Wednesday, March 7, 2018

[Botany • 2018] Ophiorrhiza guizhouensis • A New Species (Rubiaceae) from Guizhou Province, southwestern China


Ophiorrhiza guizhouensis  C.D.Yang & G.Q.Gou

in Yang, He & Gou, 2018.  

Abstract
In this study, Ophiorrhiza guizhouensis, a new species of Rubiaceae from south-western China, is described and illustrated. The new species is morphologically similar to O. japonica, but differs from the latter by having terete stems which are densely hirtellous, usually persistent ciliate stipules with well-developed colleters inside the base of the stipule, shorter corolla tubes and shorter stamens and styles.

Keywords: Ophiorrhiza, Guizhou, China, new taxa, distyly


Ophiorrhiza guizhouensis  C.D.Yang & G.Q.Gou   
 D inflorescence, showing longistylous flowers E dissected longistylous flower F pistil of longistylous flower
G inflorescence, showing brevistylous flowers H dissected brevistylous flower I pistil of brevistylous flower.

Figure 2. Ophiorrhiza guizhouensis A habit B leaves C node, showing persistent stipule (blue arrow) and colleters (red arrow), also showing stem pubescence D inflorescence, showing longistylous flowers E dissected longistylous flower F pistil of longistylous flower G inflorescence, showing brevistylous flowers H dissected brevistylous flower I pistil of brevistylous flower.

Ophiorrhiza guizhouensis C.D.Yang & G.Q.Gou, sp. nov.

Diagnosis: Similar to O. japonica Blume, but distinguished from the latter by the terete, densely hirtellous stems (vs. stems subterete to slightly compressed, glabrous or with 2 hirtellous or pilosulous lines), the usually persistent and ciliate stipules (vs. caducous glabrescent stipules), the well-developed colleters inside the base of stipule (vs. without colleters), the shorter corolla tubes (8–9 mm vs. 9–14 mm) and the shorter stamens and styles (longistylous flower: 2.5–2.7 mm and 7–8 mm vs. 4.5–5.5 mm and 9–11 mm; brevistylous flower: 3.6–4.2 mm and ca. 2.5 mm vs. 4.5–5 mm and ca. 3 mm).

Distribution and habitat: Ophiorrhiza guizhouensis is currently only known from Jiangkou County, Guizhou, south-western China, where at least 300 individuals are found. The species grows in evergreen broad-leaved forest or bamboo forest at elevations between 850–1,000 m, along with Chimonobambusa angustifolia C.D. Chu & C.S. Chao, Lindera communis Hemsl., Lpulcherrima var. hemsleyana (Diels) H.B. Cui, Clematis henryi Oliv. and Ophiopogon bodinieri H. Lév.

Etymology: The specific epithet refers to Guizhou, a province of south-western China in which the new species was collected.


 Chuan-Dong Yang, Xuan-Ze He and Guang-Qian Gou. 2018. Ophiorrhiza guizhouensis (Rubiaceae), A New Species from Guizhou Province, southwestern China. PhytoKeys. 95: 121-126. DOI: 10.3897/phytokeys.95.22506