Poa labillardierei

A tussock grass, forming clumps to about 50 cm or more across, with flowering heads up to 1.2 metres tall.

It is a widespread species in NSW, growing mostly on the coast and tablelands subdivisions, but also found further west on the central western slopes and western plains. It extends into Queensland, (mostly the south-east) but in disjunct populations towards central Queensland and further north to Cairns. It is widespread in Victoria as well as the east of South Australia.

It is often found in moister vegetation, especially enriched wet sclerophyll forests and rainforest edges. It is also found on creeklines, usually on enriched soils.

The family Poaceae is the grass family (any species outside this family should not be referred to as grasses). They are a group that a lot of us place in the “too-hard” basket but here are some simple facts about them: They are one of the largest groups of flowering plants, in the large monocotyledonous group (sedges, lillies, palms and orchids amongst others), with highly modified flowers and reduced perianth parts. Pollen from the anthers is generally wind-blown and is received by the female pistils. It is thought that grasses have evolved to dominate the planet over the last several 100,000 years, due to a general drying and cooling of many terrestrial areas. Hence, we have the grass-prairies of America, Africa and Australia, as well as other areas with a general reduction in vegetation like rainforests.

It is worth remembering that humanity relies heavily on the seeds of 3 grass species for food; namely Wheat (Triticum aestivum), Corn (Zea mays) and Rice (Oriza sativa) – not to mention fodder for agrciultural meat.

Identification of grasses can be difficult if one is to plunge ‘in-depth’ but many genera can be identified by the appearance of their inflorescences. Different terminology is applied. Petals and sepals do not apply to flowers but rather structures such as glumes which are bracts that generally support the base of ‘spikelets’ (clusters of flowers or single flowers) with flowers generally called “florets”. Florets typically consist of a palea and a lemma (two joined structures which house the stamens and carpels). Florets can be bisexual or unisexual or sterile. In some genera, glumes are absent. Inflorescence structures are generally familiar, i.e. panicles, racemes, spikes etc).

There are a range of habits such as tussocks or clumping grasses (Poa, Themeda, Cymbopogon etc), to large clumping and running bamboos (world’s largest grasses) and stoloniferous grasses – those that creep prostrately over the ground using stolons (eg: turf grasses such as Kikuyu (*Cenchrus clandestinus) and Oplismenus aemulus).

Grasses produce simple leaves, usually made up of a blade and sheath with accompanying parts such as auricles, ligule and collars (where the blade joins the sheath). In this species, they are heavily clustered at the base, to 80 cm long and to 0.4 cm wide, mid to dark green in colour, soft to the touch.

The stems of the flowering heads in grasses are called culms. In this species, they are to 1 metre tall with terminal spikelets produced in an open panicle to 25 cm long by about 10 cm wide. Spikelets are generally very small with an overall bluey-green-grey colour, aging to brown. Florets are shortly hairy and often have a pinkish tinge. Flowers most of the year.

Grasses mainly produce a grain or caryopsis (there are some cases of berries, nuts and utricles). A grain is a fruit which is basically ‘all seed’ with very little associated tissue and can therefore germinate rapidly. In this species, they are about 1 to 2 mm long with an oval to cylindrical shape.