Friday, November 16, 2018

[Botany • 2018] Bulbophyllum chrysolabium (Orchidaceae, Epidendroideae) • A New Species from Yunnan, China


Bulbophyllum chrysolabium L. Li & D.P. Ye

in Li, Ye & Zeng, 2018. 

Abstract
Bulbophyllum chrysolabium, a new species belonging to section Racemosae from Yunnan, China is described and illustrated. The species is related to B. orientale and B. morphologorum, but differs by having the following set of characters: obliquely broadly-based triangular petals with a long filiform apex; lip densely glandular papillose and conspicuously ciliolate along margins; lip auricles well developed, narrowly falcate, tapering to a long sharp point at the apex; stelidia subulate and twisted inwards, slightly exceeding operculum. The conservation status of B. chrysolabium is assessed and taxonomic notes are provided.

Keywords: Menglian County, new taxa, section Racemosae, taxonomy



Figure 1. Bulbophyllum chrysolabium.
 A Habit B Flower, lateral view C Flower, frontal view D Dorsal sepal, petals and lateral sepals, adaxial view E Lip, lateral view F Lip, ventral view G Pollinia H Operculum, ventral view I Column, ventral view J Column and lip, lateral view.
 Scale bars: 2 cm (A), 2 mm (B–D), 1 mm (E–F, I–J), 0.2 mm (G–H). 
Drawn by Yun-Xiao Liu.


Figure 2. Bulbophyllum chrysolabium.
A Habitat B Inflorescences C Close-up of inflorescence D Flower, lateral view showing floral bract E Flower, frontal view F Dorsal sepal, petal and lateral sepal, abaxial view G Lip, ventral view H Column and lip, lateral view.
Scale bars, 1 mm (G), 2 mm (D–F, H).

Bulbophyllum chrysolabium L. Li & D.P. Ye, sp. nov.

 Diagnosis: Bulbophyllum chrysolabium is distinguished from all known congeners by having the following unique combination of features: obliquely broadly-based triangular petals with a long filiform apex; lip densely glandular papillose on both sides and conspicuously ciliolate along margins; lip auricles well developed, narrowly falcate, tapering to a long sharp point at the apex; stelidia subulate and twisted inwards, slightly exceeding operculum.

Taxonomic notes: Bulbophyllum chrysolabium appears to be related to B. orientale Seidenf. (Seidenfaden 1979: 138), especially in narrowly falcate lip auricles and twisted stelidia, but differs in distinctly longer floral bracts (almost twice as long as the pedicel and ovary); petals with long filiform apices, a rather smaller lip (ca. 2.8 mm long), significantly glandular-papillose and ciliolate at margins; stelidia slightly exceeding operculum and distinctly longer than column. With respect to filiform petals, B. chrysolabium is also superficially similar to B. morphologorum Kräenzl. (1908: 89), however, the latter have a fat, conical protuberance or callus on the front of the column near its base and scape much longer than rachis. In addition, it has subulate, not twisted stelidia, considerably longer than operculum; lip auricles not falcate, but rather obtuse at the apex. A detailed morphological comparison between B. chrysolabium and its allied species is presented in Table 1.

Distribution and habitat: So far known only from Menglian County in southwest Yunnan Province, China, growing as an epiphyte amongst mosses on the tree trunk near the edge of river in rather exposed circumstances in subtropical evergreen broad-leaved forest.

Etymology: The specific epithet comes from the Ancient Greek word chryso-golden” and the Latin derived labium labellum”, referring to the golden-yellow lip of the type.



 Lin Li, De-Ping Ye and Song-Jun Zeng. 2018. Bulbophyllum chrysolabium (Orchidaceae, Epidendroideae, Malaxideae), A New Species from Yunnan, China. PhytoKeys. 111: 61-68. DOI: 10.3897/phytokeys.111.28136