Clematis wuxiensis Q.Q. Jiang & H.P. Deng, 2017

Jiang, Qing-Qing, Deng, Hong-Ping, Qian, Wang, Yang, Zhi-Ming & Zhang, Hua-Yu, 2017, Clematis wuxiensis (Ranunculaceae), a new species from Chongqing, China, Phytotaxa 296 (2), pp. 197-200 : 197-199

Clematis wuxiensis Q.Q. Jiang & H.P. Deng , sp. nov. ( Figs. 1 , 2)

Type: — CHINA. Chongqing: Wuxi, Yintiaoling National Nature Reserve, forest margins, 31°32 ′ 11 ″ N, 109°41 ′ 51 ″ E, ca. 2200 m a.s.l., 30 May 2016, Q. Q Jiang & H. P. Deng 075 (holotype SWU, isotype IBSC).

Woody vine. Stem 1–3 m long, cylindrical, often shallowly 6–12-grooved, branchlets slender, 1–4 mm across, puberulous, glabrescent. Leaves usually 2-pinnate with 9 leaflets, rarely 1-pinnate with 5 leaflets; leaflet blades rhombic-lanceolate, rhombic-ovate or narrowly ovate, 0.8–3.2 (–4) × 0.5–1.7 cm, papery, undivided or 3-lobed, both surfaces sparsely puberulous, base cuneate to broadly cuneate, margin sparsely dentate, apex acuminate, terminal leaflets petiolulate, lateral leaflets sessile. Flowers (1 or) 2–6 together with several leaves arising from axillary buds of old branches. Pedicel 2–8 cm long. Sepals 4, spreading, white or sometimes tinged pink, obovate to oblong-obovate, 1.5–2.5 × 0.8–1.5 cm, adaxially glabrous, abaxially puberulous. Stamens 5–12 mm long, glabrous; anthers narrowly oblong, 1.5–3.5 mm long, apex obtuse. Ovaries glabrous or rarely puberulous. Style 5–9 mm long, densely villous. Achenes ovate, 3–3.9 × 2–3 mm, glabrous; persistent style 2.3–3.3 cm long, plumose. Fl. Apr–Aug, fr. Jul–Oct.

Etymology:— The specific epithet refers to Wuxi, Chongqing, China, the type locality of the new species.

Distribution and Habitat:— Clematis wuxiensis is currently known only from its type locality, i.e. the Yintiaoling National Nature Reserve in Wuxi, Chongqing, China ( Fig. 3 ). It grows at forest margins at an elevation of ca. 2200 m a.s.l.

Phenology:— Flowering April to August; fruiting July to October.

Additionally specimens examined (paratypes):— CHINA. Chongqing: Wuxi, Q.Q Jiang & H.P. Deng 093 (SWU), 127 (SWU).

Notes:— Clematis wuxiensis is closely similar to C. montana and C. gracilifolia in the flowers together with several leaves arising from axillary buds of old branches and four spreading sepals, but it is distinguishable at once from the latter two species in the usually 2-pinnate leaves with nine leaflets (vs. always ternate or ternate to 1-pinnate with three to five leaflets). Moreover, C. gracilifolia and C. wuxiensis are geographically independent from each other, with the former occurring in southeastern Gansu, western and northwestern Sichuan and northwestern Yunnan, while the latter currently known only from its type locality, i.e. Wuxi in northeastern Chongqing.

Clematis wuxiensis can be readily referred to C. sect. Cheiropsis Candolle (1817: 162). Wang & Li (2005) subdivided this section into eight subsections. According to this classification, Clematis wuxiensis should be further placed in ser. Montanae Rehder & Wilson (1913: 331) under subsect. Montanae Schneider (1906: 290). It is worth mentioning that recent molecular phylogenetic analyses of the genus Clematis based on nuclear ITS and three plastid regions have not indicated the monophyly of C. sect. Cheiropsis as traditionally defined, although several taxa of the section from southwestern China, including C. montana , have nevertheless been revealed to form a well-supported monophyletic clade ( Xie et al. 2011).

FIGUERE 2. Clematis wuxiensis in the wild. A. Habitat. B. Flowering plant. C. Flower (not fully open). D. Flower (top view). E. Flower (lateral view). F. Part of flowering plant, showing flowers and leaves arising from axillary buds of an old branch. G. Leaf (adaxial side). H. Leaf (abaxial side). I. Part of fruiting plant. J, K. Achenes. Scale bars 1 cm.

Figures

FIGURE 1. Clematis wuxiensis. A. Part of flowering plant. B. Leaf (adaxial side). C. Leaf (abaxial side). D. Sepal (adaxial side). E. Sepal (abaxial side). F. Longitudinal section of flower. G. Inner stamens (the left two ones) and outer stamens (the right two ones). H. Style. I. Achene. J. Achenes.

FIGURE 3. Distribution of Clematis wuxiensis (●).