Friday, June 17, 2022

[Botany • 2022] Primulina nana (Gesneriaceae) • A New Species from eastern Guangxi, China


 Primulina nana C.Xiong, W.C.Chou & F.Wen,

in Xiong, Chou, Huang & Wen, 2022.
Photographs by Chi Xiong.

Abstract
Primulina nana C.Xiong, W.C.Chou & F.Wen, a new species of Gesneriaceae from limestone areas of Guangxi, China, is described and illustrated here. It morphologically resembles P. yangshuoensis Y.G.Wei & F.Wen in papillose leaf surface, but can be easily distinguished from the latter by noting a combination of characteristics, especially in its leaf blades, leaf blade indumentum characteristic, calyx lobes, corolla and the disc. We found only one population at the type locality, about 200 mature individuals. According to the IUCN Red List Categories and Criteria (Version 3.1), the new species is provisionally assessed as Critically Endangered (CR).

Keywords: Flora of Guangxi, Gesneriaceae, new taxon, Primulina yangshuoensis, taxonomy

 Primulina nana sp. nov.  
A habit B adaxial side of leaves C abaxial side of leaves D alabastrum E bracts and calyx F abaxial side of calyx lobes G adaxial side of calyx lobes H lateral view of a flower I ventral view of a flower J top view of a flower K front view of a flower s howing the internal structure L opened corolla M stamens and staminodes N pistil with calyx O disc and ovary P capsule.
Photographs by Chi Xiong.

 Primulina nana C.Xiong, W.C.Chou & F.Wen, sp. nov.
 
Diagnosis: The new species resembles Primulina yangshuoensis (Fig. 2A2–F2) in papillose leaf surface, namely numerous single pubescent hair on papilla on surface, but can be easily distinguished from the latter by its leaf blade elliptic to ovate, 1.6–1.8 × 1.1–1.3 cm (vs. broadly ovate-round, subround or round, 3.5–6.5 × 2–4.5 cm); leaf nearly erect semi-transparent papillose-puberulent and white pubescent (vs. densely erect semi-transparent and white multicellular papillose-hispid); peduncle 3–5 cm long (vs. 8–9 cm); calyx lobes with one serration (vs. entire); corolla ca. 1.5 cm long, tube tubular (vs. 2–3 cm, broadly infundibuliform); disc ca. 0.6 mm high (vs. ca. 1 mm). Detailed morphological comparisons with P. yangshuoensis are provided in Table 1.



Morphological comparison of Primulina nana sp. nov. (1) with P. yangshuoensis (2)
A habitat B habit C leaf blades D front view of flowers E lateral view of flowers F top view of flowers.
A1 and D1 photographed by Wei-Chuen Chou; 
B1–C1, E1–F1, C2 photographs by Chi Xiong; 
A2–B2 and D2–F2 photographed by Fang Wen.

Etymology: The specific epithet ‘nana’ is derived from the dwarf plants of the new species compared with that of most other species of Primulina.

Vernacular name: 玲珑报春苣苔 (Chinese name); 
Líng Lóng Bào Chūn Jù Tái (Chinese pronunciation).

Distribution and habitat: Primulina nana is only known from the type locality, Xinxu Town, Mengshan County, Wuzhou City, Guangxi, China. It grows on moist, shady limestone rock surfaces, at an elevation of ca. 530 m.


Chi Xiong, Wei-Chuen Chou, Yi Huang and Fang Wen. 2022. Primulina nana (Gesneriaceae), A New Species from eastern Guangxi, China. PhytoKeys. 197: 33-39. DOI: 10.3897/phytokeys.197.83089