Premna is a genus of flowering plants in the mint family, Lamiaceae. It is widespread through tropical and subtropical regions.

During fieldwork in 2016 and 2017, researcher from Xishuangbanna Tropical Botanical Garden (XTBG) encountered and collected an unusual Premna L. plant. After sufficient literature consultation, specimens examinations,  and detailed morphological comparisons, the researchers confirmed that this species is new to science. They named it as Premna grandipaniculata and got it published in PhytoKeys.

Premna grandipaniculata is a huge woody climber bearing large, complicated paniculiform inflorescences and large, suborbicular, glabrous leaves. The terminal branches of the inflorescence are spike-like thyrses formed by sessile cymes laxly arranged on the axis.

Premna grandipaniculata shares the same primary inflorescence structure with P. bracteata and P. interrupta, but is distinct from the latter two in its spike-like thyrses forming a panicle with tertiary branches and in having nearly glabrous branchlets, petioles, leaves and inflorescences.

This species is only known from a single locality in Myanmar and as the habitat, in which it is found, is threatened by deforestation. Based on the guidelines of the International Union for Conservation of Nature, it is categorized as critically endangered under criteria B and D following IUCN Red List Categories.

Contact

TAN Yunhong Principal Investigator

Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China

E-mail: tyh@xtbg.org.cn

Morphological comparisons amongst Premna grandipaniculata (A–C), P. bracteata (D–F) and P. interrupta (G–I). A, D, G habit B, E, H branchlets with leaves C, F, I inflorescences.

(Images by TAN Yunhong)