Epimedium acuminatum Franch., Bull. Soc. Bot. France 33: 109. 1886

Xu, Yanqin, Liu, Linjian, Liu, Shaoxiong, He, Yiming, Li, Renqing & Ge, Fei, 2019, The taxonomic relevance of flower colour for Epimedium (Berberidaceae), with morphological and nomenclatural notes for five species from China, PhytoKeys 118, pp. 33-64 : 36-39

1. Epimedium acuminatum Franch., Bull. Soc. Bot. France 33: 109. 1886 Fig. 1

Epimedium komarovii H. Léveillé, Fedde Repert. Spec. Nov. Regni Veg. 7: 259. 1909. Type: CHINA. Guizhou: Pin-Fa, 1908, Cavalerie 954 (holotype: E00270388!).

Epimedium simplicifolium T.S.Ying, Acta Phytotaxon. Sin. 13: 51. 1975. Type: CHINA. Guizhou: Wuchuan, 9 May 1928, P. C. Tsoong 606 (holotype: PE01432137!; isotype: PE01432138!).

Epimedium chlorandrum Stearn, Kew Bull. 52: 660. 1997. Type: CHINA. Sichuan: Baoxing, cultivated in England, Hampshire, Kilmeston, Blackthorn Nursery, April 1996, Ogisu 94003 (holotype: K000340098!).

Type.

CHINA. Guizhou: 1858, Perny s.n. (holotype: P, barcode P02327614!; isolectotype: P, barcode P02327612!).

Description.

Herbs 20 –80(– 110) cm tall. Rhizome compact, sometimes long creeping, 2-8 mm in diam. Leaves basal and cauline, usually trifoliolate or occasionally unifoliolate; leaflets of trifoliolate leaves narrowly ovate or lanceolate, 3-19.8 × 1.5-8.9 cm, apex long acuminate, base cordate, lobes rounded or acute, those of the lateral leaflets very unequal; unifoliolate leaves ovate or broadly ovate, 8.7-20 × 6.8-11.5 cm, apex acuminate, base cordate, lobes equal, rounded or rarely acute; leaves leathery when mature, margin spinous-serrate, spines 1-2 mm long, adaxially deep green, glossy, abaxially glaucous, papillose, with dense or sparse shortly appressed stout bristle-like hairs and sometimes densely sericeous. Flowering stem with 2 trifoliolate opposite leaves, sometimes 3-whorled trifoliolate leaves or 2 opposite unifoliolate, rarely with 2 opposite leaves with one trifoliolate and the other unifoliolate, 3 whorled leaves with one trifoliolate and two unifoliolate or 3 whorled unifoliolate leaves. Panicle 6 –70(– 108)-flowered, 6-33 cm long, with lower peduncles loosely 2-5-flowered, glabrous or occasionally glandular-hairy. Pedicel 1-5 cm long. Flowers large, 3-5 cm in diam. Outer sepals 4, blunt, outer pair ovate-oblong, ca. 3 × 2 mm, inner pair broadly obovate, ca. 4.5 × 4 mm; inner sepals ovate-elliptic, 6-21 × 3-9 mm, apically acute, white, yellowish, pale rose or rose, petals pale yellow, yellow, pale violet, reddish-purple, purple-yellow, pale purple or purple. Petals curving outward, horn-shaped, much longer than inner sepals, 15-25 mm, tamping from the swollen but lamina-less base. Stamens 3-4 mm long; anthers yellow or green, ca. 2.5 mm long. Follicles oblong, ca. 20 mm long, style rostriform. Seeds numerous.

Distribution and habitat.

Epimedium acuminatum is one of the most widespread species in the genus, distributed in Sichuan, Guizhou, Chongqing, and northern Yunnan. Its large distribution area is predominantly characterised by mountain land. Epimedium acuminatum is often found on mountain slopes, forest edges or weedy slopes with elevations ranging from 270 m to 2400 m (Fig. 2 ).

Phenology.

Epimedium acuminatum flowers from April to June, and fruits from May to July.

Taxonomical remarks.

