Fairly common on the helipad, which is kept occasionally slashed, giving the smaller forest plants a chance to proliferate. This is the first time I've noticed it in several visits though. The developing nut is tuberculate at the upper end and has 6 plumose hypogynous bristles (photo 6).
achene 1.1 mm long, brown, minutely punctate, ovoid to obovoid, apex with minute apiculum; glumes 2 mm long, veinless or with a very faint lateral vein, midvein dark green, spiklets often marked with red on the lower margins of the glumes, 1 cm to up to 2 cm; caespitose, apparently perennial plant.