Parramatta Grass

The hairless (i.e. glabrous) flowering stems (i.e. culms) are slender (1.5-3 mm thick), but somewhat wiry, and are usually not branched. The alternately arranged leaves are very thin (i.e. linear) and consist of a leaf sheath, which partially encloses the stem, and a spreading leaf blade. The leaf sheaths (4-12 cm long) are slightly hairy (i.e. sparsely pilose) or hairless (i.e. glabrous) and the lower ones become somewhat papery with age. The leaf blades (6-40 cm long and 1-5 mm wide) may be either flat or somewhat rolled (i.e. weakly convolute). They are hairless (i.e. glabrous) and have pointed tips (i.e. acuminate apices). Where the leaf sheath meets the leaf blade there is a fringe of tiny hairs (i.e. ciliated ligule) or a tiny membrane (0.1-0.3 mm long) topped with hairs (i.e. ciliated membrane).

The dark green, dark grey or greyish-green coloured seed-heads, which are borne at the top of the flowering stems (i.e. culms), are very thin and elongated in appearance (6-35 cm long and 3-8 mm wide). They are upright (i.e. erect), spike-like (i.e. spiciform panicles), and have many short branches (10-20 mm long) that are held very closely (i.e. appressed) to the main stem of the seed-head. These branches are quite densely arranged along the stem and are only sometimes interrupted near the base of the seed-head. Each of these seed-head branches bears numerous tiny, densely packed, flower spikelets almost to its base. The elongated (i.e. lanceolate) or egg-shaped (i.e. ovate) flower spikelets (2-2.8 mm long and 0.6-0.8 mm wide) contain a single tiny flower (i.e. floret) inside two bracts (i.e. glumes). The lower bract (i.e. glume) is 0.4-0.7 mm long and the upper bract (i.e. glume) is 1-1.5 mm long (i.e. at least half the length of the flower spikelet). Flowering occurs throughout the year, but is most abundant from spring through to late autumn (i.e. from October to June). The oblong, oval-shaped (i.e. ellipsoid), or almost rounded (i.e. sub-globular) 'seeds' (i.e. grains or caryopses) turn dark red or reddish-brown in colour as they mature. They are tiny (1.1-1.5 mm long and up to 0.6 mm wide) and separate from the remainder of the flower spikelet at maturity (i.e. the whitish-coloured old glumes remain on the seed-head).

This species produces large quantities of tiny seeds.These seeds are sticky when wet and readily become attached to animals, clothing and vehicles. They may also be dispersed by water, in mud, and in contaminated agricultural produce (e.g. in fodder and pasture seed lots).