Before this study, flower colour variation in E. acuminatum had already been recognised. Overall, yellow (B. Y. Peng 47073, F. T. Wang 23329, D. Y. Peng 47070, W. P. Fang 802, Anon. 86, Z. X. Qu 1305, Q. H. Chen et al. 9411) or pale yellow (Sanxia Exped. 0821, X. B. Zhang 19), purple (G. H. Yang 54343, Sichuan Econ. Pl. Exped. 0030, K. J. Guan et al. 0273, Xiong & Z. L. Zhou 91045, Z. Y. Liu 15500, T. H. Tu 3116, S. Z. He 96410, S. W. Teng 0008, P. Zhao 807, Y. Tsiang 4994) or pale purple (P. Zhao 762, Jinfoshan Exped. 0330, Jinfoshan Exped. 0202, G. F. Li 60324), purple-whitish (T. T. Yu 312, Z. Z. Guo 403, J. M. Yuan 003 and J. M. Yuan 005, S. W. Tfng 90093, Z. S. Zhang et al. 401131), and white (K. J. Guan et al. 477, C. H. Li 97-301, K. Y. Lang 3002, K. J. Guan et al. 165) or whitish (Z. X. Qu 1057, Sanxia Exped. 0729 and Sanxia Exped. 0909) were the most frequently recorded flower colours. However, specific colours, for example, reddish (S. P. Pong 6108), yellowish purple (X. Y. He 4050; T. C. Pan & G. F. Wu 105), and pale purple-green (Z. Y. Wu 60) have also been examined from specimens. Colour differences among individuals of the same location have been slightly recorded, but both yellow and purple flowers were recorded in Sichuan Econ. Pl. Exped. 0013. Moreover, continuous variations from yellow to white and from yellow to pale reddish-purple were remarked by T. H. Tu 2763 and B. L. Guo 0608, respectively.

Two synonyms are included in E. acuminatum , namely E. simplicifolium and E. chlorandrum . There were only two specimens of E. simplicifolium for reference. The holotype (P. C. Tsoong 606) recorded yellow flowers with purplish red petals. Since these descriptions were based on flowers that are not fully open - the outer sepals soon falling - the outermost is formed of inner sepals. Therefore, the "yellow flower" actually is "yellow or yellowish inner sepals". Another specimen (S. Z. He 96410) recorded a purplish red flower, and the inner sepals spotted with purplish red. Epimedium chlorandrum has six specimens. Greenish inner sepals and pale yellow petals have been described in the holotype (Ogisu 94003). Pale yellow inner sepals and petals were recorded in B. L. Guo 0540 and B. L. Guo 0607 while B. L. Guo 0606 described the colour variation of inner sepals as anything from pale yellow to pale purplish red. And B. L. Guo 0608 also described both inner sepals and petals from pale yellow to pale purplish red.

Based on a field survey at the population level, we observed more extensive and continuous colour variation from pale yellow to dark purple (Fig. 1 ). Pure white flow ers have not been observed, but the pale yellow and whitish are very close to white. We therefore speculate that the white flowers described in the specimens might represent pale yellow or whitish flowers instead. Regarding the yellow and purple flowers, there was abundant colour variation among populations as well as among individuals. For example, yellow ranged from pale yellow to yellow, while purple ranged from pale violet or reddish-purple to purple and dark purple. Moreover, there were also many transitions between yellow and purple.

For E. acuminatum , the populations that showed uniform colour (yellow or purple) were excluded from the illustration in this study. We mainly focused on the populations that presented colour variation (Fig. 1 ). For example, SCMP showed mainly yellow flowers; only one out of the 30 individuals presented diverse colour, with a yellow spur tinged with a ray of rose inside the base of the petals. SCSL mainly had yellow flowers; parts of individual flowers showed pale yellow, and one individual presented purple-yellow at the base of the petals. CQNC primarily displayed yellow flowers; several individuals revealed a rose margin at the base of the petals, and one individual revealed reddish-purple flowers. SCSS was the most special population with 20 individuals had purple flowers while the rest (10 individuals) had yellow flowers. Moreover, SCSS was the only population for which the colour showed a continuous variation from yellow to purple. The flowers of SCEM and SCYJ were mainly with purple flowers, and purple-yellow occasionally (Fig. 1 ). In the above populations, SCMP and SCSS were E. chlorandrum .

