Eleocharis quinqueflora; The Few-flowered Spike-rush is a rather small spike-rush with small (about 6mm) terminal spikes. It is at most 18cm. tall, but usually less so. Like all other Eleocharis species, it grows on wet soils. Differentiating features to other closely related species can be found on the page of Eleocharis palustris (Common Spike-rush).
It is a member of the sedge family (Cyperaceae). The Icelandic name of this species is Fitjaskúfur.