Wednesday, November 22, 2023

[Botany • 2023] Bulbophyllum dresslerianum (Orchidaceae: Epidendroideae) • A New Species of Bulbophyllum sect. Tripudianthes from Southern Yunnan, China


 Bulbophyllum dresslerianum Z. D. Han & H. Wang, 

in Han, Ren, Jiang et Wang, 2023. 
 
Abstract 
Bulbophyllum dresslerianum Z. D. Han & H. Wang (Orchidaceae), a new species from southern Yunnan, China, is described and illustrated. The new species belongs to section Tripudianthes Seidenf., sharing some vegetative and floral traits with B. dickasonii, B. kanburiense, B. rugosisepalum and B. tripudians, but differs on the basis of a suite of floral characters. Globular papillae decorate the lip epichile with the abaxial side and margins bearing sparse short glandular hairs. In addition, its lateral sepals are brownish-yellow and glabrous. A key to B. dresslerianum and its related species is provided. Currently, this species is only found in one population, its conservation status requires further assessment.

Key words: New species; Bulbophyllum; Labellum/lip; Section Tripudianthes; Sourthern Yunnan

 Bulbophyllum dresslerianum.
A: Bract; B: Dorsal sepal; C: Petals; D: Plant; E: Sepals, petals, and lip; F: Flower (front view); G: Column with ovary; H: Lip (lateral view); I: Lip (dorsal view).
All photos from a flower of the holotype.

 Comparison of three related species with Bulbophyllum dresslerianum.
A: Plant of B. dresslerianum; B: B. dresslerianum; C: B. tripudians; D: B. dickasonii; E: B. rugosisepalum;
1: Flower (front view); 2: Dorsal sepal; 3: Petal; 4: Lip
(Drawn by Lan Yan and Lin Wang based on type photos of B. dresslerianum and B. dickasonii, and drawing of B. tripudians).

Bulbophyllum dresslerianum Z. D. Han & H. Wang sp. nov.  

Diagnosis: Bulbophyllum dresslerianum is similar to B. dickasonii, B. kanburiense, B. rugosisepalum, and B. tripudiansin terms of morphological structure of flowers. This new species can be distinguished from B. rugosisepalum by dorsal sepal ovate to narrowly ovate, lateral sepals absent rugose-papillae, and the margins and adaxial side of epichile with sparely short glandular hairs. It can be distinguished from B. tripudians with the epichile of lip with globular papillae. In addition, the new species can be distinguished from B. dickasonii and B. kanburiense with the margins of dorsal sepals irregularly fimbriated, the petal ovate-lanceolated and the margins of petal fimbriated.

Etymology: The species is named for the late Robert Louis Dressler (1927—2019), an authority on the taxonomy of Neotropical Epidendroideae (including the Malaxideae) and his contributions to the evolutionary ecology of the Orchidaceae.

Chinese vernacular name: 斯勒卷瓣兰(sī lè juǎn bàn lán)


Han Zhoudong, Ren Zongxin, Jiang Hong and Wang Hong. 2023. Bulbophyllum dresslerianum (Malaxideae: Orchidaceae), A New Species from Southern Yunnan, China. Journal of Tropical and Subtropical Botany. 31(2); 272-278.DOI: 10.11926/jtsb.4578