Five new synonyms in Epimedium (Berberidaceae) from China

Abstract Five new synonyms in Chinese Epimedium are designated in the present paper. Epimedium chlorandrum is treated as a synonym of Epimedium acuminatum; Epimedium rhizomatosum as a synonym of Epimedium membranaceum; Epimedium brachyrrhizum as a synonym of Epimedium leptorrhizum; Epimedium dewuense as a synonym of Epimedium dolichostemon; and Epimedium sagittatum var. oblongifoliolatum as a synonym of Epimedium borealiguizhouense.

Distribution and habitat. Epimedium acuminatum is widely distributed in Sichuan, Chongqing, Guizhou, and northern Yunnan. It usually occurs in forests, thickets, bamboo forests, and weedy slopes ranging from 270 to 2400 m in elevation.
Phenology. Epimedium acuminatum fl owers from April to May, and fruits from May to June.
IUCN Red List category. Although Epimedium acuminatum has a relatively wide distribution in China; it should be designated as Vulnerable (VU) (IUCN 2013), because of exploitation for medicinal use, especially in Guizhou.
Notes. Epimedium acuminatum is one of the most widespread species in the genus, and exhibits much variation in morphology; therefore, it is not surprising that there are several synonyms associated with it. Léveillé (1909) published Epimedium komarovii H. Lév. upon only contrasting it with E. sagittatum Maxim., Stearn (1938) found that it was not distinct from E. acuminatum and reduced it into synonymy. Epimedium simplicifolium T.S. Ying was described by Ying (1975), only separating it from E. acuminatum in having unifoliolate, sericeous leaves. Upon extensive specimen examination, however, Zhang et al. (2011) found that the diagnostic characters of E. simplicifolium were within the range of morphological variations of E. acuminatum and placed E. simplicifolium into synonymy.
Epimedium chlorandrum was described by Stearn (1997) as having the inner sepals being slightly ascending, and not closely appressed to the petals, and the anthers and pollen as being green. However, observations from the type locality of E. chlorandrum show that the diagnostic character of the inner sepals as not closely appressed to the petals is not stable, and E. acuminatum is also found having inner sepals being slightly ascending, with green anthers and pollen. Th ere is no diff erence in morphology for the two species, thus, E. chlorandrum is here treated as a new synonym of E. acuminatum. Additionally, extensive specimen examination and fi eld investigation demonstrate that it is incorrect for Stearn (1997) to recognize the color of anther and pollen as diagnostic features in Epimedium because, besides E. acuminatum, other Epimedium species (e.g. E. sagittatum, E. sutchuenense Franch., E. elongatum Kom., and E. leptorrhizum Stearn) with yellow anthers and pollen are also found with green anthers and pollen.  Phenology. Epimedium membranaceum fl owers from April to June, and fruits from May to July.
IUCN Red List category. Epimedium membranaceum should be designated as Least concern (LC) according to IUCN Red List criteria (IUCN 2013).
Notes. Ying (1975) placed Epimedium membranaceum into synonymy of E. davidii Franch., which was adopted by the Flora Reipublicae Popularis Sinicae (Ying 2001) and the Flora of China (Ying et al. 2011). However, the two species can be easily distinguished by petal shape, with the petals of E. davidii bearing obvious lamina while those of E. membranaceum have no lamina. Additionally, Epimedium davidii was treated as the type species of series Davidianae Stearn while E. membranaceum was referred to series Dolichocerae Stearn in the updated taxonomic system of Epimedium (Stearn 2002).
Epimedium rhizomatosum is much like E. membranaceum. In the protologue for E. rhizomatosum, Stearn (1998) distinguished it from E. membranaceum in rhizome shape, closeness of spines along the leafl et margin, infl orescence morphology, and number of fl owers. Epimedium membranaceum had a compact rhizome with annualgrowth shoots 1-2 cm long while E. rhizomatosum had an elongated rhizome and annual-growth shoots about 3-5 cm long; the leafl ets of E. membranaceum had about 9-11 spines to 3 cm of leafl et margin whereas leafl ets of the same size in E. rhizomatosum had about 15-17 spines to 3 cm of margin; E. membranaceum had a 30-40 cm long infl orescence with numerous well-separated fl owers whereas E. rhizomatosum had a much shorter infl orescence with fewer, more crowded fl owers. However, based on extensive investigation in herbaria and the fi eld, it was found that E. membranaceum continuously varies in the morphology of these organs and the diagnostic features of E. rhizomatosum can fall into the variation range of E. membranaceum. For instance, E. membranaceum not only has compact but also slender and elongated rhizome in the type locality (even in one collection X.J. He et al. 131825 (SZ)).Th erefore, E. rhizomatosum is here reduced as a new synonym of E. membranaceum.

Epimedium dolichostemon Stearn
Epimedium Notes. He and Xu (2003) recognized E. dewuense as a new species based only on the comparison with E. sagittatum but not with E. dolichostemon. According to the protologue of E. dolichostemon and E. dewuense, the two species can be distinguished by the shape and indumentum of leafl ets: E. dolichostemon bears narrowly ovate leaves glabrous on both sides, while E. dewuense has wider leaves pubescent on both sides (Stearn 1990;He and Xu 2003). Based on investigations in herbaria and the fi eld,