Prunus yunkaishanensis B.H. Wu, W.Y. Zhao & W.B. Liao, 2022

Wu, Bao-Huan, Zhao, Wan-Yi, Yang, Hai-Jun, Chen, Zhi-Hui, Li, You-Yu, Cui, Da-Fang, Liao, Wen-Bo & Kang, Ming, 2022, Prunus yunkaishanensis (Rosaceae), a new species from Guangdong, South China, Phytotaxa 541 (3), pp. 277-284 : 280-282

Prunus yunkaishanensis B.H. Wu, W.Y. Zhao & W.B. Liao , sp. nov. ( Figures 2 & 3 (G–I)).

Diagnosis: — Prunus yunkaishanensis is morphologically similar to P. phaeosticta and P. fordiana , but differs from the latter two species by its larger leaves with more pairs of lateral veins, shorter inflorescences with stout rachises, bracts persistent during anthesis and ovoid fruits.

Type:— CHINA. Guangdong: Gaozhou, Magui Town, Daxi Village , Qiecaiping ( Yunkai Shan area ), in valley, 22°14'59.85" N, 111°16’5.23” E, 700 m a.s.l., 1 November 2020 (fl.), B.H. Wu & W.Y. Zhao P20201562 (Holotype IBSC!; Isotypes IBSC!, SYS!) .

Description:— Small trees, 3–4 m tall. Bark reddish brown, with small lenticels. Branchlets reddish-brown, glabrous, with sparsely small lenticels. Winter buds ovoid. Stipules lanceolate, 0.3–0.5 cm long. Petioles glabrous, (0.2–)0.35–0.55(–0.8) cm long; leaf blades thinly coriaceous, oblong-oblanceolate to oblanceolate, rarely narrowly elliptic, 14–20 × 4.5–6.0 cm, base rounded, rarely slightly cordate or broadly cuneate, apex caudate, rarely acuminate or cuspidate, margin undulate or not, sparsely serrate with shallow acicular teeth or only serrate in upper half, rarely wholly entire, both surfaces glabrous, adaxially dark green, abaxially pale green, scatteredly punctate, with 1–2 nectaries at the leaf base (sometimes absence); lateral veins 13–18 pairs, adaxially impressed, abaxially prominent. Racemes solitary, in axils of extant or fallen leaves, 1–3.3 cm long, (1–)3–12 flowered, rachis stout, ca. 1.5 mm in diam., villous; involucre broadly ovate, 3–4 × 3–4 mm, glabrous, margin ciliate; bracts 3–4 × 2–3 mm, broadly ovate, glabrous, margin ciliate, persistent during anthesis; pedicel 1–3(–4) mm, villous; hypanthium shortly campanulate, 1.5–3 × 2.5–4 mm, outside villous, inside glabrous; sepals rounded-triangular, 1.0– 1.8 mm, outside villous, inside glabrous, margin ciliate; petals white, suborbicular, 1.5–2.0 mm long, glabrous, reflexed in blooming flowers; stamens ca. 20; filaments glabrous, 3–4 mm long, base adnate to calyx tube; anthers ca. 0.4 mm long; ovary glabrous, style 4–5 mm long, slightly longer or as long as stamens. Drupe ovoid, 1.5–1.8 × 0.75–0.90 cm, glabrous; endocarp prominently reticulately rugose.

Distribution and habitat:— Prunus yunkaishanensis is currently only known from Yunkaishan National Nature Reserve, western Guangdong, and only 10 individuals were discovered. It grows in the moist valley and forest margin at elevations of 650 to 800 m.

Phenology:—Flowering from October to November, fruiting from December to February (the ensuing year).

Etymology:—The specific epithet refers to the type locality, Yunkai Shan National Nature Reserve in Guangdong Province, China. The Chinese name of the new species is here given as 云开山桂ē (yún kāi shān guì yīng).

