5. Osmunda vachellii Hooker, Icon. Pl. 1: t. 15. 1836.
华南紫萁 hua nan zi qi
Rhizome erect, stout, woody. Fronds simple pinnate, with numerous rather distant pinnae, up to 1 m × 20-30 cm; pinnae 15-20 pairs, subopposite, ascending, ca. 2 cm apart; sterile pinnae linear-lanceolate, up to ca. 20 × 1-17 cm, base narrowly cuneate, shortly stalked, articulate to rachis, margin entire or slightly undulate, apex acuminate; veins free, 1 or 2 times branched; basal pinnae fertile, reduced to midrib with small lobes bearing sporangia, rarely with a few reduced sterile pinnae below fertile ones.
Hillsides, often by streams, sometimes in open sites, locally common; 100-1000 m. Chongqing, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hunan, Jiangxi, Sichuan, Yunnan, Zhejiang [India, Myanmar, Thailand, Vietnam].
Osmunda vachellii is very attractive and appears like a Cycas. It can be confused with O. javanica, a similar fern common in countries further south. The latter has rather wider pinnae, up to 2-3 cm, with the base more broadly cuneate to rounded; also, the fertile pinnae are commonly near the middle of the fronds.