Dryopteris wulingshanensis J.P.Shu, Y.H.Yan & R.J.Wang, 2021

Shu, Jiang-Ping, Liu *, Zi-Yue, Gu, Zhi-Rong, Chen, Li-Jun, Wei, Hong-Jin, Zhou, Xi-Le, Yan, Yue-Hong & Wang, Rui-Jiang, 2021, Dryopteris wulingshanensis (Dryopteridaceae), a new species from Hunan, China, PhytoKeys 185, pp. 17-26 : 17

Dryopteris wulingshanensis J.P.Shu, Y.H.Yan & R.J.Wang sp. nov.

Figs 3 , 4 武陵山鳞毛蕨

Type.

China. Hunan: Wulingshan Mountains Zhongli Grand Canyon , Sangzhi County, Zhangjiajie City. 29°39'10.08"N, 110°37'04.29"E, 900 m alt., 26 June 2021, Y.-H. Yan & Z.-R. Gu, YYH24468 (holotype, IBSC; isotypes, NOCC!, CSH!,PE!) .

Diagnosis.

The morphology of D. wulingshanensis was intermediated between D. jishouensis and D. gymnophylla , but more similar to the former. Dryopteris wulingshanensis and D. jishouensis both grow in alkaline soil, but the former’s fronds are ovate, length/width 1.3-1.6 times, tripinnate to quadripartite; the latter’s fronds are ovate-lanceolate to triangular-lanceolate, length/width 1.7-2.0 times or more, bipinnate to tripinnatisect. Dryopteris gymnophylla grows in acidic soil, the fronds are pentagonal, usually length/width 1-1.2 times, tripinnate to quadripinnnatisect (Fig. 2 , Table 2 ).

Description.

Rhizome short-creeping, apex scaly; scales dark brown, lanceolate, margin entire or 1-2 dentate at base. Frond approximate, (40-)65-70 cm; stipe (23-)31-36 cm, medial diameter 1.5-2 mm, basal scales similar to rhizome scales, antrorse, glabrous, stramineous to brown-stramineous, ventrally grooved; lamina ovate, (19-)32-36 × (12-)19-28 cm, about 1.3-1.6 times as long as wide, base round or cordate, apex acuminate, tripinnate to quadripartite (premature lamina only bipinnate to tripinnatisect); pinnae 6-8 pairs, oblique, distant, falcate, stipitate, basal pair longest and largest, opposite to nearly opposite, significantly falcate, stipe (1.2-)3-4.5(-7) cm, deltate-lanceolate, (8-)12-23 × (3.6-)7-11 cm, apex long-acuminate, base broad-cuneate to round, asymmetric, basiscopic pinnules longer than acroscopic pinnules, suprabasal pinnae with pinnules similar; pinnules 7-8 pairs, discrete, oblique to explanate, falcate, base broadly cuneate, pedicellate, basiscopic ones largest, (3-)5-10 × (1.5-)2.2-4 cm, stipe (1.5-)4-9 mm, trigonal oblong, apex obtuse, ultimate pinnules (lobe) 7-10 pairs, oblique to explanate, trigonal oblong, basiscopic ones longer than acroscopic ones, exstipitate, round-obtuse, base broad-cuneate, connate, pinnatifid to partite, (9-)14-20 (4)8-10 mm; lobes 2-7 pairs, 1.5-2 mm wide, oblong, entire, round, others ultimate pinnules lobate to pinnatifid or crenate, base broad-cuneate to decurrent; other pinnae decrescent, opposite to alternate, trigonal lanceolate to oblong lanceolate; rachis and costa glabrous, stramineous, adaxially sulcate, lamina papyraceous, glabrous; veins pinnate, single or dichotomous; sori round, on apices of veinlets, nearly incision; indusia orbicular-reniform, margin premorse, brown, persistent.

Additional specimens examined (paratypes).

China. Hunan: Pangu Peak, Dehang Scenic Area, Jishou City , Xiangxi Tujia and Miao Autonomous Prefecture. 28°20'50.046"N, 109°34'34.522"E, 914 m alt., 26 Jun 2016, X.-L. Zhou et al. ZXL6320 - 1, ZXL6320-3 (CSH!); Tianmenshan Scenic Area , Zhangjiajie City. 5 April 2016, H.-J. Wei et al. JSL3926, JSL3935 (CSH!) .

Distribution and habitat.

Dryopteris wulingshanensis is endemic to the Wulingshan mountains in Jishou and Zhangjiajie Cities, Hunan, China. It is epipetric in limestone crevices at an elevation of 700-1000 m in evergreen and deciduous broad-leaved mixed forest. The associated ferns include: Cheilanthes patula Baker, Cyrtomium fortunei J. Sm., Cyrtomium nephrolepioides (Christ) Copel., Lemmaphyllum drymoglossoides (Baker) Ching, Polystichum tsus-simense (Hook.) J. Sm., Pronephrium penangianum (Hook.) Holttum, Pyrrosia petiolosa (Christ) Ching and Woodwardia unigemmata (Makino) Nakai and associated seed plants include: Celtis sinensis Pers., Choerospondias axillaris (Roxb.) B.L. Burtt & A.W. Hill, Davidia involucrata Baill., Ficus sarmentosa var. Ficus sarmentosa henryi (King ex Oliv.) Corner, Hydrangea strigosa Rehder, Loropetalum chinense (R. Br.) Oliv., Mallotus philippinensis (Lam.) Muell. Arg., Miscanthus sinensis Andersson, Platycarya strobilacea Siebold & Zucc., Rhus chinensis Mill. and Viburnum cylindricum Buch.-Ham. ex D. Don.

Etymology.

The specific epithet " Dryopteris wulingshanensis " is derived from the name of type locality Wulingshan Mountains, where the new species is found.

IUCN Conservation Assessment.

EN(B1ab(iii)). Dryopteris wulingshanensis is only known from three locations of Wulingshan Mountains in Jishou and Zhangjiajie Cities, Hunan, China. Based on its restricted geographic range, small populations and few individuals, Dryopteris wulingshanensis should be considered endangered under the IUCN Red List criteria ( IUCN 2019).

Figures

Figure 2. Morphological comparison amongst Dryopteris wulingshanensis, D. jishouensis and D. gymnophylla A-C D. jishouensis (type locality, Hunan A plants and habitats B stalks of basal pinnae C scales at base of stipe) D-F D. wulingshanensis (Zhangjiajie, Hunan D plants and habitats E stalks of basal pinnae F scales at base of stipe) G-I D. gymnophylla (Zhejiang G plants and habitats H stalks of basal pinnae I scales at base of stipe).

Figure 3. Dryopteris wulingshanensis J. P. Shu, Y. H. Yan & R. J. Wang A habit B pinnule with sori C scale at base of stipe D sporangium E spore (drawn by Li-Jun Chen, based on the type material at IBSC).

Figure 4. The habitat and morphological characters of Dryopteris wulingshanensis J. P. Shu, Y. H. Yan & R. J. Wang A habitat B lamina C basal pinna D sori E rhizome F base of stipe G spore (Left distal pole, Right proximal pole) H sporangium I scale.