Additional specimens examined:— Prunus yunkaishanensis (paratypes): CHINA. Guangdong: Gaozhou, Daxi village, Qiecaiping , roadside, 22°14’59.85” N, 111°16’5.23” E, ca. 700 m a.s.l., 12 January 2020 (young fr.), Z.H. Chen, X.J. Zhang, S.Y. Lee & Y.L. Chen YKS-1288 (IBSC, SYS); ibid., 11 October 2020 (fl. bud), B.H. Wu, F. Ye & W.Y. Zhao P20201551 (IBSC); ibid., 27 December 2020 (fr.), B.H. Wu & X.Q. Wen P20201635 (IBSC); Gaozhou, Daxi village , Qiecaiping, Shatou, 22°15’0.57” N, 111°16’1.61” E, 704 m a.s.l., 11 October 2020 (fl. bud), B.H. Wu, F. Ye & W.Y. Zhao P20201549 (IBSC), P20201550 (IBSC), P20201552 (IBSC); ibid., 1 November 2020 (fl.), B.H. Wu & W.Y. Zhao P2020151557 (IBSC), P20201558 (IBSC), P20201559 (IBSC), P20201560 (IBSC), P20201561 (IBSC); Gaozhou, Daxi village , Qiecaiping, 22°14’52.55” N, 111°15’58.4” E, 724 m a.s.l., 11 October 2020 (fl. bud), B.H. Wu, F. Ye & W.Y. Zhao P20201553 (IBSC) .

Prunus fordiana : CHINA. Guangdong: Maoming , 23 July 1922, Y.X. Wang 9199 ( IBSC 0315405 ) ; Taishan , August 1903, Anonymous s.n. ( IBSC 0004380 ) ; Yangchun, Jinshan , 14 November 1935, C. Wang 38751 ( IBSC 0315448 ) ; Yu’nan, Guixulinchang , 600 m a.s.l., 2 November 1991, N. Liu et al. 2662 ( IBSC 0315463 ) . Guangxi: Baise , 25 September 1928, R.C. Ching 7658 ( PE 00589256 ) ; Dongxing, Dahao , 15 May 1959, P.C. Zhou 02803 ( PE 00589238 ) ; Fangchenggang, Naliang , 1-10 August 1936, W.T. Tsang 26627 ( IBSC 0315404 ) ; Hepu , December 1951, J.X. Zhong 809399 (IBK IBK00063124 ) ; Napo, Nongbu Valley , 1100 m a.s.l., 24 May 1989, Exped. Huanan 1055 ( IBSC 0315406 ) . Hainan: Precisely locality unknown, Department of Forestry 90687 ( IBSC 0315466 ) ; Baisha, Yinggeling , 29 March 1936, X.Q. Liu 25933 ( PE 00589241 ) ; Baoting, Xinglong , 5 April 1935, F.C. How 71653 ( IBSC 0315481 ) ; Baoting, Diaoluoshan , 22 November 1954, Exped. Diaoluoshan 2769 ( IBSC 0315472 ) ; Chengmai, Gudong Valley , 14 December 1932, C.L. Lei 291 ( PE 00589249 ) ; Danzhou, Nalianshan , 1 May 1928, W.T. Tsang 157 ( PE 00589246 ) ; Lingao, Baishishan , 14 June 1928, W.T. Tsang 695 ( PE 00589247 ) ; Lingshui, Jianshan , 3 May 1932, H. Fung 20182 ( PE 00589251 ) ; Sanya, Yazhou, Luopeng , 10 July 1933, F.C. How 71003 (IBK IBK00063125; PE 00589248); Wanning, Dalianling , 8 May 1961, Y. Zhong 3853 ( IBSC 0338152 ) .

