蛇足石杉

Huperzia serrata (Thunb. ex Murray) Trev. in Atti Soc. Ital. Sci. Nat. 17: 247. 1874; Rothm. in Fedde, Repert. Sp. Nov. 54: 58. 1944; Sen et Sen in Fern Gaz, 11 (6): 417. 1978: Ching in Acta Bot. Yunnan. 3 (3): 294. 1981; C. Y. Yang in ActaPhytotax. Sinica 20 (4): 447. 1982; Ching et S. K. Wu in C. Y. Wu, Fl. Xizang. 1: 11. 1983: P. S. Wang et X. Y. Wang in Guizhou Sci, 2: 49. 1983; Fl. Anhui, 1: 18, f. 1, 1985; H. S. Kung, Fl. Sichuan. 6: 30, Pl. 3: 1-7. 1988; Fl. Liaoning. 1: 10, Pl. 1: 6-7. 1988: Bir et al. in Ind. Fern J. 6: 33. 1989: B. Ollg. in Opera Bot. 92: 164. 1987, et Index Lycop. 20. 1989; J. Z. Wang in Journ. Hebei Forest. coil. 5 (2): 115. 1990; S. F. Wu in Shanghai Teach. Loll. Tech. 10 (4): 89. 1990; Nakaike, N. Fl. Jap. Pterid. rev. enlarg. 792. 1992; P. S. Wang, Pterid. Fanjing Mt. 18. 1992: Fl. Jiangxi 1: 24, f. 8. 1993; Fl. Zhejiang 1: 2, f. 1-1. 1993; X. Y. Wang inBull. Bot. Res. 14 (4): 356. 1994; Keys Vasc. Pl. Wuling Mts. 4. 1995; L. B. Zhanget H. S. Kung in Acta Phytotax. Sin. 38 (1): 14. 2000. ——Lycopodium serratumThunb. ex Murray, Sys. Veg. ed. 14. 1784 (May-Jul. ) ; B. Ollg. l. c. 70. ——L. ser-ratum Thunb. Fl. Jap. 341, t. 38. 1784 (Aug. ) ; C. B. Clarke in Trans. Linn. Soc. II. Bot. 1: 591. 1880: Baker, Handb. Fern Allies 30. 1887; Christ in Bull. Acad. Geogr. Bot. 11: 271. 1902; Hayata, Ic. Pl. Formos. 4: 133. 1914; Alderw, Malay. Fern-allies30. 1915; Iljin in Kom. , Fl. URSS. 1: 114. 1934; Alston in Fl. Indo-Chine 7 (2): 548. 1951; S. H. Fu, Ill. Imporant Chinese Pl., Pterid. 2. f. 1. 1957; Herb. Pl. Northeast China 1: 2, f. 1. 1958: Tagawa, Col. Ill. Jap. Pterid. 9. Pl. 1-5-a. 1959; Fl. Hainan. 1: 8. 1964: Mehra et Bir in Res. Bull. Panjab Univ. 15 (1-2): 101. 1964; Tagawa in Hara, Fl. E. Himal. 2: 199. 1971; Ic. Corm. Sin. 1: 107. f. 214. 1972; Fl. Tsinling. 2: 15. 1974; Y. L. Chang et al, Sporae Pterid. Sin. 39. Pl. 1: 26-29. 1976: Fl. Jiangsu 1: 11, f. 2. 1977; Tagawa et K. Iwats. in Fl. Thailand3 (1): 7. 1979; Fl. Henan 1: 2, f. 1. 1981: Fl. Fukien 1: 8, f. 5. 1982; Nakaike, N. Fl. Jap. Pterid. 30. f. 30. 1982; C. M. Kuo in Taiwania 30: 11. 1985; Fl. Fuj ian. rev. 1: 8, f. 5. 1991; K. Iwats. , Ferns Fern Allies Jap. 43. 1992; J. L. Tsai et W. C.Shieh in T. C. Huang, Fl. Taiwan ed. 2, 1: 42. 1994.——Urostachys serratus (Thunb. ex Murray) Herter ex Nessel, Baerlappg. 56. 1939. ——L. javanicum Sw. Syn. Fil. 175, 399. 1850. ——L. serratum Thunb. ex Murray var. thunbergii Makino in Bot. Mag. Tokyo 12: 12. 1898. ——L. serratum Thunb. ex Murray var. jazxanicum (Sw.) Makino in Bot. Mag. Tokyo 12: 13. 1898. p. p. : Takeo，Ill. Formos. Pl. Suppl. 7. f.7. 1928. ——L. serratum Thunb. ex Murray var. longipetiolatum Spring，Monogr. Ly-cop. 2: 18. f. 1: 9-11. 1850; Tagawa，l. c. 10. pl. 1-5-b. f. 2: 5; De Vol in H.L. Li，Fl. Taiwan 1: 29. 1975; K. Iwats. ，l. c. 43. ——H. serrata (Thunb. ex Murray) Trev. f. longipetiolata (Spring) Ching in Acta Bot. Yunnan. 3 (3): 294. 1981;Fl. Dulongjiang Reg. 1. 1993; Fl. Jiangxi 1: 25. 1993. ——L. serratum Thunb. exMurray var. myriophyllifolium Hayata，Ic. Pl. Forms. 4: 133. 1914: De Vol，1. c. 30; J. L. Tsai et W. C. Shieh，1. c. 42. ——Urostachs myriphyllifolius (Hayata) Hert-er, Index Lycop. 71. 1949 (“myriophyllus”). ——H. myriophyllifolia (Hayata) Holubin Folia Geobot. Phytotax. 20: 75. 1985. ——L. serratum Thunb. ex Murray var. inter-medium Nakai in Bot. Mag. Tokyo 39: 285. 1925; Tagawa，l. c. f. 3-4; K. lwats. ，l. c. 43. 1992. ——H. serrata (Thunb. ex Murray) Trev. f. intermedia (Nakai) Ching，l. c. 294. ——H. serrata (Thunb. ex Murray) Trev. f. intermedia (Nakai) Ching et S.K. WuinC. Y. Wu，Fl. Xizang. 1: 11. 1983. ——H. serrata (Thunb. ex Murray) Rothm. ，l. c. 59. ——H. selago (L.) Bernh. ex Schrank et Mart. var. serrata (Thunb.ex Murray) Love et Love in Univ. Color. Stud. 17: 5. 1965.

多年生土生植物。茎直立或斜生，高10-30厘米，中部直径1.5-3. 5毫米，枝连叶宽1.5-4.0厘米，2-4回二叉分枝，枝上部常有芽胞。叶螺旋状排列，疏生，平伸，狭椭圆形，向基部明显变狭，通直，长1-3厘米，宽1-8毫米，基部楔形，下延有柄，先端急尖或渐尖，边缘平直不皱曲，有粗大或略小而不整齐的尖齿，两面光滑，有光泽，中脉突出明显，薄革质。孢子叶与不育叶同形；孢子囊生于孢子叶的叶腋，两端露出，肾形，黄色。

全国除西北地区部分省区、华北地区外均有分布。生于海拔300-2700米的林下、灌丛下、路旁。亚洲其他国家 (如日本、朝鲜半岛、泰国、越南、老挝、柬埔寨、印度、尼泊尔、缅甸、斯里兰卡、菲律宾、马来西亚、印度尼西亚等) 、太平洋地区、俄罗斯、大洋洲、中美洲有分布。模式标本采自日本，存于瑞典。

许多蕨类学者在本种下又分数个变种或变型，我们认为，对于这样的广布种，宜采用相对大一点的种的概念，因而本文将有关种下等级予以归并。

叶缘具粗齿是本种的识别特征。