Combing the geographical distribution of specimens (both field and herbarium specimens) and their flower colour variation of E. acuminatum , we found an interesting result (Fig. 2 ). Geographic variation in flower colour pattern within E. acuminatum showed a north-south geographic trend. The specimens from the northern area of its distribution mainly have yellow flowers, while the southern ones usually have purple flowers. The polymorphism of flower colour is mainly concentrated in the northwest of its distribution area.

In addition, the number and arrangement of the stem-leaves were significantly diverse in E. acuminatum . It commonly showed 2 trifoliolate opposite leaves, sometimes 3-whorled trifoliolate leaves (G. F Li 60514, Y. Tsiang 4994) or 2 opposite unifoliolate (S. Z. He 96410, P. C. Tsoong 606), rarely with 2 opposite leaves with one trifoliolate and the other unifoliolate (J. H. Xiong 30469), 3 whorled leaves with one trifoliolate and two unifoliolate (J. H. Xiong 30469) or 3 whorled unifoliolate leaves.

Additional specimens examined.

CHINA. Sichuan: Chengxiang, Tianquan, 1100-1200 m, 24 March 1983, B. Y. Peng 47070 and B. Y. Peng 47073 (CDBI, yellow flower); Jiulaodong, Mt. Emei, 1800 m, 02 May 1957, G. H. Yang 54343 (PE, KUN, HIB, NAS, purple flower); Lianhuashi, Mt. Emei, 1950 m, 11 May 1964, K. J. Guan et al. 477 (PE, white flower); Mt. Emei, 1100 m, 11 June 1933, S. P. Pong 6108 (PE, reddish flower); Mt. Emei, 1050 m, 13 March 1997, C. H. Li 97 - 301 (PE, white flower); Mt. Emei, 900 m, 16 April 1932, T. T. Yu 312 (N, purplish white flower); Mt. Emei, 2000 m, 15 July 1931, F. T. Wang 23329 (PE, yellow flower); Mt. Emei, 900 m, 16 April, T. T. Yu 312 (PE, purplish white flower); Mt. Emei, 1700 m, 27 May 1959, Z. Z. Guo 403 (PE, purplish white flower); Mt. Emei, 1952, J. H. Xiong 30469 (PE, 3 whorled leaves with one trifoliolate and two unifoliolate; IBSC, 2 opposite leaves with one trifoliolate and the other unifoliolate); Mt. Emei, 1049 m, 4 April 2015, Y. Q Xu & S. X. Liu 2015029 (JXCM, mainly purple flower); Mt. Emei, 1110 m, 10 April 2017, Y. M. He et al. 2017006 (JXCM, purple flower); Biexiandong, Jiang’an, 270 m, 5 April 1964, K. Y. Lang 3002 (PE, white flower); Wuzhuang, Hongya, 1150 m, 20 April 1959, Sichuan Econ. Pl. Exped. 0013 (SM, yellow and purple flower); Muping, Baoxing, 13 May 2005, B. L. Guo 0540 (IMD, pale yellow flower); Dachuan, Lushan, 1484 m, 4 May 2006, B. L. Guo 0606 (IMD, yellow flower); Youzha, Qionglai, 4 May 2006, B. L. Guo 0607 (IMD, pale yellow flower); Dachuan, Lushan, 1484 m, 4 May 2006, B. L. Guo 0608 (IMD, from yellow to pale reddish-purple); Shangli, Ya’an, 862 m, 7 April 2015, Y. Q Xu & S. X. Liu 2015027 (JXCM, yellow flower); Siping, Yingjing, 1448 m, 8 April 2015, Y. Q Xu & S. X. Liu 2015026 (JXCM, mainly purple flower); Fubao, Hejiang, 723 m, 10 April 2016, S. X. Liu & J. X Zhu 2016007 (JXCM, purple flower); Dazhubao, Mabian, 1147 m, 13 April 2016, S. X. Liu & J. X Zhu 2016008 (JXCM, purple flower); Dachuan, Lushan, 1192 m, 15 April 2016, S. X. Liu & J. X Zhu 2016009 (JXCM, yellow flower); Dachuan, Lushan, 1534 m, 16 April 2016, S. X. Liu & J. X Zhu 2016010 (JXCM, yellow flower);Youzha, Qionglai, 1067 m, 16 April 2016, S. X. Liu & J. X Zhu 2016011 (JXCM, yellow flower); Nanbao, Qionglai, 1468 m, 16 April 2016, S. X. Liu & J. X Zhu 2016012 (JXCM, yellow flower); Lingguan, Baoxing, 1068 m, 18 April 2016, S. X. Liu & J. X Zhu 2016014 (JXCM, yellow flower); Shuangshi, Lushan, 928 m, 11 April 2015, Y. Q. Xu & S. X. Liu 2015024 (JXCM, purple flower and yellow flower); Baoxing, cultivated at ENGLAND. Hampshire: Kilmeston, Blackthorn Nursery, April 1996, Ogisu 94003 (holotype, K). Chongqing: