Sunday, July 23, 2017

[Botany • 2017] Premna bhamoensis • A New Species (Lamiaceae, Premnoideae) from Kachin State, northeastern Myanmar

Premna bhamoensis  Y. T. Tan & B. Li

In the present study, we describe and illustrate a new speciesPremna bhamoensis Y. T. Tan & B. Li (Lamiaceae), from Myanmar. In the 1980s, this species was transplanted from Bhamo County in northeastern Myanmar to the Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences. The species shows striking morphological similarity to P. menglaensis B. Li, and thus, has been misidentified as the latter for a long period of time. However, morphological comparison revealed that P. bhamoensis is distinct from P. menglaensis in many aspects. Moreover, literature survey and specimen examinations also indicated that P. bhamoensis is undoubtedly different from all seven known congenetic species recorded from Kachin State, Myanmar, and a key for their identification has been provided in this paper.

Keywords: China, morphology, Myanmar, Premna menglaensis, Xishuangbanna Tropical Botanical Garden

Figure 2. Morphological comparison between Premna bhamoensis (AC) and P. menglaensis (ac).
A, a branchlets with inflorescences B, b inflorescences, flowers and calyces (in the blank circle) C, c fruitescences and fruits (arrow show fruiting calyx). 

Figure 1. Premna bhamoensis Y. T. Tan & B. Li, sp. nov.
habit a branchlet with ovate-oblong to elliptic leaves C branchlet and petioles covered by dense brownish pubescences D abaxial surface of leaf blade.

Premna bhamoensis Y.T. Tan & B. Li, sp. nov.

Diagnosis: The species is most similar in morphology to P. menglaensis B. Li, but differs from the latter in having branchlets and petioles densely tomentose (vs. glabrous or glabrescent), leaf blades papery with minute pubescence (vs. leathery and glabrous), flowers green to greenish yellow (vs. red flowers), calyces slightly 2-lipped with five equal lobes (vs. calyces distinctly 2-lipped with entire or minute emarginate lips), and stamens exserted from corolla (vs. included).

Distribution: Per the introduction record, P. bhamoensis is originally collected from northeastern Myanmar, but currently known only from the cultivated type in the Xishuangbanna Tropical Botanical Garden (Figure 4). Based on our experience in examination of Asian Premna specimens, we suspect that the species is probably endemic to Kachin State of Myanmar and distributed in a very small area.

Etymology: The specific epithet of this new species, “bhamoensis”, is derived from the name of the locality, Bhamo County, from where the species was originally collected.

 Yunhong Tan, Derong Li, Yongjun Chen and Bo Li. 2017. Premna bhamoensis (Lamiaceae, Premnoideae), A New Species from Kachin State, northeastern Myanmar.   PhytoKeys. 83: 93-101.  DOI:  10.3897/phytokeys.83.12869