Botrichium lunaria; The Common Moonwort is a tiny fern species. Usually it's size does not exceed 5cm. Under specific circumstances it can be taller: I have seen plants of this species in the undergrowths of birch scrub at Skaftafell which were at least 20 cm tall. However, under most circumstances this is a tiny plant. The Icelandic name for this species is Tungljurt. Moonworts are quite strange plants: they form only two small leaves during the growing season: one leaf only serves vegetative functions - thus resembling a normal leaf. The second leaf contains only spore-forming organs with characteristic globular structures.
The Common Moonwort can be found all over Iceland. However there are also 2 closely related species being the Northern Moonwort (Botrychium vulgare) and the Lance-leaved Moonwort (Botrychium lanceolatum). Both are rare.