Favoritos de cefreebury

On a mossy calcareous boulder. Wrinkled thallus with lobules and spiky extensions at the margin. Single-cell cortex. The thallus is a maze of hyphae and Nostoc chains. Abundant external (or internal?) growth of Gloeocapsa colonies and filaments of "Calothrix/Rivularia" (I forget the species name assigned to species with this morphology in lichens). The latter is spectactularly yellow, both filament and sheath, when mounted in hydroxide. The former are brilliantly purple. The whole is just carnival-coloured. Both Calothrix and Nostoc carry heterocytes, the former basal and the latter intercalary. Both Calothrix and Gloeotrichia were shared with an adjoining black jelly lichen that I have yet to put a name to - the one with those white patches. What a treat all around.