Wednesday, October 7, 2026

[Botany • 2026] Beaumontia laotica (Apocynaceae) • A New Species from central Laos

 

Beaumontia laotica X.D. Ma, H.C. Xi, S. Lorphengsy & J.Y. Shen, 

in Ma, Xi, Lorphengsy et Shen, 2026.

Abstract
Beaumontia laotica X.D. Ma, H.C. Xi, S. Lorphengsy & J.Y. Shen (Apocynaceae) is described as a new species from Bolikhamxai Province, Laos. It closely resembles B. grandiflora, B. murtonii and B. jerdoniana, but differs from them by several features of the leaves, sepals and corolla, and by flowering in November. A full taxonomic description, diagnostic illustration and formal IUCN conservation assessment are presented for the new species. An identification key to all species of Beaumontia is provided.

Beaumontia laotica (from the holotype).
 — A: Branch. — B: Longitudinal section of flower. — C: Style-head and anther, side view. — D: Anther, adaxial view. — E: Anther, abaxial view. — F: Ovary, side view.

Beaumontia laotica (A and B photographed at type locality, 11 November 2025; C–P from the holotype).
— A: Natural habitat. — B: Habit. — C: Branch. — D: Young stem. — E: Leaf, adaxial view. — F: Leaf, abaxial view. — G: Adaxial leaf surface. — H: Abaxial leaf surface. — I: Inflorescence. — J: Bracts, adaxial views. — K: Sepals, adaxial views. — L: Flower, front view. — M: Longitudinal section of corolla showing inner surface and stamens. — N: Pedicel and pistil, side view. — O: Disc and ovary, front view. — P: Ovary, side view.

Beaumontia laotica X.D. Ma, H.C. Xi, S. Lorphengsy & J.Y. Shen, sp. nova

Diagnosis. Beaumontia laotica differs from B. grandiflora, B. murtonii and B. jerdoniana by its lanceolate or narrowly obovate (vs. elliptic or obovate) leaf blade; persistent (vs. deciduous) bracts; glabrous (vs. pubescent) sepals; and glabrous (vs. pubescent or puberulent) corolla tube, lower portion ca. 7.4 cm long (vs. 1.5–2.5 cm long), upper portion abruptly expanding to trumpet-shaped, ca. 2 cm long (vs. obconical or campanulate, 6.5–11 cm long). 


Xing-Da Ma, Hou-Cheng Xi, Sengvilay Lorphengsy and Jian-Yong Shen. 2026. Beaumontia laotica (Apocynaceae), A New Species from central Laos. Annales Botanici Fennici. 63(1), 233-237. DOI: doi.org/10.5735/085.063.0130  (11 September 2026)