base slightly dilated, 1.0-1.5 mm long, greenish-white, tinged with pale yellow at base. Stigma concave, subelliptic. Rostellum approximately truncate, apex obtuse, yellowish. Anther terminal, 2-celled, persistent, compressed ovoid, ca. 0.5 mm long. Pollinia 4, hard, waxy, yellow, ca. 0.3 mm. Capsule obovoid-ellipsoid, ridged, 4-6 × 2-3 mm; fruiting pedicel 3-5 mm.

Distribution and habitat.

Endemic to Guangxi in China. Lithophytes in rocks crevices where soil or organic matter has accumulated at elevations from ca. 650 m to 900 m in karst limestone forest.

Etymology.

The epithet “napoensis” is derived from the type locality: Napo County, Guangxi, located at China’s southwest border, where the species was discovered.

Phenology.

Flowering and fruiting in January–February.

Conservation status.

Based on careful field investigations in the past years, this species is rare and only known from the type locality. Plants grow in sparsely scattered groups and the known population of two colonies consists of only a few dozen individuals (density less than one plant per 20 m2). In addition, the location is not in a protected area and accessible to casual hikers. According to the guidelines for using the IUCN Red List Categories and Criteria ( IUCN 2017), the species is categorised as Critically Endangered [CR B2ab(iii)] due to its rarity and the threat of disturbance.

Taxonomic notes.

The new species in its general appearance has some superficial similarity with Liparis viridiflora , but the latter differs in longer petioles, narrowly linear petals, ovate-oblong lip with a mucronate tipped apex and a column with rounded wings. It also superficially resembles L. somae , but is characterised by having ovoid-cylindrical or narrowly pyriform pseudobulbs, a flabellate-quadrate lip with a distinctly concave base and an emarginate apex. A detailed morphological comparison between L. napoensis and its closely related taxa L. viridiflora and L. somae is presented in Table 1 .

Figures

Figure 1. Liparis napoensis A Habit in bloom B Flower, lateral view C Flower, front view D Column, ventral view E Column, lateral view F, G Lip H Dorsal sepal I Petal J Lateral sepal. Line drawing by Yun-Xiao Liu. Scale bars: 2.5 cm (A), 2 mm (B, C), 1 mm (D-I).

Figure 2. Liparis napoensis A Habitat B A plant in bloom C Inflorescence D Column, lateral view, showing bract E Flower, frontal view F Flower, lateral view G Column, ventral view, showing bract H, I Lip. Scale bars: 5 cm (A-C), 2 mm (D-G), 1 mm (H, I).