Sunday, January 16, 2022

[Botany • 2022] Gastrochilus pankajkumarii (Orchidaceae: Epidendroideae: Aeridinae) • A New Lithophytic Orchid from southern Vietnam


Gastrochilus pankajkumarii Vuong, Aver., & V.C. Nguyen,

in Nguyen, Averyanov, Maisak, Nguyen, ... & Truong, 2022. 
 Photo by Truong Ba Vuong and Nguyen Van Canh. 

Abstract
Gastrochilus pankajkumarii, found in the Central Highlands of Vietnam, is described as a new species for science. The protologue includes color analytical photos of the new species and data on phenology, ecology, and distribution. Morphological comparisons with similar species are presented.

Keyword: Central Highlands, endemism, flora of eastern Indochina, Gastrochilus sect. Microphyllae

   


Gastrochilus pankajkumarii Vuong, Aver. & V.C. Nguyen, type specimen.
A. Flowering plant. B. Leaf sheath. C. Leaf, adaxial and abaxial surface. D. Apical part of leaf, adaxial and abaxial surface. E. Margin of leaf near the apex. F. Intact inflorescences. G. Flower, frontal, side view, and view from behind. H. Dorsal sepal, adaxial and abaxial surface. I. Lateral sepals, adaxial and abaxial surface. J. Petals, adaxial and abaxial surface. K. Lip, views from different sides; L. Column, ovary and pedicel, frontal view and view from behind. M. Column, frontal view. N. Anther cap, view from above and from below. O. Pollinarium; P. Ripening capsules.
 Photo by Truong Ba Vuong and Nguyen Van Canh. 
Correction and design by L. Averyanov and T. Maisak.

Gastrochilus sect. Microphyllae Bentham & Hooker 

Gastrochilus pankajkumarii Vuong, Aver., & V.C. Nguyen, sp. nov. 

Etymology. The species name honors Dr. Pankaj Kumar for his great contribution to orchid taxonomy and ecology. 

Vernacular names. Túi thơ Pankaj, Túi thơ Chư Mư. 


Notes. The newly described species morphologically resembles Gastrochilus dulongjiangensis Q. Liu & J.-Y. Gao, G. fuscopunctatus, and G. kadooriei, all three of which are known from limestone areas of northeast Indochina and southern China, as well as G. pseudodistichus (King & Pantl.) Schltr., which is more widespread in the Indo-Burma region, including southern Vietnam. Further molecular studies of these species may be useful for understanding their mutual genetic relationships. A critical comparison of the new species with each of these four species is presented in Table 1.
...

Flowering plants of Gastrochilus pankajkumarii Vuong, Aver. & V.C. Nguyen in nature
 (Photo by Nguyen, Van Canh).

Habitat and phenology. Humid primary montane broad-leaved evergreen forest, at an elevation of about 1800–2000 m. a.s.l. Growing lithophytically on mossy granite rocks near mountain summit. Common species in the area. 

Distribution. Southern Vietnam (Dak Lak Province). Endemic of the Central Highlands.  


Van Canh Nguyen, Leonid V. Averyanov, Tatiana V. Maisak, Thi Lien Thuong Nguyen, Van Khuong Nguyen and Ba Vuong Truong. 2022. Gastrochilus pankajkumarii, (Aeridinae, Epidendroideae, Orchidaceae) A New Lithophytic Orchid from southern Vietnam. Taiwania. 67(1); 35-39. DOI: 10.6165/tai.2022.67.35