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| Cynanchum quangbinhense Nuraliev & V.T. Pham, in V. T. Pham, T. T. Pham, Trinh, Nguyen, Dao et Nuraliev, 2021. Sát khuyển Quảng Bình || facebook.com/TaiwaniaOffice Photos by V.T. Pham. |
Abstract
This research provides a description and illustrations for a new species from the Phong Nha-Ke Bang National Park, Cynanchum quangbinhense. The distribution, habitat, phenology and conservation assessment for the species are also presented. The new species differs from closely related species, C. ovalifolium in many characters such as leaf shape, inflorescence type, fewer and smaller flowers, colour of petals, margins of the corona, and anthers appendages shape, and differs from C. kwangsiense in having small leaves, umbellate inflorescences, triangular sepals, retuse apex of petals, and plicate margin of corona. Our discovery raises the known species of this genus in Vietnam to seven. In addition, a key to species of Cynanchum in Vietnam, and notes on morphological variation of C. officinale are presented in this paper.
Keyword: Cynanchum kwangsiense, C. ovalifolium, conservation, Indochina, IUCN, National Park, taxonomic key
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| Cynanchum quangbinhense and its natural habitat. A-D. Living plant with inflorescences. E. Habit. F. Leaf, abaxial (left) and adaxial (right) views. G. Natural forest on limestone mountain habitat. Scale bars: E = 2 cm; F = 1 cm. Photos and design by V.T. Pham. |
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| Cynanchum quangbinhense. A-B. Inflorescences, straight and behind views. C-E. Flower, straight, behind, and lateral views. F. Corolla, straight view (corona removed). G. Corona (left), and stigma head (right). H. Pollinaria. Scale bars: A-G = 2mm; H = 0.2 mm. Photos and design by V.T. Pham. |
Cynanchum quangbinhense Nuraliev & V.T. Pham, sp.
nov.
Diagnosis: Cynanchum quangbinhense is
morphologically most similar to C. ovalifolium, but
differs in having lanceolate to broadly lanceolate leaves
with cuneate base and narrowly acute apex, short and
umbellate inflorescences, narrowly ovate petals with apex
retuse, plicate margins of corona, and broadly lanceolate
anther appendages with retuse apex. Cynanchum
quangbinhense differs from C. kwangsiense in having
small leaves, umbellate inflorescences, yellow-green
corolla, and glabrous sepals.
Etymology: The species epithet “quangbinhense” refers to Quang Binh province, the province of the type locality of the new species. The Vietnamese name is proposed here as “Sát khuyển Quảng Bình”.
Van The Pham, Thanh Trang Pham, Ngoc Bon Trinh, Sinh Khang Nguyen, Minh Truong Dao and Maxim S. Nuraliev. 2021. Cynanchum quangbinhense (Apocynaceae: Asclepiadoideae), A New Species from Vietnam, and additional information on C. officinale. Taiwania. 66(4); 459-465. DOI: 10.6165/tai.2021.66.459 taiwania.ntu.edu.tw/abstract/1783
