Caustis pentandra, known as the thick twist rush is a widely distributed grass like plant found in many parts of Australia. It may grow to 2 metres tall, often seen in dry open forest, or moist heathland.[1] Stems are a shiny pale green. The specific epithet pentandra is derived from the ancient Greek language, referring to five stamens.[2] This species first appeared in scientific literature in the year 1810, in the Prodromus Florae Novae Hollandiae, authored by the prolific Scottish botanist Robert Brown.