Youngia hangii (Asteraceae, Crepidinae), a new species from Hubei, China Author Liu, Qun School of Life Sciences, Yunnan Normal University, Kunming 650092, Yunnan, China Author Huang *, Gui-Yun Rare Plants Research Institute of Yangtze River, Three Gorges Corporation, Yichang 443133, Hubei, China Author Zhang, Dai-Gui College of Biology and Environmental Sciences, Jishou University, Jishou 416000, Hunan, China Author Zhang, Jian-Wen https://orcid.org/0000-0002-4735-168X CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China Author Deng, Tao CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China dengtao@mail.kib.ac.cn Author Li 1, Zhi-Min School of Life Sciences, Yunnan Normal University, Kunming 650092, Yunnan, China text PhytoKeys 2021 2021-09-14 182 27 38 http://dx.doi.org/10.3897/phytokeys.182.71063 journal article http://dx.doi.org/10.3897/phytokeys.182.71063 1314-2003-182-27 3FF29E5A10635E7DA85D724B20963A96 Youngia hangii T. Deng, D.G. Zhang, Qun Liu & Z.M. Li sp. nov. Type . China . Hubei : Wufeng County , Renheping , 30°06'27"N , 110°16'31"E , karst cave of karst topography, 500-800 m alt., 5 August 2018 , Daigui Zhang & Qun Liu HAC 001 ( holotype KUN (KUN1511675); isotypes KUN (KUN1511676), JSU (HHE 3256)) . Description. Herbs, perennial, 20-35 cm tall. Taproot straight or slightly oblique, fleshy, with lateral roots (Fig. 2D ). Stems erect, branched from the base, with sparse white simple hairs; stem base ribbed, with 1 or 2 leaves similar to basal leaves. Basal leaves crowded at the caudex base; petiole 2-3 cm long; blade oblanceolate, 6-18 x 2-4 cm, both surfaces short pubescent with white hairs 0.1-0.3 mm long (pubescence more evident on veins), bipinnate to pinnatifid, apical lobe halberd-shaped, apex acute-acuminate, margin deeply lobed; lateral lobes 5-10 pairs, opposite or slightly skewed, irregularly halberd-shaped (lateral lobes tapering to the base, serrate, lowermost lobes narrowly triangular), often with 1-3 pairs of triangular or oblique-ovate lobes between lateral lobes. Synflorescence corymbiform; capitula 7-10. Involucre ampullate, 3-4 mm long, 3 mm in diameter. Phyllaries in 4 rows, greyish-green; outer phyllaries 5-7, ovoid-triangular, ca. 1 x 1 mm, apex acute; inner phyllaries 7-9, lanceolate, 2-4 x 0.5-1 mm, margin white-membranous, apex acute; florets 8-10, ligules 4-6 x 1-2 mm, teeth 0.2-0.4 mm long, tube 3-4 mm; anther tube ca. 2.5 mm long; style branches ca. 0.5 mm long. Outer achenes black, fusiform, 2 mm long, apex attenuate to shortly beaked and expanded again into the pappus disc; ribs 12-14; pappus white, bristles rough, 3 mm long; inner achenes similar to the outer ones, 2.5 mm long. Figure 1. Bayesian consensus tree of Youngia hangii and related species. The BP tree is constructed, based on the combined matrix of ITS and rps16 sequences. Numbers below branches are ML bootstraps and MP bootstraps and numbers above branches indicate Bayesian posterior probability. Youngia hangii is shown in bold. Figure 2. Youngia hangii T. Deng, D.G. Zhang, Qun Liu & Z.M. Li A habitat B population C habit D root E stems F, G leaves H-J capitula K, L floret ( A-E, H-J Photos by D.F. Zhang F, G, K, L Photos by Qun Liu D, E, J-M HAC001 (KUN)). Phenology. Flowering and fruiting April to October. Vernacular name. 