Eragrostis setifolia

The grass belongs to Eragrostis, the most species rich genus within the subfamily Chloridoideae.[4] The genus was first described by Nathanael Matthaeus von Wolf in 1776 and currently has approximately 350 species.[4] Eragrostis setifolia was classified as a species by Nees in 1843.[5]

Eragrostis setifolia is an erect perennial tussock forming grass.[6] It may reach a height of 60 cm (24 in), however it is most commonly between 10–50 cm tall.[2][6] The species has a poorly developed rhizome and produces a compact tussock.[2] The morphology of the cataphylls can vary from hairless to bearing hair like projections.[6] Cataphylls are often either shiny or leathery and may be oval shaped or tapered.[6] The leaves are generally rough and glabrous.[6] The culms are wrapped in broad sheaths.[6] Leaves are generally about 4–13 cm in length, rolled and taper to point.[6] The flowers of this grass are dense and pointed.[2] They are approximately 3–12 cm in length and reach a width of 1.5–3 cm.[2] The flowers range from pale to light purple in colour and are attached via short branches up to 3 cm in length.[2] The grass produces 10-50 spikelets with a pale to slightly purple shade.[2] Spikelets reach approximately 2 cm in length and 1.5 cm in width.[2] Seeds are small only reaching 0.08 mg in mass.[7]

Eragrostis setifolia is an Australian native common throughout the semi-arid interior of Australia.[3] It is found in all mainland Australian states with the highest density in western New South Wales, South Australia and the Northern Territory.[3] It tends to be most commonly associated with semi-arid woodlands and shrub-lands including Coolibah and black box woodlands and salt bush communities.[2][6] This grass is also a common component of native grasslands including Mitchell grasslands.[8] Eragrostis setifolia is most abundant in relatively moist refuges within its habitat range.[9] It tends to be associated with low lying areas.[10] The most favourable habitat for Eragrostis setifolia is land that is subject to periodic inundation such as gilgais and floodplains.[10] This grass is most abundant in clay dominated soils ranging from red, brown, grey or black clay.[6] The affinity to clay soils is due to the high water holding capacity of these soils.[9] It is less common in sandy areas however it may also inhabit sandy/loam environments that are subject to flooding (e.g. near flood plains or water courses).[6] It is occasionally found on found in saline or calcareous soils.[6] Eragrostis setifolia is tolerant or even favoured by infertile soils.[11]

Eragrostis setifolia is a summer growing (C4) grass.[1] It is capable of year round flowering and seed set.[2] It tends to respond positively to rainfall events with growth, germination and flowering coinciding with rainfall and water availability.[12] Germination is highly dependent on rainfall and is severely depauparate in the absence of moisture.[12][7] It is quite drought tolerant and tends to die back during severe water shortages only to re-sprout again in periods of rain.[2] The grass also appears to readily colonise burnt areas such as burnt spinifex grasslands.[13]

It is commonly grazed by native herbivores such as macro pods, the red kangaroo in particular preferably grazes it.[14] Its main use for humans is its value for livestock grazing.[2] Eragrostis setifolia is relatively resilient and productive and thus it is often considered a useful fodder plant.[6] It is tolerant to grazing when compared to other native grasses (such as Mitchell grass) and can withstand grazing pressure that would lead to the elimination of other native grasses.[15] In addition to being consumed by native wildlife it provides important habitat for native species such as the plains rat (Pseudomys australis).