Isolepis prolifera has a caespitose (tufted) growth form, with round stems up to tall and wide. Its leaves are reduced to red or brown sheaths around the stem, sometimes with a small free lobe up to long. Its flowers are arranged in a cluster of
spikelets, long and wide. Many of the spikelets are, however, replaced by branchlets, each long, and terminating in a further head of spikelets. This proliferation into branches gives the species its scientific name ''''. Each spikelet consists of up to 30 flowers, and the fruit is a nutlet with fine reticulations on its surface.
Isolepis prolifera varies considerably in size, and smaller specimens may resemble the Australasian species
Isolepis inundata, although
I. inundata normally has some true leaves, and is not always proliferating. ==Distribution==