Bot. Bull. Acad. Sin. (2005) 46: 363-366

YANG — New species, Ephedra

A new species of Ephedra L. (Ephedraceae) from Sichuan, China with a note on its systematic significance

Yong YANG*

Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, P.R. China

(Received June 4, 2004; Accepted April 1, 2005)

Abstract. A new species, Ephedra dawuensis Y. Yang, is described and illustrated. This species is similar to E. equisetina Bunge in having thin branchlets 0.8-1 mm in diam. and brown scale-like leaves, and to E. saxatilis Royle ex Florin in having oblong-ellipsoid seeds and a short micropylar tube ca. 0.5 mm long. It differs from E. equisetina in having female cones bearing 2 or 3 pairs of bracts (vs. 4 or 3 pairs of bracts), purplish black, oblong-ellipsoid seeds (vs. ovoid seeds), and a shorter micropylar tube (vs. 1.5-2 mm long), and from E. saxatilis in having thinner branchlets and brown scale-like leaves (vs. yellowish, narrow triangular, leaves). This new species is assigned to E. sect. Ephedra in that the bracts of female cones become fleshy at maturity. Intermediate character states of this new species provide evidence for the hypothesized affinity between E. equisetina and E. saxatilis.

Keywords: China; Ephedra dawuensis; Ephedraceae; Himalayas; Taxonomy.

Introduction

In 1999, I noticed a new form of Ephedra from Sichuan of China (W.K. Hu 13049) that I realized was a new species because of the unique combination of E. equisetina Bunge-like vegetative characters and E. saxatilis Royle ex Florin-like reproductive characters. I had only one specimen at my disposal at that time and needed more specimens to confirm my viewpoint. Fortunately, in the summer of 2002, Dr. M. Mikage of the Faculty of Pharmaceutical Sciences, Kanazawa University and his colleagues collected some specimens of Ephedra from Sichuan of China including one specimen (M. Mikage, A. Takahashi, T. Okutsu, Q. S. Li 0101075) identical to W. K. Hu 13049. This corroborated my former assumption that this entity is a new species. Further investigation on testa sculptures of over 40 Ephedra species (Yang, unpubl. res.) indicated that the testa sculpture of this new species (Figure 2A) differs from that of E. saxatilis (Figure 2C) in having a clear cellular profile and an impressed intercellular furrow, and from that of E. equisetina (Figure 2B) by the absence of a warty testa sculpture.

Ephedra dawuensis Y. Yang, sp. nova—TYPE: China. Sichuan, Garzę Xian (31°36' N, 99°54' E), on slopes, woody, ca. 0.5 m tall, fruit red, common, 7 Sep 1951, W. K. Hu 13049 (holotype, PE). (Figure 1)

Haec species nova affinis Ephedrae saxatili Royle ex Florin et E. equisetinae Bunge, a illa differt ramulis gracilioribus, foliis brunneis squamiformibus, a hac differt seminibus oblongis ellipsoideis.

Diagnosis. This new species is similar to E. saxatilis and E. equisetina, but differs from the former by its thinner green branchlets and brown scale-like leaves, and from the latter by the female cones bearing 2 or 3 pairs of bracts, the purplish black, and oblong-ellipsoid seeds, and a shorter micropylar tube.

Description. Plants woody, to 0.5 m tall. Stems woody, to 21.6 cm × 6 mm on specimen; bark grayish black, smooth to rough, longitudinally split. Branchlets densely clustered at nodes of woody stems, yellowish green, 3-9 cm long; internodes 1.7-3 cm long, 0.8-1 mm in diam., densely and finely warty. Leaves 2 at nodes, brown and scale-like, triangular, 2-4 mm long, basal 1/2 fused to completely split, apex slightly recurved, acute to obtuse. Male cones unknown. Female cones paired or solitary at nodes, pedunculate; peduncles ca. 4 mm long. Bracts in 2 or 3 pairs, fused for ca. 2/3 their length, fleshy at maturity. Seeds 1 or 2 in each cone, included in bracts, purplish black, oblong-ellipsoid, 6.1-6.8 × 3.1-3.4 mm, apex acute when ventral surface plane and dorsal surface convex, or apex slightly beaked when both ventral and dorsal convex. Micropylar tube straight, short, ca. 0.5 mm long.

Etymology. The specific epithet is derived from the county name of the type locality, Dawu Xian, Sichuan Province, China.

Relationships. Ephedra dawuensis Y. Yang clearly belongs to E. sect. Ephedra because it has red, fleshy bracts when the mature female cones are mature. This species is similar to E. saxatilis in the strong, erect, woody stems, and the reproductive characters, e.g., the purplish black seed color, the oblong-ellipsoid seed shape, the short micropylar tube (ca. 0.5 mm long), the bracts in 2 or 3 pairs, and the degree of fusion of uppermost pair of bracts of

*Corresponding author. E-mail: ephedra@ibcas.ac.cn; Tel: 86-10-62836115 (O); Fax: 86-10-62590843.


