Microleana stipoides

Microlaena stipoides is one of the most common native grasses on the eastern seaboard and is well known by native plant enthusiasts of all categories.

It grows in a wide range of habitats, including dry and wet sclerophyll woodlands and forests as well as coastal shrublands and heathlands as well as inland semi-arid habitats. It can dominate some open paddock and grassy areas including road verges. It can also be seen in lawn and turfed situations. It can form dense carpets in some habitats – esepcially after fire and along riparian corridors in inland areas. Microlaena “glades” can sometimes be found on the cumberland plain in western Sydney.

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 agricultural 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 prostrate 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, leaves are to 20 cm long and to 10 mm wide, green to green-blue, and ageing to an orange-brown in summer. Populations of Microlaena have various guises in different places from small plants to larger clumps with more robust leaves.

The stems with the flowering heads in grasses are called culms. In this species, they are to 1 metre tall but often seen smaller.  The flowering period is mostly spring and summer. During this time plants produce very thin and weeping flowering stems above the foliage, with spikelets in a raceme to about 20 cm long. The spikelets consist of two short glumes, then two longer lemmas, which have thin terminal awns of uneven length – a very useful identiification feature.

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 cm long and emerge from the middle of the lemmas. This species is known for embedding itself in the socks of walkers when walking through a dense patch.