Parnassia xinganensis C.Z. Gao & G.Z. Li, 1983: 19.

Dai, Xiao-Song, Min, Dao-Zhang, Yang, Bo, Wu, Ding & Li, Bo, 2021, Taxonomic note of Parnassia (Celastraceae) in China II: population surveys reveal that P. guilinensis is conspecific to P. xinganensis, PhytoKeys 172, pp. 67-73 : 67

Parnassia xinganensis C.Z. Gao & G.Z. Li, 1983: 19. Figs 1 , 2

Type.

China. Guangxi: Guilin City, Xing’an County, Mao’er Mountain, streamsides in valleys, alt. 1200 m, 11 December 1978, G.Z.Li 62923 (holotype: IBK00185227!; isotype: IBK00200466!).

= Parnassia guilinensis G.Z. Li & S.C. Tang, syn. nov. Type: China. Guangxi: Guilin City, Xing’an County, Mao’er Mountain, streamsides, alt. 580 m, 23 August 1998, G.Z.Li & S.C.Tang M93 (holotype: IBK00200636!).

Description.

Perennial herbs, glabrous. Rhizome sympodial, robust. Stems 1-8, 5-20 cm tall, usually with 1 cauline leaf near middle. Basal leaves (4-) 8-13 (-22); petiole (1-) 4.5-6.5 (-9.5) cm long; leaf blade elliptic, obovate-elliptic, oblong-ovate to ovate, abaxially gray-white, adaxially green, (1-) 3-5.5 (-7.5) × (0.8-) 1.5-2.5(-3) cm, inconspicuously 5-7-veined on both surfaces, midvein prominent, base rounded, subtruncate to cuneate, apex obtuse to acute. Cauline leaf sessile, amplexicaul, ovate or ovate-triangular, 0.9-2.4 × 0.5-1.6 cm. Flowers 1.5-2.3 cm in diam.; hypanthium shortly campanulate or inconspicuous. Sepals green, elliptic to ovate, 3.7-5.2 × 2.3-3.7 mm, 5-veined, margin entire, apex obtuse. Petals spreading, white, elliptic to broadly obovate, 8.5-12 × 6.8-8.3 mm, 5-veined basally, base attenuate into a claw, 2-3 mm long, margin entire or slightly undulate, apex rounded, obtuse or emarginate. Anthers ellipsoid; filaments 2-7 mm long; staminodes flat, 3-3.5 mm long, 3-5-branched to middle, branchedes globose glandular at apex. Ovary superior, greenish, ovoid, slightly sunken into hypanthium; styles short, ca. 1-1.5 mm long; stigma 3-lobed, lobes oblong, spreading. Capsule ovoid, trigonous, 5-10 mm long, 3-valved. Seeds minute, oblong, ca. 1 mm long.

Phenology.

Flowering - late June to November; fruiting - August to December.

Distribution and habitat.

The species is endemic to northeastern Guangxi Province (recorded only in Xing’an County and Ziyuan County), China, and grows in clefts of the moist rocks along streams or under waterfalls, at an elevation of 400-1350 m.

Additional specimens examined.

China. Guangxi: Guilin City, Xing’an County, Mao’er Mountain, streamsides, moist rocks in valleys, alt. 580 m, 23 August 1998, G.Z.Li & S.C.Tang M211 (IBK00200637!); under forests, alt. 611 m, 29 September 2014, Xing’an Expedition 450325140929020LY (GXMG0110865!); Ziyuan County, Mao’er Mountain, on rocks under forests, near streams, 6 December 1980, G.Z.Li 10120 (IBK!).

Conservation status.

At present, P. xinganensis has been reported only from two counties in northeastern Guangxi Province of China. Based on our field investigations, there are numerous mature individuals and young seedlings which could be easily discovered along streams and under waterfalls, indicating the population survives and regenerates well. Additionally, the Mao’er Mountain has been projected to a national nature reserve of China in 2003, and ranks among one of the earliest national nature reserves founded in Guangxi Province. It is apparent that the species will not be severely affected by human activities, thus we propose to list P. xinganensis as Least Concern (LC) according to the IUCN Red List categories and criteria ( IUCN 2017).

Figures

Figure 1. Type specimens of Parnassia xinganensis (A) and P. guilinensis (B).

Figure 2. Morphological comparisons between Parnassia xinganensis (A 1 - A 5) and P. guilinensis (B 1 - B 5) collected from their type localities of Mao'er Mountain at altitudes of 1200 m and 580 m, respectively A 1, B 1 habitat A 2, B 2 flower A 3, B 3 calyces, staminodes and ovary A 4, B 4 petals A 5, B 5 variation of staminodes.