Lasianthus sondangii (Rubiaceae, Lasianthus section Nudiflorae), a new species with a unique spiciform inflorescence from Central Vietnam

Lasianthus sondangii (Rubiaceae, Lasianthus section Nudiflorae), a new species with a unique spiciform inflorescence from Central Vietnam

Lasianthus sondangii, a new species from Lasianthus section Nudiflorae, is described from Khanh Hoa Province, Central Vietnam. It can be distinguished from other Lasianthus species in Vietnam and surrounding countries by having narrowly triangular stipules, spiciform inflorescences with two or three reduced cyme secondary axes, purple flowers, and clavate calyx lobes with revolute margins. A detailed description of the new species, color plates, distribution, habitat and preliminary conservation assessment are provided.