Cope & Gray (2009) refer to Nardeae as “an odd little tribe whose unusual spikelets give no clue as to its origin or affinities”.
There is only 1 genus (Nardus) and only one species (Nardus stricta) in Europe.
Nardus stricta (Mat Grass)
A densely tufted perennial with very short rhizomes which means it grows in dense mats (hence the common name). The leaves narrow and very tough and wiry (unpalatable to livestock) and squarrose (leaves held perpendicular to the sheath). The ligule is about 0.5 mm on the basal leaves but longer, 1-2 mm, on the culm leaves. The narrow leaves can suggest Festuca ovina but the ligules of Festuca are minute so even the short ligule of Nardus basal leaves will tell you its Nardus.
The inflorescence is a spike-like raceme bearing 1-flowered spikelets which are dorsally compressed and borne edgeways on the axis. The glumes are reduced (so much so you will struggle to find them!) and the lemmas 3-nerved tapering into an awn. The inflorescence takes on a bleached white, fish-bone appearance in autumn. Nardus is widespread in Britain often on peaty soils in acid habitats upland and lowland such as heathland and acid grassland.
Next tribe is the Arundineae, watch out, interesting ligule this way comes!