Prunus wangii Q.L.Gan, Z.Y.Li & S.Z.Xu, 2022

Xu, Song-Zhi, Gan, Qi-Liang & Li, Zhen-Yu, 2022, A new species of Prunus subgen. Cerasus from Central China, PhytoKeys 199, pp. 1-7 : 1

Prunus wangii Q.L.Gan, Z.Y.Li & S.Z.Xu sp. nov.

Fig. 1

Diagnosis.

Prunus wangii Q.L.Gan, Z.Y.Li & S.Z.Xu is similar to P. clarofolia Schneid. and P. pseudocerasus Lindl., but the new species can be easily distinguished from the latter two species by its larger trees, densely and horizontally arranged lenticels, straight lateral veins of leaves, persistent brownish bracts, 2-lobed petals with narrowly triangular sinus and broadly ellipsoid fruits.

Type.

China, Hubei Province, Zhuxi County, Quanxi Town, Zhangjiashan Village , in mixed forest on hillside, alt. 700 m, 26 February 2021, Q.L. Gan 3237-1 (holotype: PE!; isotype: PE!)

Description.

Trees, deciduous, to 21 m tall (flowering well even when less than 6 m tall), DBH to 30 cm. Bark dark grey, lenticels distinct, transversely elliptic, densely arranged in horizontal lines; crown ovoid. Branchlets grey or taupe, sparsely pilose when young, later glabrate. Winter buds ovoid, ca. 2.5 mm long, internal bud scales brown, glabrous outside, densely pilose inside. Stipules linear, 6-8 mm long, with laciniate or lacerate and gland-tipped lobes, caducous. Leaves alternate, brownish-green when young; petiole 8-12 mm long, sparsely pubescent, lavender brown adaxially, longitudinally grooved; leaf blade elliptic or obovate, 5-11 cm long, 3-6.4 cm wide, base shallowly cordate, rounded or sometimes obliquely cuneate, base of blade or apical part of petiole with or sometimes without 1-3 purple discoid glands, margin biserrate and uniserrate, serrations acute, with a small apical gland, apex cuspidate or acuminate; adaxial surface deep green, glabrous, abaxial surface pale green, white pubescent along veins, margin ciliate; lateral veins 6-9 pairs, straight, veins slightly impressed on adaxially surface and raised abaxially. Inflorescences corymbose 4-6-flowered or umbellate 2-3-flowered; involucre green, orbicular-ovate, 2-5 mm long, 2-4 mm wide, abaxially glabrous, adaxially densely pilose; peduncle 2-11 mm long, subglabrous or sparsely white pubescent; bracts green, brownish when dry, fan-shaped, rarely linear, 2-7 mm long, 0.5-3.5 mm wide, proximal one larger, margin glandular-serrate, persistent in fruit. Flowers and leaves opening at same time (coetaneous) or nearly so. Pedicel 0.9-1.2 cm long, to 1.3-2 cm long in fruit, straight, thickened at apex, densely white pilose. Hypanthium campanulate, 5-6 mm long, 2.5-3 mm in diam., pilose outside; calyx lobes triangular, 2.5-3 mm long, margin entire, apex rounded or subacute, glabrous or pilose outside, at first patent, reflexed when flower fully expanded. Petals pink during early blooming, then white or slight pinkish tinged, broadly ovate, 7-11 mm long, 5-9 mm wide, apex 2-lobed, sinus narrowly triangular. Stamens 34-38, as long as or shorter than petals, glabrous, 6-11 mm long; filaments white; anthers dark yellow, broadly ellipsoid, 0.65-0.75 mm long. Ovary green, glabrous; style shorter than stamens, sparsely patent white-pilose below middle. Drupe broadly ellipsoid, 10-12 mm long, 8-10 mm in diam., glabrous, red at maturity, shiny, tasting sweet and sour. Stone flattened ovoid, 8-8.5 mm long, 5-5.5 mm wide, ca. 4 mm thick, fawn, surface almost smooth, ribbed on one side.

Phenology.

Flowering from late February to late March, flowers and leaves opening at same time (coetaneous) or nearly so; fruiting from April to May.

Distribution and habitat.

Prunus wangii is known from only two populations composed of ca. 20 individuals in Zhangjiashan Village, Quanxi Town and Tianbaozhaichachang, Tianbao Town, Zhuxi County. It grows sparsely in mixed forests on hillsides at elevations from 600 to 800 m. The main companion species include trees: Populus adenopoda Maxim., Liquidambar formosana Hance, Castanea seguinii Dode, Platycarya strobilacea Sieb. & Zucc., Pinus massoniana Lamb., Cunninghamia lanceolata (Lamb.) Hook., Prunus conradinae Koehne and Prunus subhirtella var. ascendens (Maxim.) E.H.Wilson; shrubs: Coriaria nepalensis Wall., Rubus lambertianus Ser., Rubus coreanus Miq., Lindera glauca (Sieb. & Zucc.) Bl. and Rosa banksiae var. normalis Regel; vines: Hedera nepalensis var. sinensis (Tobl.) Rehd., Lonicera japonica Thunb., Clematis florida Thunb. and Pueraria montana (Lour.) Merr.; herbs: Chrysanthemum indicum L., Miscanthus floridulus (Lab.) Warb. ex Schum & Laut. and Senecio scandens Buch.-Ham. ex D. Don; ferns: Cyrtomium fortunei J. Sm., Athyrium filix-femina (L.) Roth, Asplenium varians Wall. ex Hook. & Grev. and Pteris cretica var. nervosa (Thunb.) Ching & S. H. Wu.

Etymology.

The species is named in honour of Professor Wen-Tsai Wang (1926-), a taxonomist at the Institute of Botany, the Chinese Academy of Sciences, who has devoted over 60 years to taxonomic studies of Ranunculaceae, Gesneriaceae, Boraginaceae, Urticaceae and many other families and the floristic research in eastern Asia.

Vernacular name.

Wen Cai Ying Tao (Chinese).

Conservation assessment.

We found Prunus wangii only in the towns of Quanxi and Tianbao, Hubei Province and estimated the population size to be ca. 20 individuals. The provisional conservation status is Critically Endangered (CR), based on criterion D (number of mature individuals fewer than 50) ( IUCN 2022).

Economic uses.

There are more than 140 species of flowering cherries widely distributed in the Northern Hemisphere, but species blossoming in February are rare. Two species, P. pseudocerasus Lindl. and P. campanulata Maxim., have been used as important breeding materials of flowering cherries with early spring blooms since their introduction into Japan ( Ohwi and Ohta 1973; Ohba 2001; Wang 2014). Prunus wangii will provide a new breeding material for early flowering ornamental cherries. The timber of this species is hard and was used to make chopping blocks and furniture by the local people. The mature fruit is red, sweet or slightly bitter and is eaten by the local people.

Paratypes.

China. Hubei: Zhuxi County, Quanxi Town, Zhangjiashan Village, in mixed forest on hillside, alt. ca. 700 m, 11 March 2021, Qi-Liang Gan 3238 (PE!); the same locality, 21 April 2021, Qi-Liang Gan 3239-1, 3239-2 and 3239-3 (PE!); Zhuxi County, Tianbao Town, Tianbaozhaichachang, in mixed forest on hillside, alt. ca. 750 m, 11 March 2021, Qi-Liang Gan 3240 (PE!).

Figures

Figure 1. Prunus wangii sp. nov. A crown B trunk C bark D fruiting branches E leaf blades F petioles and glands G internal bud scales H involucres and bracts I inflorescence J pedicels and hypanthia K calyces L corolla M petals N ovary and style O fruits P seed.