Saturday, June 22, 2019

[Botany • 2019] Dysosma villosa (Berberidaceae) • A New Species from Guizhou, Southwestern China


Dysosma villosa Z.W.Wang & H.C.Xi

in Wang, Sun, Xi & Chang, 2019. 

Abstract
A new species, Dysosma villosa Z.W.Wang & H.C.Xi, is described and illustrated based on collections from the Yueliang Mountains in Congjiang County of Guizhou, Southwestern China. It is morphologically similar to D. difformis (Hemsl. & E.H.Wilson) T.H.Wang ex T.S.Ying, but can be easily distinguished from D. difformis by its inflorescences bearing a greater number of flowers (5–13 vs. 2–5), white-villous stems, petioles, and abaxial leaf blade, and stigma dark purple-red. In addition, we also compare this new species to the three species of Podophyllum (i.e., P. glaucescens J.M.H.Shaw, P. hemsleyi J.M.H.Shaw & Stearn, and P. trilobulum J.M.H.Shaw) which are insufficiently known and listed as putative members of Dysosma in Flora of China. Dysosma villosa can also be easily distinguished from P. glaucescens (7-flowered; to 40 cm tall) and P. hemsleyi (4-flowered; to 40 cm tall) by its inflorescences bearing a greater number of flowers, relatively smaller stature (9–23 cm tall), stems, petioles and abaxial leaf blade densely white-villose. Although the stems and petioles of P. trilobulum also possess fine short hairs, it can be easily distinguished from D. villosa by its trilobulate leaves, inflorescence with fewer flowers (2–5), and the position of inflorescence (inserted at or above midpoint on petiole of upper leaf).

Keywords: Asia, Berberidaceae, Dysosma, Podophylloideae, Podophyllum, Ranunculales

Figure 1. Holotype of Dysosma villosa Z.W.Wang & H.C.Xi. 

Figure 2. Images of living plants of Dysosma villosa Z.W.Wang & H.C.Xi. A Plant B petiole and stem C abaxial leaf blade D inflorescence E flower F anatomy of flower. 

Figure 3. Dysosma villosa Z.W.Wang & H.C.Xi. A Plant (aerial part) B root C flower D sepal E stamen F pistil.

Dysosma villosa Z.W.Wang & H.C.Xi, sp. nov.

Diagnosis: Dysosma villosa is most similar to D. difformis (Hemsl. & E.H.Wilson) T.H.Wang ex T.S.Ying, but differs from the latter by its inflorescences generally with more flowers (5–13 vs. 2–5), white-villous petioles, stems and abaxial leaf blade and dark purple-red stigma.
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Distribution and habitat: This new species is currently known from Yueliang mountains of Congjiang County, Guizhou Province, Southwestern China. It grows under forests, at an elevation between 800 and 1500 m.

Etymology: The specific epithet is derived from the character (white-villous petioles, stems and abaxial leaf blade) of this species.


Zhiwei Wang, Wenguang Sun, Houcheng Xi and Shuai Chang. 2019. Dysosma villosa (Berberidaceae), A New Species from Guizhou, Southwestern China. PhytoKeys. 124: 77-85. DOI: 10.3897/phytokeys.124.34435