Carex demissa; The Green Yellow-sedge is quite a rare species on Iceland. The best chance of finding it is in the western coastal regions of Iceland. Typically the inflorescence consist of one male spike (on top) and two or three female spikes closely placed below the male spike. Often though there is a female spike at the middle of the culm too. The leaves of this plant are taller than the infloresence. Also characteristic is the bract under the spikes: this exceeds by far the spikes. This gives it an appearance where the inflorescence is well "within" the plant. Very similar but even more rare is Carex flava (Large Yellow-sedge) It is only found in a few localities in northern Iceland and can be recognized by the long beaks of the utricles.
It is a member of the sedge family (Cyperaceae). It is also known as Carex oederi. The Icelandic name of this species is Grænstör.