Botanical Bulletin of Academia Sinica, Vol. 46, 2005

Figure 1. Ephedra dawuensis Y. Yang (from holotype, drawn by Ying-bao Sun). A, Habit. Bar: 1 cm; B, Female cone. Bar: 3 mm; C, Seed, dorsal view. Bar: 3 mm; D-E, Variation of seed shape; D, Seed, ventrally plane, lateral view. Bar: 3 mm; E, Seed, ventrally convex, lateral view. Bar: 3 mm.


YANG — New species, Ephedra

the female cones (Table 1). Ephedra dawuensis is also similar to E. equisetina in the thin branchlets (ca. 0.8-1 mm in diam.), the brown scale-like leaves, the woody habit, the seeds sometimes beaked and ventrally swollen (Figure 1E; Table 1). This assemblage of characters suggests that the new species is closely related to both E. saxatilis and E. equisetina and that the three species may form a clade.

Pachomova (1971) assumed that E. saxatilis is closely related to E. equisetina based on a study of female cone characters of the genus. Mussayev (1978) further considered that E. saxatilis may be derived from E. equisetina. However, no immediate characters have been reported. The present author believes that the two species are closely related because of their shared overall similarity in the frequent uniovulate cones bearing large seeds, fewer pairs of bracts, and the strong, woody habit. The discovery of E. dawuensis provides further evidence for the close relationship between E. saxatilis and E. equisetina because E. dawuensis has some intermediate characters between the two species (Table 1).

Ephedra dawuensis differs from E. equisetina in having female cones bearing 2 or 3 pairs of bracts, purplish black, oblong-ellipsoid seeds, and a shorter micropylar tube, and from E. saxatilis in having thinner branchlets and brown scale-like leaves. Seed surface sculptural characters are important to systematics of Ephedra (Yang, unpubl. res.), those of E. dawuensis, E. equisetina, and E. saxatilis, were studied by using SEM (Figure 2A-2C). The results indicate that the three species have clearly distinguishable seed surface sculptural characters. Ephedra equisetina has warty seed surface ornamentations (Figure 2B) that are fundamentally different from the smooth pattern of E. dawuensis with clear profile of epidermal cells (Figure 2A) and the irregular seed surface of E. saxatilis (Figure 2C). In short, E. dawuensis shows close affinity with E. saxatilis in its reproductive organs but with E. equisetina in its vegetative organs. In addition, both E. dawuensis and E. saxatilis are endemic to Himalayas while E. equisetina is widespread through Mid-Asia, from the Canary Islands eastward to Shandong of

Figure 2. Seed sculpture of three Ephedra species. A, Ephedra dawuensis showing the impressed intercellular furrows. Bar: 50 µm; B, Ephedra equisetina showing warty sculpture. Bar: 100 µm; C, Ephedra saxatilis showing irregular seed ornamentation. Bar: 50 µm.


Botanical Bulletin of Academia Sinica, Vol. 46, 2005

China. This combination of evidence suggests that E. dawuensis and E. saxatilis might be derived from a common ancestor close to E. equisetina with the Himalayan uplift.

In conclusion, E. dawuensis and E. saxatilis are closely related to each other. They may share a common ancestor with E. equisetina. Further studies are encouraged to illuminate the relationships among these species in detail.

Additional specimens examined. China, Sichuan, Garzę Zangzu Zizhouzhou, Dawu Xian, Xianshui Town (30°59.261' N, 101°07.215' E), alt. 3,100 m, 30 Jul 2001 (fr.), M. Mikage, A. Takahashi, T. Okutsu, Q. S. Li 0101075 (paratype, PE).

Acknowledgements. The author is grateful to Mr. Ying-bao Sun for his illustration and to Ms. Qin Ban of PE for her kind help in arranging specimens. Thanks are also given to Dr. M. Mikage of Kanazawa University for his specimens from Sichuan,

China, to Prof. Dr. S. S. Renner of München University, and to N. Turland of MO for their valuable suggestions on the manuscript. This work was supported by National Natural Science Foundation of China (Grant no. 30370105) and a project from the Chinese Academy of Sciences (Grant no. Ksxc2-sw-108).

Literature Cited

Mussayev, I.F. 1978. On geography and phylogeny of some representatives of the genus Ephedra L. Bot. Zhurn. 63: 523-543.

Pachomova, M.G. 1971. Ephedraceae. In V.I. Glubov, M.G. Matzenko, and M.G. Pachomova (eds.), Plantae Asiae Centralis, Vol. 6. Academia Scientiarum URSS Institutum Botanicum nomine V. L. Komarovii, Leningrad, pp. 25-33.

Yang Y. Patterns of seed surface sculptures of Ephedra (Ephedraceae). Unpubl. res.