[Botany • 2024] Isodon xiaoluzhiensis (Lamiaceae: Nepetoideae) • A New Species from Yunnan, southwest China

Isodon xiaoluzhiensis  Huan C. Wang & Shi Gang Li,

in Li, Huang, Liu, Xiang et Wang, 2024.

小绿汁香茶菜  ||  DOI: 10.3897/phytokeys.237.117071

Abstract

Isodon xiaoluzhiensis, a new species of the tribe Ocimeae in family Lamiaceae, is described and illustrated. The new species is known only from the type locality, Xiaoluzhi village in Luzhijang dry-hot valley of Yimen County, central Yunnan, southwest China. It is characterized by having a procumbent habit, gracile stems and branches, relatively small leaves and flowers, and the phenology of flowering in winter. The morphological comparisons with its putative closest relatives (I. adenanthus and I. hsiwenii) are also presented.

Key words: Asia, Dry-hot valley, endemism, limestone grassland, phenology, procumbent shrub

Isodon xiaoluzhiensis sp. nov.
A, B habit C perennial stem D branchlet E adaxial surface of leaf F abaxial surface of leaf G–I inflorescence J corolla (front view) K flower (lateral view) L corolla (rear view) M calyx.

 Isodon xiaoluzhiensis Huan C. Wang & Shi Gang Li, sp. nov.

 

Diagnosis: Isodon xiaoluzhiensis is most similar to I. adenanthus (Diels) Kudô in having similar flower shape, but it clearly differs from the latter in its procumbent (vs. erect or ascending in I. adenanthus) habit, stems and branches woody (vs. non-woody) with densely white glandular puberulent (vs. densely retrorse gray pubescent), leaves usually narrowly ovate to rhomboid, rarely lanceolate (vs. rhombic-ovate to ovate-lanceolate), small, 0.8–1.4 cm long (vs. 1.5–6.5 cm long), 0.2–0.5 cm wide (vs. 1.0–2.5 cm wide), teeth of calyx subobtose to subacute (vs. apiculate) at apex, posterior lip of corolla non-spotted (vs. purple spotted). Additionally, I. xiaoluzhiensis flowers from November to January, nevertheless I. adenanthus usually flowers from March to August.

Etymology: The specific epithet “xiaoluzhiensis” is derived from the type locality of the new species, the Xiaoluzhi village, and the Latin suffix -ensis, indicating the place of origin or growth.

Vernacular name: Chinese mandarin: xiao lu zhi xiang cha cai (小绿汁香茶菜).

  

 Shi-Gang Li, Qiang-Chun Huang, Shao-Yun Liu, Chun-Lei Xiang and Huan-Chong Wang. 2024. Isodon xiaoluzhiensis (Lamiaceae, Nepetoideae), A New Species from Yunnan, southwest China. PhytoKeys. 237: 191-200. DOI: 10.3897/phytokeys.237.117071