Genetic structure and phylogeography of a relict tree fern, Sphaeropteris brunoniana (Cyatheaceae) from China and Laos inferred from cpDNA sequence variations: Implications for conservation Spore Propagation and Rejuvenation of Sphaeropteris lepifera Sphaeropteris, a newly recorded genus of tree ferns from Guangxi Gametophyte Morphological Variations of Sphaeropteris brunoniana(Cyatheaceae) under Four Culture Conditions Spore Propagation and Rejuvenation of Sphaeropteris lepifera Gametophyte Development of Three Species in Cyatheaceae