Research Article |
Corresponding author: Ding Wu ( parnassia@126.com ) Corresponding author: Bo Li ( hanbolijx@163.com ) Academic editor: Mark P. Simmons
© 2021 Xiao-Song Dai, Dao-Zhang Min, Bo Yang, Ding Wu, Bo Li.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Dai X-S, Min D-Z, Yang B, Wu D, Li B (2021) Taxonomic note of Parnassia (Celastraceae) in China II: population surveys reveal that P. guilinensis is conspecific to P. xinganensis. PhytoKeys 172: 67-73. https://doi.org/10.3897/phytokeys.172.62749
|
Based on investigation of populations of Parnassia guilinensis and P. xinganensis, examination of herbarium specimens (including types), as well as consultation of protologues and distributions, P. guilinensis is hereby reduced to a synonym of P. xinganensis. P. xinganensis is endemic to northeastern Guangxi Province of China and characterized by having elliptic to ovate leaves and staminodes 3–5-branched with globose glands. Field photographs and an updated morphological description of P. xinganensis are provided.
Endemic species, morphology, staminode, synonymy, taxonomy
Parnassia L. consists of small, glabrous and rosulate perennial herbs, with several morphologically distinguishable traits, including a solitary, terminal, bisexual and pentamerous flower borne on an unbranched scape; five showy staminodes; and one-by-one stamen movement (
In the taxonomy of Parnassia, the shape of basal leaves, the characteristics of petals (entire or flat, divided into lobes or filiform rays, respectively), and the shape of staminodes (i.e., number and depth of staminode branches, shape of staminode lobes, with globose glands at apex or not) were considered to be of great significance in species delimitation (
Morphological comparisons between Parnassia xinganensis (A1–A5) and P. guilinensis (B1–B5) collected from their type localities of Mao’er Mountain at altitudes of 1200 m and 580 m, respectively A1, B1 habitat A2, B2 flower A3, B3 calyces, staminodes and ovary A4, B4 petals A5, B5 variation of staminodes.
Type specimens of P. guilinensis and P. xinganensis deposited at IBK, as well as other Parnassia specimens collected from Mao’er Mountain, Xing’an County, Guangxi Province, China, preserved in GXMG, IBK, IBSC, KUN and PE (acronyms according to
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!).
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.
Flowering – late June to November; fruiting – August to December.
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.
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!).
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 (
We are grateful to the curators of GXMG, IBK, IBSC, KUN and PE for providing access to specimens; Dr. Li-Na Dong, Mr. Fang-Min Hu and Prof. Hui-Chun Du for their field assistance; Dr. Yu-Min Shu for sharing some Parnassia literature; and to Prof. Guang-Zhao Li for his comments on the manuscript. This work was supported by the National Natural Science Foundation of China (grants no. 41561014, 31900181).