Monday, March 6, 2023

[Botany • 2022] Lysionotus hagiangensis (Gesneriaceae) • A New Species from northern Vietnam

 Lysionotus hagiangensis C.H. Nguyen & Aver., 

in Bui, Nguyen, Averyanov, Maisak & Nguyen, 2022. 

Lysionotus hagiangensis, a new species from northern Vietnam, is described and illustrated. It morphologically resembles L. chatungii and L. petelotii, but differs markedly by the character of leaf, inflorescence, corolla color, the shape of stamens, and the number of well developed staminodes. We provide detailed information, including morphological descriptions, illustrations, pictures, and information about the habitat of the new species. Lysionotus hagiangensis is confined to a small area of Cao Ma Po Commune, and further explorations are necessary for identification of its real conservation status, which is provisionally assessed now as “Data Deficient” in accordance with IUCN criteria.

Keyword: Ha Giang Province, limestone endemism, Lysionotus chatungi, L. hagiangensis, L. petelotii


 Lysionotus hagiangensis C.H. Nguyen & Aver.
 A. Plant. B. Leaf. C. Prophylls and internodes. D. Bracts. E. Inflorescence. F. Calyx lobes. G. Flower, frontal view. H. Section of corolla showing inner surface with stamens and staminodes. I. Glandular hairs on the adaxial surface of the corolla. J. Stamens and staminodes. K. Flowers, side and half side views. L. Pistil, base of pistil and its apex with stigma.
Photos of L. Averyanov and Cuong Huu Nguyen, 
correction and design by Cuong Huu Nguyen.

Lysionotus hagiangensis C.H. Nguyen & Aver., sp. nov.

Diagnosis. From closest Lysionotus chatungii Taram, A.P. Das & Tag, the new species differs in pubescent leaf petiole up to 3.5 cm long, solitary inflorescence at node, deltoid inflorescence bracts, subequal, green calyx lobes, spirally twisted filaments, and flower with three well developed staminodes.

Etymology. The species is named after the area of its origin.
Local name: Nở Lưng Hà Giang (Vietnamese) 

Habitat. Primary broad-leaved or mixed very humid montane forests on steep rocky slopes composed with eroded karstic limestone at elevations 1700–2000 m a.s.l. where rainy season lasting from May till September with mean temperatures 24–29°C and annual precipitation about 2500 mm (CLIMATE-DATA.ORG).

 Distribution. Northern Vietnam (Ha Giang Province, Quan Ba District, Cao Ma Po Commune, Chin Chu Lin Village, around point 23°05ʹ13.5ʺN 104°48ʹ30.2ʺE). Endemic.

The Doi Bui, Huu Cuong Nguyen, Leonid V. Averyanov, Tatiana V. Maisak and Sinh Khang Nguyen. 2022. A New Species of Lysionotus (Gesneriaceae) from northern Vietnam. Taiwania. 67(3); 322-325. DOI: 10.6165/tai.2022.67.322