The common polypody (Polypodium vulgare) is a medium-sized fern found in damp, shady gorges and banks in woodlands, as well as rocks, walls and on mossy branches. The fronds are made up of simple, finger-like leaflets either side of the main stem and offset by half the width of each leaflet. The spore-bearing organs, sori, are small and round, and are found on the underside of the fronds; they range in colour from bright yellow to orange. On the upper side, the positions of the sorus (spores) are marked by pale raised blisters. It remains green throughout the year. Photographed in Reykjavik Botanic Garden, Iceland. |