Baiwuping, Nanchuan, 850 m, 16 April 1957, G. F. Li 60514 (IBSC, KUN, NAS, 3-whorled trifoliolate leaves, reddish-purple flower); Tianxing, Nanchuan, 899 m, 27 March 2015, Y. Q Xu & S. X. Liu 2015035 (JXCM, yellow flower); Nanchuan, 1500-1800 m, 16 May 1928, W. P. Fang 802 (PE, IBSC, N, yellow flower); Xiaohe, Nanchuan, 1000 m, 10 May 1985, Z. Luo 0033 (CDBI); Mt. Jinfo (Jinfoshan), Nanchuan, 1700-1900 m, 13 April 1964, K. J. Guan et al. 0273 (CDBI, PE, purple flower); Mt. Jinfo (Jinfoshan), Nanchuan, 1550 m, 28 May 1957, J. H. Xiong & Z. L. Zhou 91045 (KUN, purple flower); Mt. Jinfo (Jinfoshan), Nanchuan, 880 m, 25 May 1935, X. Y. He 4050 (NAS, yellowish purple flower); Hetaoping, Mt. Jinfo (Jinfoshan), Nanchuan, 28 May 1935, X. Y. He 4148 (NAS, whitish flower); Hetaoping, Mt. Jinfo (Jinfoshan), Nanchuan, 28 April 1935, X. B. Zhang 19 (NAS, pale yellow flower); Mt. Jinfo (Jinfoshan), Nanchuan, 3 June 1935, Anon. 86 (NAS, yellow flower); Yangyuping, Mt. Jinfo (Jinfoshan), Nanchuan, 1800 m, 14 May 1986, Jinfoshan Exped. 0330 (PE, pale purple flower); Mt. Jinfo (Jinfoshan), Nanchuan, 720 m, 2 April 1996, Z. Y. Liu 15500 (PE, purple flower); Mt. Jinfo (Jinfoshan), Nanchuan, 1200 m, 2 June 1935, Z. X. Qu 1057 (PE, IBSC, whitish flower); Daheba, Mt. Jinfo (Jinfoshan), Nanchuan, 1020 m, 8 April 1964, K. J. Guan et al. 165 (PE, white flower); Fenghuangsi, Nanchuan, 2050 m, 12 June 1935, Z. X. Qu 1305 (PE, yellow flower); Delong, Nanchuan, 1500 m, 12 May 1986, Jinfoshan Exped. 0202 (PE, pale purple flower); Nanchuan, 4 April 1933, T. H. Tu 2763 (PE, yellow-white flower); Nanchuan, 1900 m, 22 May 1933, T. H. Tu 3116 (PE, purple flower); Fangheba, Nanchuan, 550 m, 5 April 1957, G. F. Li 60324 (PE, pale purple flower); Mt. Jinyun (Jinyunshan), Beibei, 700 m, 4 April 1963, T. C. Pan & G. F. Wu 105 (PE, yellowish purple flower); Wangerbao Nature Reserve, Wanzhou, 977-1221 m, 25 April 2008, Sanxia Exped. 0729 and Sanxia Exped. 0909 (PE, whitish flower); Longju, Wanzhou, 981-1143 m, 27 April 2008, Sanxia Exped. 0821 (PE, pale yellow flower); Simian, Jiangjin, 1200 m, 16 April 1959, Sichuan Econ. Pl. Exped. 0030 (KUN, NAS, purple flower); Mawu, Fuling, 935 m, 7 April 2016, S. X. Liu & J. X Zhu 2016005 (JXCM, yellow flower); Chashanzhuhai, Yongchuan, 762 m, 9 April 2016, S. X. Liu & J. X Zhu 2016006 (JXCM, yellow flower). Guizhou: Fengyi, Zhengan, 700-1000 m, May 1992, Q. H. Chen et al. 9411 (HGAS, yellow flower); Fengyi, Zhengan, 700 m, 1 June 1977, J. M. Yuan 003 and J. M. Yuan 005 (HGAS, purple-whitish flower); Huajiang, 1100 m, 1 April 1987, P. Zhao 762 (HGAS, pale purple flower); Anshun, 25 May 1935, S. W. Teng 0008 (IBSC, purple flower); Liuchongguan, Guiyang, 1300 m, 21 April 1987, P. Zhao 807 (HGAS, purple flower); Maoshajing, Guiyang, 16 April 1936, S. W. Tfng 90093 (IBSC, purple-whitish flower); Tongzi, 20 May 1930, Y. Tsiang 4994 (PE, purple flower, 3-whorled trifoliolate leaves); Tuanlong, Yinjiang, 1090 m, 10 April 1964, Z. S. Zhang et al. 401131 (PE, purple-whitish flower); Shuikousi, Guiyang, 1400 m, 16 March 1959, Qiannan Exped. 42 (PE, KUN, reddish-purple flower); Suiyang, 1100 m, 10 April 1994, S. Z. He 96410 (PE, 2 opposite unifoliolate leaves, purple flower); Longdong, Wuchuan, 9 May 1928, P. C. Tsoong 606 (PE, KUN, IBSC, 2 opposite unifoliolate leaves); Nanlong, Kaiyang, 986 m, 28 March 2016, S. X. Liu & J. X Zhu 2016002 (JXCM, purple flower); Hekan, Yanhe, 637 m, 1 April 2016, S. X. Liu & J. X Zhu 2016003 (JXCM, purple flower); Fengyi, Zhengan, 792 m, 4 April 2016, S. X. Liu & J. X Zhu 2016004 (JXCM, purple flower). Yunnan: Shuanghe, Weixin, 1480 m, 3 June 1960, P. Di 1076 (KUN); Chaotianma, Yiliang, 1973, Z. Y. Wu 60 (KUN, pale purple-green flower).

