[Botany • 2019] Gentiana bolavenensis (Gentianaceae) • A New Species from Dong Hua Sao National Protected Area in southern Laos

Gentiana bolavenensis Nagah., Tagane & Soulad.

in Nagahama, Tagane, Souladeth, et al,, 2019. 

Wheed Bolaven | ຫວີດບໍລະເວນ || DOI: 10.20531/tfb.2019.47.2.02

ABSTRACT

A new species of Gentiana, Gentiana bolavenensis (Gentianaceae) is described from Dong Hua Sao National Protected Area in southern Laos, with photographs, a vernacular name and a preliminary conservation status.

KEYWORDS:  Bolaven Plateau, flora, Gentianales, Indochina, taxonomy

 Figure 2. Gentiana bolavenensis Nagah., Tagane & Soulad.: 
A & B. habit; C. abaxial leaf surface; D. pale purple flower, top view; E. light pale blue flower, top view; F. flower opened; G. side view of flower bud; H. calyx opened out; J. outside of corolla opened; K. corolla opened out showing stamens; L. pistil.

Scale bars: H–L = 5 mm. H–L from Tagane et al. L2116 (FOF). 

Gentiana bolavenensis Nagah., Tagane & Soulad., sp. nov.

Gentiana bolavenensis is similar to G. ting-nung-hoae Halda and G. laotica, but differs from the former in having a larger size (9.5–18.3 cm tall in G. bolavenensis vs. 1–7(–10) cm tall in G. ting-nung-hoae), longer calyx tube and lobes (calyx tube 4 mm long, lobes 6–7 mm long, vs calyx tube 2.5 mm, lobes 2–3 mm long, respectively), longer stamens (ca 6 mm long vs 4–4.5 mm long) and shorter stigma (1 mm long vs 2–2.5 mm long), and from the latter in having light pale blue or pale purple corolla (vs whitish in G. laotica) and lanceolate, narrowly elliptic,oblanceolate leaves (vs obovate to obovate-oblong in G. laotica)

 Etymology.— The specific epithet refers to the Bolaven Plateau where we collected the plant.

Distribution.— Laos (so far known only from Dong Hua Sao National Protected Area; Fig. 1).

Ecology.— Three small populations each consisting of ca 20–30 individuals were found in the open grasslands on the top of Bolaven Plateau, at altitudes of 1,239 m, 1,260 m and 1,268 m (Fig. 2). From the latter two, we collected the above specimens.

Vernacular name.— Wheed Bolaven (ຫວີດບໍລະເວນ) (suggested here).

Ai Nagahama, Shuichiro Tagane, Phetlasy Souladeth, Anousone Sengthong and Tetsukazu Yahara. 2019. Gentiana bolavenensis (Gentianaceae), A New Species from Dong Hua Sao National Protected Area in southern Laos. Thai Forest Bulletin (Botany). 47(2), 133-136. DOI: 10.20531/tfb.2019.47.2.02