Prunus phaeosticta : CHINA. Fujian: Nanjing, Liudoushan , 700 m a.s.l., G.D. Ye 2321 ( PE 00589474 ) ; Nanping, Xiayang , 150 m a.s.l., 1 November 1980, G.S. He 1307 ( PE 00589506 ) ; Sanming, Sanyuan , 26 April 1931, Y. Lin 210 ( PE 00589778 ) . Guangdong: Boluo, Luofushan , 23 December 1928, Y. Tsiang 1700 ( IBSC 0337987 ) ; Guangzhou, Baiyunshan , May 1970, H.F. Hance 6015 (A 00032444; GH 00032443); Maoming, Dapo, 17 August 1956, L. Deng 2395 ( IBSC 0338084 ) ; Ruyuan, Tixiashan , 20April 1934, S.P. Ko 54147 ( IBSC 0338000 ) ; Shixing, Nanmokeng , 300590 m a.s.l., 10 July 1958, L. Teng 6723 ( IBSC 0338009 ) ; Yangchun, Guchong , 800 m a.s.l., 19 May 1991, H.G. Ye and N. Liu 1776 ( IBSC 0315464 ) ; Yangshan, Wuyuanxiang , 950 m a.s.l., 2 June 1956, L. Teng 1211 ( PE 00589398 ) ; Zhuhai, Beijiandao , 111 m a.s.l., 4 June 2015, X.X. Huang et al. 18800 ( IBSC 0860099 ) . Guangxi: Rongshui, Jiuwanshan , 800 m a.s.l., 8 June 1958, S.H. Chun 14351 ( IBSC 0338165 ) . Guizhou: Ceheng, Yanjia , 600 m a.s.l., 29 May 2004, F.C. Wang 113 ( PE 01115985 ) ; Zhenfeng, Shaping , 550 m a.s.l., 1 June 2004, G.F. Wang 129 ( PE 01115987 ) . Hongkong: Dawushan , 16 April 1930, N.K. Chun 40710 ( PE 00589391 ) . Hunan: Hengshan, Shiruntan , 11 August 1948, Y. Liu 547 ( PE 00589727 ) ; Yizhang, Mangshan , 1200 m a.s.l., 14 September 1980, H.S. Liao 111 ( PE 00589503 ) ; Zhijiang , 25 May 1959, P.C. Tam 062535 ( PE 00589501 ) . Jiangxi: Ganzhou, Wuzhifeng , 433 m a.s.l., 2 June 2015, W.Y. Zhao et al. LXP-13-12365 (SYS SYS00177147 ) ; Jinggangshan, Wuzhifeng , 880 m a.s.l., 17 October 1958, J. Xiong 03127 ( PE 00589368 ) ; Lichuan , 25 June 1958, M.X. Nie and S.S. Lai 3078 ( PE 00589378 ) ; Taihe, Shuiwuxiang , 500 m a.s.l., 21 May 1959, S.S. Lai 0597 ( LBG 00010774 ) . Taiwan: Gaoxiong, Shanping , 1320 m a.s.l., 19 September 1991, T.G. Lammers 8497 ( PE 00589476 ) ; Taoyuan, Lalashan , 12 m a.s.l., 24 June 1987, S.Y. Lv 22166 ( PE 00589477 ) . Tibet: Medog , 1950 m a.s.l., 12 September 1974, Anonymous 2496 ( PE 00589443 ) . Yunnan: Funing, Longmen , 1000 m a.s.l., 2 May 1940, C.W. Wang 89075 ( HITBC 0008408 ) ; Shuangjiang, Mengku , 1950 m a.s.l., 11 April 2005, S.S. Zhou 2605 ( HITBC 0007842 ) ; Wenshan, Laojunshan , 1850 m a.s.l., 25 April 1993, Y.M. Shui 2089 ( PE 00995773 ) . Zhejiang: Kaihua, Dawu , 4 August 1958, Anonymous 29866 ( PE 00589363 ) ; Jiande , 28 June 1958, Anonymous 29366 ( PE 00589364 ) ; Taishun, Liguangxiang , 740 m a.s.l., 1 September 1958, S.R. Zhang 3789 ( PE 00589365 ) .

Figures

FIGURE 2. Prunus yunkaishanensis. A. Habitat. B. Habit. C. Portion of stem, showing its reddish-brown bark with small lenticels. D. Leaves, adaxial view. E. Stipules. F. Leaf nectaries at the base of leaf abaxial surface. G. Part of leaf abaxial surface, showing sparse punctation. H. Flower, showing reflexed petals that are shorter than stamens. I. Raceme, showing stout rachis and bracts persistent during anthesis. J. Flowering branch, showing racemes in axils of extant or fallen leaves. K. Bract, adaxial view. L. Endocarp, showing reticulately rugose surface. M. Fruiting branch with ovoid fruits.

FIGURE 3. Morphological comparison of Prunus phaeosticta, P. fordiana and P. yunkaishanensis. P. phaeosticta (A–C): A. Leaf blade with cuneate base; B. Inflorescence with slender rachis and soon caducous bracts; C. Infructescence with subglobose fruits. P. fordiana (D–F): D. Leaf blade with cuneate base; E. Inflorescence with slender rachis and soon caducous bracts; F. Infructescence with an ellipsoid fruit.P.yunkaishanensis (G–I): G. Leaf blade with rounded or slightly cordate base; H. Inflorescence with stout rachis and bracts persistent during anthesis; I. Infructescence with ovoid fruits. A, C from X.X. Huang et al. 18800 (IBSC 0860099); B from S. P. Ko 54147 (IBSC 0338000); D from Department of Forestry 90687 (IBSC 0315466); E from F.C. How 71653 (IBSC 0315481); F from N. Liu et al. 2662 (IBSC 0315463); G from B.H. Wu & W.Y. Zhao P20201562 (IBSC); H from B.H. Wu & W.Y. Zhao P20201558 (IBSC); I from B.H. Wu & X.Q. Wen P20201635 (IBSC).