Figures

Figure 1. The flower colour variations of different populations of E. acuminatum. A SCMP, mainly yellow B SCSL, mainly yellow, occasionally purple-yellow at the base of petals C CQNC, mainly yellow, occasionally rose-purple D SCSS, from yellow to purple E SCEM, mainly purple, occasionally purple-yellow F SCYJ, mainly purple, occasionally purple-yellow G Individual with yellow flowers H Individual with purple-yellow flowers I Individual with purple flowers.

Figure 2. Geographical variation in flower colour patterns within E. acuminatum. The circles and boxes represent wild populations and herbarium specimens, respectively. The colour of the circles and boxes represent flower colour. The 19 population codes are shown in Table 1. The left area of the red dotted line is western China. The information of 23 representative herbarium specimens is as follow: 1. B. Y. Peng 47070; 2. B. L. Guo 0540; 3. B. L. Guo 0608; 4. B. L. Guo 0607; 5. Sichuan Econ. Pl. Exped. 0013; 6. F. T. Wang 23329; 7. G. H. Yang 54343; 8. K. Y. Lang 3002; 9. Sichuan Econ. Pl. Exped. 0030; 10. T. C. Pan & G. F. Wu 105; 11. Sanxia Exped. 0729; 12. Sanxia Exped. 0821; 13. K. J. Guan et al. 0273; 14. X. B. Zhang 19; 15. Jinfoshan Exped. 0202; 16. Q. H. Chen et al. 9411; 17. J. M. Yuan 003; 18. Z. S. Zhang et al. 401131; 19. Y. Tsiang 4994; 20. S. Z. He 96410; 21. P. Zhao 807; 22. S. W. Teng 0008; 23. Z. Y. Wu 60.