Common polypody contains a substance 500 times sweeter than sugar! It has been used for its taste qualities in sweets such as nougat. The plant also has many medicinal qualities. Since ancient times, it hab been used as a laxative and a remedy for coughs, hepatitis, etc. The new sori, which hold the spores, are on the underside of fresh fronds (leaves). When unripe, you can barely see them since they are practically the same color as the frond. But once they start to ripen, they are the most characteristic part of the plant.