English: A lichen - Ochrolechia androgyna This lichen was growing on one of a number of rocks that were heaped up in a disused quarry. This specimen is damp, and the colours therefore appear a little different from those of the same species when dry. Lichens are made up of both fungal and algal cells. The paler margin, called the prothallus, lacks algal cells. In this photo, the lichen does not have any spore-producing discs (though this species does sometimes have them); instead, some small greenish powdery-looking areas can be seen, particularly concentrated towards the centre of the photo. These areas are called soralia, and they contain loose packages of algal and fungal cells called soredia; these, when dispersed, can develop into new lichens. This species therefore mainly reproduces asexually (by means of soredia), rather than sexually (by spores).