Premna yunnanensis Smith (1916: 120)

Tan, Yunhong, Chen, Yongjun & Li, Bo, 2016, New synonyms for Premna yunnanensis (Lamiaceae) in China, Phytotaxa 283 (2), pp. 196-200 : 196-198

Premna yunnanensis Smith (1916: 120) . Figs. 1 & 2 .

Type:— CHINA. Yunnan: Lijiang County, Tong Shan (Dong Shan Town), Yangze bend, open dry situations amongst rocks, elev. 2700– 3050 m, 1 September 1913, G. Forrest 11240 (holotype E!, isotypes A!).

Celastrus yunnanensis Léveillé (1915: 32) . Type:— CHINA. Yunnan: Kiao-Kiao (Qiaojia County), rockies, pied de moux, elev. 400 m, June 1911, E.E. Maire, s.n. (holotype E!, isotypes A!, NY!).

Premna anthopotamica Handel-Mazzetti (1921: 231) , syn. nov. Type:— CHINA. Kweitschou (Guizhou Province): Ad viam Tschenning Huang tsauba in convalle fluminis Hoadjiau-ho in tergo rupestri ad vicum Falang, elev. 900 m, 20 June 1917, H.R.E. Handel-Mazzetti 10381 (holotype WU!, isotypes A!, W!).

Premna parvilimba P’ei (1932: 62), syn. nov. Type: as Celastrus yunnanensis Léveillé.

Premna pilosa P’ei (1932: 66). Type:— CHINA. Yunnan: Melliers de San-Kia, elev. 2600 m, no specific date, E.E. Maire 24 (holotype A!).

Premna steppicola Handel-Mazzetti (1936: 902) , syn. nov. Type:— CHINA. Yunnan: Steppen zwischen Hsindschwang und Hwaping (Djiuyaping) in der str. St. am Yangtse e von Yungbei, elev. 1400–1500 m, 31 October 1916, H.R.E. Handel-Mazzetti 13017 (holotype WU!, isotype W!).

Premna subcapitata Rehder (1917: 458) , syn. nov. Type:— CHINA. Western Szcch’uan (now Sichuan Province): without precise locality, cliffis, elev. 1200 m, June 1903, E.H. Wilson 3761 (holotype A!, isotype K!).

Illustrations:— Wu (1977: 432, Plate 102, 14–16); P’ei & Chen (1982: 106, Fig. 56, as P. steppicola ;); Wu & Peter (1998: 60, Fig. 60, 1–3, as P. steppicola ).

Distribution, habitat:— This species is endemic to southwest China, and distributed mainly around the Jinsha Jiang

River ( Fig. 3 ) in northwest and northeast Yunnan to southwest Sichuan, and extending to West Guizhou and some highlands of west Sichuan. It frequently occurs in the edge of mixed secondary forests along the vicinity of Jinsha Jiang valley, sometimes in the mixed forests on mountain slopes or among rocks.

Notes:— During the naming of P. anthopotamica , the author did not compare the species with any other described taxa of the genus, hence no diagnostic characters were presented. Later P. anthopotamica was recognized by P’ei (1932) based on its densely pubescent leaves with crisped appressed hairs beneath, and glabrous but glandular above. However, while revising the genus Premna , P’ei & Chen (1982) did not include P. anthopotamica in the Flora Reipublicae Popularis Sinicae. Later, Chen & Gilbert (1994) followed the same criteria for the Flora of China. During the examination of type specimens of P. anthopotamica and consulting the protologue, it is found that P. anthopotamica is closely identical to P. yunnanensis . The diagnostic characters noted by P’ei (1932) are also the same to those of P. yunnanensis . Thus P. anthopotamica is reduced to P. yunnanensis as synonym.

Premna steppicola when described was annotated as different to P. parvilimba only in leaf shape. The leaf blades of P. steppicola are frequently widely ovate with subrounded bases, while those of P. parvilimba [= Celastrus yunnanensis Léveillé (1915: 32) ; P’ei (1932)] are lanceolate to ovate-lanceolate with rounded bases. Subsequently, P’ei & Chen (1982) and Chen & Gilbert (1994) recognized the comparison but none of them have taken P. yunnanensis into consideration. In fact, P. parvilimba differs from P. yunnanensis having only smaller leaves, and the species is known only from the type specimens. The type locality of the species has been visited twice during 2010 and 2012 and we found a population of P. yunnanensis instead. Some individuals in dry and rocky habitat are dwarf and have relatively small leaves, which are superficially similar to the type specimens of P. parvilimba . Therefore, it is presumed that P. parvilimba is simply a dwarf form of P. yunnanensis growing in rocky habitat. Moreover, further investigations of herbarium specimens indicate that the leaf shape of P. steppicola falls well within the variation range of P. yunnanensis . Hence, C. yunnanensis , P. parvilimba and P. steppicola are placed under P. yunnanensis .

