Purple Nut Grass

(Cyperos Rotundus) Purple Nut Grass is a perennial sedge growing to 50cm high, with smooth stems triangular in cross section and glossy dark green leaves with small serrations on the margin. The flowers are a cluster of reddish/purplish brown spikelets carried on multiple stems, while seeds are black, brown, olive or grey, oval and ‘beaked’. Purple Nut Grass has an extensive root system of rhizomes, tubers (called ‘nuts’ and which are purplish in colour) and basal bulbs. It spreads mainly from tubers in spring as temperatures rise, with a single tuber often giving rise to hundreds of new plants. It flowers from late spring to summer before the top growth dies back in autumn.