Friday, February 15, 2019

[Botany • 2019] Clematis mae (Ranunculaceae) • A New Species of Clematis sect. Meclatis from Xinjiang, China

Clematis mae Z.Z.Yang & L.Xie

in He, Lyu, Yao, Xie & Yang, 2019. 

Clematis mae Z.Z.Yang & L.Xie, a new species of Ranunculaceae from Xinjiang, China, is described and illustrated. The new species is morphologically similar to C. orientalis and C. glauca but can be distinguished for being a less hairy plant (hairy in C. orientalis), often 2-ternate leaves (1–2-pinnate for C. orientalis and C. glauca), lanceolate to linear-lanceolate leaflets (elliptic or ovate in C. glauca), larger flowers (smaller flower in C. orientalis) and narrowly lanceolate sepals with acute to slightly attenuate apex (narrowly oblong sepals in C. orientalis and ovate to broadly lanceolate sepals in C. glauca). The new species is endemic to the southern slope of North Tianshan Mountain in Central Xinjiang. The conservation status of the species is also discussed.

Keywords: Anemoneae, Asia, Eudicots, Ranunculales, vine

Figure 2. Illustration of Clematis mae Z.Z.Yang & L.Xie.
Drawn by S.F. Li

Figure 1. Holotype specimen (M. Ma & Z.Z. Yang 99348, deposited in BJFC) of the new species, Clematis mae Z.Z.Yang & L.Xie, collected from Yuer gou, Toksun, Xinjiang, China. 

Clematis mae Z.Z. Yang & L. Xie, sp. nov.

Diagnosis: The new species is most similar to C. orientalis L. and C. glauca Willd. and it can be distinguished from the latter two species by the following combinations of characteristics. Plants of the new species are less hairy than C. orientalis and, in this respect, are similar to C. glauca. The leaves of the new species are often 2-ternate, with lanceolate to linear lanceolate leaflets. Its leaflets are larger than those of C. orientalis, but narrower than those of C. glauca. The flowers are also significantly larger than those of C. orientalis and slightly larger than those of C. glauca. The sepals of the new species are also less hairy than those of C. orientalis and similar to those of C. glauca. The shape of the sepal is lanceolate and the apex is acute to slightly attenuate. In C. orientalis, the sepals are often linear, oblong and reflexed. The sepals of C. glauca are often wider than those of the new species (Table 1, Fig. 3).

Figure 3. Field photographs of three closely related species of Clematis sect. Meclatis
A–C Clematis mae Z.Z.Yang & L.Xie. (photo taken by M. Ma & Z.Z. Yang) A Biternate leaf and flower buds B Ascending flower and its outside sepals C Flower inside
 D–F Clematis orientalis L. (photo taken at Shihezi, Xinjiang, China, by Z.Z. Yang) D Habitat and plants of C. orientalis E Flower showing spreading and reflexed sepals F Flower showing discernible hair on the inside sepals
G–I Clematis glauca Willd. (photo taken at Liancheng, Gansu, China, by J. He and L. Xie) G Habitat and plant in flower H Cyme and leaves I Flower and young fruit.

Distribution: Only known from its type locality, Yuer gou, Toksun, Xinjiang, China.

Etymology: The species epithet is chosen in honour of the collector, Ms. Ma Ming, who first noticed this new species and guided the last author to collect specimens.

Vernacular name: Ming Tie Xian Lian (明铁线莲; new Chinese name)

 Jian He, Ru-Dan Lyu, Min Yao, Lei Xie and Zong-Zong Yang. 2019. Clematis mae (Ranunculaceae), A New Species of Clematis sect. Meclatis from Xinjiang, China. PhytoKeys. 117: 133-142. DOI: 10.3897/phytokeys.117.31854