Premna pilosa was described with the note that it is closely related to P. subcapitata . The only difference is that P. pilosa have larger inflorescences with more flowers than P. subcapitata . However, Wu (1977) thought that the two species cannot be distinguished clearly by this character only and therefore reduced P. pilosa to a synonym of P. subcapitata . This proposal was followed by P’ei & Chen (1982) and Chen & Gilbert (1994). Wu (1977) stated that P. subcapitata is most similar to P. yunnanensis but differs from the later in having larger leaves and longer petioles, whereas P’ei & Chen (1982) noted that P. subcapitata can be distinguished from P. yunnanensis by its fruiting calyces longer than fruit, corolla yellowish and pubescent outside. However, from the protologues and examination of type specimens, it is found that the corollas of both species are sparsely to densely hirsute and golden glandular, and the calyces in both species ca. 4 mm in length. The protologue of P. yunnanensis clearly noted that flowers on the holotype (G. Forrest 11240) are pale rose, while pale yellow (G. Forrest 10527) or dull green (G.Forrest 10351) on two paratypes. After critical examination of types as well as specimens cited or identified by P’ei or Chen, we found that these differences are completely artificial and there are no any consistent differences between P. subcapitata and P. yunnanensis . In fact, P’ei or Chen had failed to make stable identifications for the same collection. For example, one specimen of Y.C. Yang 3956 deposited in PE was identified as P. yunnanensis by P’ei in March 1959, while its duplicate deposited in NAS was identified as P. subcapitata by the same author. Another collection, C.C. Hsieh 41764 was noted as P. subcapitata by Chen in September 1977, while the duplicate in PE was identified as P. yunnanensis in March 1978, by the same author too. So it is concluded that P. subcapitata and P. yunnanensis are conspecific, and therefore P. pilosa and P. subcapitata were here placed under P. yunnanensis .

Additional specimens examined:— CHINA: Sichuan Province: E’bian County , 14 October 1939, T.N. Liou & C. Wang 1430 ( PE!) ; E’bian County, Wanshousi Temp , 18 August 1939, Z.W. Yao 4623 ( NAS!, PE!) ; E’meishan County, E’meishan Mountain , 17 October 1938, T.N.Liou 10157 ( PE!) ; Luding County, Daduhe River , 29 June 1951, Y.W. Cui 4146 ( PE!) ; Luding County, Daduhe River , 22 May 1974, Luding Exp. 6812 ( CDBI!, PE!) ; Luding County, Dewei Town , 7 August 2010, E.D. Liu 2617 ( PE!) ; Luding County, Erlangshan Mountain , 11 June 1963, X.L. Jiang & J.H. Xiong 34392 ( IBK!, PE!) ; Luding County, 11 July 1951, W.G. Hu & Z. He 10323 ( PE!) ; Luzhou County, Mujiaogou , 16 September 1938, T.P. Wang 9740 ( PE!, WUK!) ; Kangding County, 15 September 1959, Y.C. Yang 3956 ( PE!, NAS!) ; Kangding County, Jiangzui Town , 3 May 1974, Sichuan Forest Exp. 05269 (CBDI!, PE!) ; Miyi County, October 1982, D. Liu 23990 ( CBDI!) ; Muli County, 2 August 1960, G.M. Fen 638 ( CBDI!) ; Muli County, Chabuli Town , 5 September 1983, Qinghai-Tibet Exp. 13598 ( KUN!) ; Shimian County, Tianwan Town , 8 July 1980, Q.Q. Wang & Z.A. Liu 22618 (CBDI!, IBSC!, WUK!) ; Shimian County, Ximagu , 1955, C.C.Hsieh 40733 ( IBSC!, WUK!) ; Tianquan County, 20 August 1982, D.Y. Peng 46329 ( IBSC!) ; Yanyuan County, 14 July 1983, Anonymous 21 ( HITBC!) ; Yanyuan County, Maoniushan Mountain , 10 June 1960, S. Jiang 5952 ( PE!) ; Yunnan Province: Binchuan County, Dawang Temple , 8 September 1933, Anonymous 2431 ( PE!) ; Fengqing County, Hsiaopingkai , 15 May 1938, T.T. Yu 15883 ( KUN!, PE!) ; Lijiang County, Shigu Town , 8 June 1981, Qinghai-Tibet Exp. 396 (HITBC!, KUN!, PE!) ; Lijiang County, Shigu Town , 4 July 1960, S. Jiang 9682 ( KUN!, PE!) ; Lijiang County, Dajubei Town , 18 August 1962, Zhongdian Exp. 1252 ( PE!) ; Lijiang County, Hutiaoxia Town , 20 July 1981, Anonymous s.n. ( PE!) ; Lijiang County, Xueshandagu , 26 August 1942, K.M. Feng 9173 ( KUN!, PE!) ; Lijiang County, Northwest of the Yangtze bend, 1 July 1913, G.Forrest 10351 ( PE!) ; Zhongdian County, Haba Town , 20 September 1962, Zhongdian Exp. 2224 ( KUN!, PE!) ; Zhongdian County, Baidi Village , 10 July 1963, Zhongdian Exp. 3323 ( KUN!) ; Zhongdian County, Haba Snow Mountain , 2 July 1963, Zhongdian Exp. 3005 ( KUN!) .

Figures

FIGURE 1. Premna yunnanensis. A. habit and habitat; B. a branchlet with inflorescence; C. corolla; D. fruits. Photographs A, B, D. from Shigu Town, Lijiang County, Yunnan Province, China by B. Li, C. from Hutiaoxia Town of the same county by C. L. Xiang.

FIGURE 2. Type specimens of six Premna taxa. A. holotype of P. yunnanensis (E); B. isotype of P. anthopotamica (A); C. isotype of P. parvilimba (A); D. holotype of P. pilosa (A); E. holotype of P. steppicola (WU); F. isotype of P. subcapitata (K). With the permissions from the Harvard University Herbaria (A), the Herbarium of Royal Botanic Garden Edinburgh (E), the Kew Herbarium (K) and Herbarium of University Vienna (WU).

FIGURE 3. Distribution map of Premna yunnanensis.