Fig. 1. SEM photo of sporangia

Fig. 2. Illustration of the scanned area

Fig. 3. Arsenic distribution in sporangium of P. vittata

Fig. 4. Micro-speciation of As in sporangium, spores and pinnae of P. vittata

Fig. 5. Elements distribution in sporangium of P. vittata
(a): K distribution; (b): Ca distribution; (c): Fe distribution; (d): S distribution; (e): Cu distribution; (f): Zn distribution