(3) 蘇鐵蕨
Brainea insignis (Hook.) J.Sm.
烏毛蕨科（Blechnaceae）

英文名 (English name): Cycad-fern

中國境內現狀: 易危 (VU)。 國家二級保護野生植物。
Status in China: Vulnerable (VU). Wild plant under State protection (category II).

形態特徵：大型蕨類植物。根狀莖粗短，直立，高可達1米，頂端密被棕褐色、具光澤的鑽形鱗片。葉簇生；葉柄長15-30厘米，基部密被鱗片，向上近光滑；不育葉片長約60厘米，寬20厘米，一回羽狀；羽片多數，互生或近對生，線狀披針形，最長者長達12厘米，寬約1厘米，頂端長漸尖，基部心形，邊緣有細密鋸齒；葉脈1-2次分叉，近中脈形成網眼；能育葉與不育葉相似，但較小，長約8厘米，寬約0.4厘米，下部滿佈孢子囊。
　　

地理分布：香港各地。廣東、廣西、台灣、貴州、福建、雲南東南部; 印度至印度尼西亞。
　　

生境與生態：多生長於林下、林緣及山坡草地，有時亦見於次生林中。
　　

本種主幹直立，羽葉婆娑，極似蘇鐵類植物，具有重要的觀賞價值，適合作盆景。在香港以外地區，因生境遭破壞和常被挖掘，現數量日趨減少。本種在香港分布在多個地區，種群並未受任何特別威脅。

Description: Large ferns. Stock stout, forming an erect trunk sometimes up to 1 m tall, apex densely covered with subulate shining brown scales. Leaves tufted; stipes 15-30 cm long, densely scaly at base, glabrous above; sterile lamina about 60 cm long and 20 cm wide, simply pinnate; pinnae numerous, alternate or subopposite, linear-lanceolate, the largest about 12 cm long and 1 cm wide, base cordate, apex acuminate, margin finely toothed; veins close, forking once or twice and forming areoles near the midrib; fertile lamina similar to sterile ones, but somewhat reduced, about 8 cm long and 0.4 cm wide, lower surface almost entirely covered with sporangia.
　　

Distribution: Common in Hong Kong. Guangdong, Guangxi, Yunnan, Guizhou, Fujian, Taiwan; N India to Indonesia.
　　

Habitat and Ecology: On open hillsides, margin of forests and sometimes in secondary forests.
　　

An attractive fern, at first glance it looks like a plant of Cycad and it is very suitable for cultivation as bonsai. Outside Hong Kong, the species is under threats because of destruction of the habitats and over-collection for cultivation as ornamentals. In Hong Kong, it is distributed in various locations and the populations are not under any particular threat.

參考文獻 (References)：
吳兆洪，1990: 中國植物誌4（2）: 197，圖版34。 科學出版社，北京。
Edie, H. H., 1977: Ferns of Hong Kong, 172. Hong Kong Univ. Press, Hong Kong.
So, M.L., 1994: Hong Kong Ferns, 29. The Urban Council, Hong Kong.