﻿Torreyadapanshanica (Taxaceae), a new species of gymnosperm from Zhejiang, East China

﻿Abstract Torreyadapanshanica X.F.Jin, Y.F.Lu & Zi L.Chen, a new species endemic to central Zhejiang, East China, is described and illustrated. This new species is most similar to T.jiulongshanensis (Z.Y.Li, Z.C.Tang & N.Kang) C.C.Pan, J.L.Liu & X.F.Jin, but differs in having leaves with an acuminate apex (vs. leaves with an acute apex), broadly ovoid-globose or globose seeds (vs. obovoid to narrowly obovoid seeds), slightly emarginate at the apex and obtuse-rounded at the base (vs. both acute at the apex and base), testa with irregular shallow grooves (vs. testa smooth or sometimes slightly concave). The diagnostic characters are critically compared and an IUCN assessment for the risk to the new species is estimated.


Introduction
Torreya Arn. (Taxaceae), containing eight species, is distributed in E Asia and SE to W America (Yang et al. 2017). The genus is represented by five species native to China together with Torreya nucifera, a cultivated species. Torreya grandis is both widely distributed and cultivated in East China (Cheng et al. 1978;Fu et al. 1999;Teng et al. 2017).
Female gametophyte tissue of seeds in cultivated Torreya grandis can be produced as edible 'nuts' and are called 'Xiāngfěi' in Chinese, which are available for sale in the markets in Zhejiang Province. In Zhejiang, as Ching reported in Hu (1927), people in Shengxian [Shen Hsien in the Wade-Giles Romanization system of writing Chinese], Kuaiji [Kwei-che], and Zhuji [Chu-che Hsien] have long since been meeting to sell nuts, although the region is very rugged, making traveling and transportation very difficult at that time. The 'Xiāngfěi,' fried seeds of the cultivated varieties viz. T. grandis 'Merrillii', produced from Fengqiao in Zhuji County are the most famous now for their large seeds, high yield, and good quality (Teng et al. 2017).
The species Torreya grandis is widely cultivated in the central to southwestern regions of Zhejiang, and some cultivars had long been recognized (Hu 1927). Chun (1925) described a long-leaved species, T. jackii, which was collected by Ching from Xianju, Zhejiang. Hu (1927) conducted a taxonomic study on Chinese Torreyas, and recognized three native species, placing Torreya fargesii and T. jackii, which have deeply ruminate megagametophyte (female gametophyte tissue) in the sect. Ruminatae, while T. grandis with slightly ruminate megagametophyte was placed in sect. Nuciferae. Based on the variable size and shape of seeds of T. grandis, Hu recognized and described four varieties and one form from Fengqiao, Zhuji County; these infraspecific taxa were later recognized as cultivated varieties of T. grandis (Zhang 1993). Cheng et al. (1975) described Torreya yunnanensis as a new species from NW Yunnan, which was later classified as a variety, T. fargesii var. yunnanensis, by Kang (Kang and Tang 1995). Another new species, Torreya parvifolia described from S Sichuan, is similar to T. yunnanensis but differs in having shorter leaves and smaller seeds (Yi et al. 2006). Kang and Tang (1995) reviewed the taxonomy of the genus Torreya, and described a new variety, T. grandis var. jiulongshanensis, from Suichang County of SW Zhejiang. This variety has longer leaves and deeply ruminate megagametophyte, and was recently treated as an independent species (Teng et al. 2017). Torreya jiulongshanensis is at variance with the broader species concepts of Torreya grandis by Farjon (2010) and Eckenwalder (2009). These authors consider it as a variety or synonym of Torreya grandis.

Torreya dapanshanica
Distribution and habitat. This new species is known only from Mount Dapanshan of Pan'an County, central Zhejiang. It grows at a single location on a forested slope by a stream margin at an elevation of 420-485 m.
Phenology. Pollen cones observed from late early July to early the following April; ovules from mid-November to late the following April. Seeds mature from September to October.
Etymology. The specific epithet 'dapanshanica' refers to the type locality of the new species.  Comparison. Teng et al. (2017) analyzed the leaf variation of all wild species of Torreya from Zhejiang, and found the leaves of T. grandis var. jiulongshanensis were different from those of T. grandis and T. jackii. Consequently, var. jiulongshanensis was treated as an independent species and combined as T. jiulongshanensis. Within some populations identified as T. jiulongshanensis, Teng et al. (2017) mentioned that the leaves from the population in Pan'an were different from the others. Herein, we compared the leaf apex, and found that those from Pan'an (T. dapanshanica) are acuminate, whereas those from Suichang (T. jiulongshanensis) are acute (Fig. 3).
A key to all known species of Torreya from China is shown below. Key to the species of Torreya from China