Direct Determination of Arsenic Species in Arsenic Hyperaccumulator Pteris vittata by EXAFS Ultrastructure and subcellular distributions of arsenic and calcium in Pteris vittata L. Effects of harvesting on As accumulation and removal efficiency of As by Chinese brake (Pteris vittata L.) Phosphorus availability in soil-Pteris vittata L. system affected by arsenic New Record of Pteris vittata L. From Jiangsu Province and a Tentative Analysis of Its Dispersal Mechanism Development of Sporoderm and Their Taxonomic Significance in the Fern Pteris vittata L.(Pteridaceae) Effects of arsenic and calcium on metal accumulation and translocation in Pteris vittata L. Study of Vessel Elements in Pteris vittata