Family. Poaceae (Grass family).
Spear grasses are tall (over a metre) or medium-tall (about 40cm). The flowers are clustered into a spray. The florets have two glumes and a single spikelet. The hard lemma encircles the seed, and has a single stout awn rising from the tip of the lemma. The awn is at first almost straight, but on drying, is once or twice bent. Glumes have at least three veins.
Six or more species grow near Castlemaine. The size and character of the ligule, the size of the glumes, lemmas, paleas and awns, the way the awn bends, the hairiness of the leaves, lemmas and awns, the length of the callus, and the shape of the flower cluster (open or contacted) can be important in distinguishing between species. There is much overlap in these characters and identification is not always easy.
Some spear grasses have a cluster of hairs at the tip of the lemma. In native species the hairs are similar in width to those on the lemma. Introduced spear grasses (Nassella) have thicker hairs that are united to form a crown. The crown of Serrated Tussock may be inconspicuous.