Wednesday, March 15, 2023

[Botany • 2023] Smilax bolavenensis (Smilacaceae) • A New Species from southern Laos

 Smilax bolavenensis  Tagane & Soulad., 

in Tagane, Souladeth & Tamuram 2023.

A new species of Smilax, S. bolavenensis (Smilacaceae), is described from the Bolaven Plateau, southern Laos. It is similar to S. elegantissima in its elongated inflorescence with slightly zigzagged rachis longer than 20 cm, but the new species is distinguished by its terete stem and petiole (vs. 4-angled with each corner narrowly winged in S. elegantissima) and 42–54-flowered umbels (vs. 7–12). A description, photographs and preliminary conservation status are also provided for S. bolavenensis.
Keywords: angiosperms, endemic, Indochina, Liliales, South-East Asia, taxonomy, Monocots

 Smilax bolavenensis.
A. Leafy branch. B. Branch with staminate inflorescence. C. Abaxial leaf surface. D., E. Staminate inflorescence. F. Longitudinal section of a staminate umbel. G. Bracteole. H. Staminate flower bud with bracteoles (left), staminate flower bud (middle), and staminate flower bud outer three tepals and one inner tepal removed showing stamens (right). I. Outer tepals (top) and inner tepals (bottom), adaxial side (left), abaxial side (middle and right).
A–C from Tagane et al. L1964 (KAG); D–G from Souladeth et al. L3342 (KAG).
 Scale bars: F = 5 mm, G–I= 2 mm. 
Photographed by S. Tagane.

Smilax bolavenensis Tagane & Soulad., sp. nov. ( Figs 1  , 2  )

Smilax bolavenensis is similar to S. elegantissima Gagnepain (1934b: 619) from Vietnam in having an elongate inflorescence with slightly zigzag rachis longer than 20 cm, but clearly distinguished from it by its terete stem and petiole (vs. 4-angled with each corner narrowly winged) and 42–54-flowered umbels (vs. 7–12).

Etymology:— Referring to the type locality, Bolaven Plateau. 
Vernacular name:— Kheau kheaung Bolaven (__ບໍລະເວນ; Lao), suggested here. 
Kheau kheaung in Lao refers to a common name for Smilax .

Shuichiro Tagane, Phetlasy Souladeth and Minoru N. Tamura. 2023. Smilax bolavenensis, A New Species of Smilacaceae from southern Laos.  Phytotaxa. 585(1); 55–60. DOI: 10.11646/phytotaxa.585.1.6