五峰黄鹌菜 , wǔ fēng huanɡ an cai in Chinese Pinyin. Etymology. The species epithet honours Prof. Hang Sun (b. 1963), a Chinese botanist who has conducted research on plant taxonomy, floristics, biogeography and evolutionary biology and inspired many people through his work. He has also given a lot of support to the plant research work in Hubei. Distribution and habitat. Youngia hangii is known only from the type locality, Renheping in Wufeng Xian, Hubei, China; 500-1000 individuals are known along the edge of some small caves at the base of the karst hillside (Fig. 2A, B, C ); at altitudes of 500-800 m. Morphological assessment. Morphological characteristics suggest that Y. hangii is related to Y. rubida and Y. heterophylla owning 10-25 florets and resembles Y. rosthornii with bipinnately deeply partite leaves. The achenes of Y. hangii and Y. rubida are attenuated into a short beak, which is widened into the pappus disc. Several unique features including the shape, lobes and size of the leaves, the leaves with white simple hairs (Fig. 2E, F, G ; Fig. 3F, G ), phyllaries, number of florets and achenes differentiate Y. hangii from Y. rubida and Y. heterophylla (Table 1 ). Figure 3. Youngia hangii T. Deng, D.G. Zhang, Qun Liu & Z.M. Li A, B capitula C floret D habit E leaf with hairs F achene (drawing by Jianing Yang). Table 1. Comparison of morphological characteristics between Youngia hangii and related species.

Character				Y. hangii	Y. rubida	Y. heterophylla	Y. rosthornii
Basal leaf	shape			oblanceolate, bipinnately partite	oblanceolate, pinnately deeply or completely partite	elliptic or oblong lanceolate, pinnately deeply or completely partite	long elliptic, bipinnately deeply partite with a large apical part
	lobes		shape	apical lobes halberd-shaped, apex acute, with a tapered tip, margin middle to deep lobed; lowest lobes narrowly triangular	apical lobes triangle, apex acute, with a tapered tip, margin serrate; lowest lobes serrate	apical lobes elliptic, irregularly elliptic, ovate or lanceolate, apex acute, with a tapered tip, margin entire, almost entire or serrate; lowest lobes narrowly halberd	apical lobes triangular, apex acute, with a tapered tip, margin entire, almost entire or serrate; lowest lobes narrowly triangular
			number of lateral lobes	5-10 pairs	2-3 pairs	1-8 pairs	5-7 pairs
	size			6-18 x 2-4 cm	3-7 x 1.5-3 cm	13-23 x 6-7 cm	20 x 8 cm
	surface			with white pubescent hairs on both surfaces, especially dense on veins	glabrous on both surfaces	sparsely pubescent on both surfaces	glabrous on both surfaces
Phyllaries				4 rows	4 rows	4 rows	4 rows
Number of florets				8-10	13-15	11-25	20
Achenes		colour		black	red	brown-purple	brown-purple
		shape		fusiform, attenuated into a narrow neck, with a conical beak	fusiform, attenuated into a narrow neck, with a conical beak	fusiform, attenuated into a narrow neck, without a beak	fusiform, attenuated into a narrow neck, without a beak
		length		2 mm	2.8 mm	3 mm	3.5 mm
		ribs		12-14 ribs with small bristles	12 ribs with small bristles	14-15 ribs with small bristles	14-15 ribs with small bristles
Pappus				white, rough, 3 mm	white, rough, 3.5 mm	white, rough, 3-4 mm	white, rough, 3.5 mm

Phylogenetic analysis. The Bayesian tree showing PP support, ML bootstrap (LP) and MP bootstrap (BP) values for each clade are presented in Fig. 1 . The species in clade Ι form a monophyletic group with PP = 0.97, but LP are with weak support and BP are in conflict with PP and they were instead with "-" , respectively in Fig. 1 . Youngia hangii is nested within Clade I as sister to Y. rubida with strong support (PP = 1, LP = 83, BP = 88). Figure 4. Distribution of Youngia hangii in Hubei Province, China.