Restio sieberi, commonly known as common Capereed and in Afrikaans as besemriet (broom reed), is a straggly, tufted perennial, a rush-like plant reaching heights from 60 cm to 1 m.
This variable plant belongs to the subfamily Ischyrolepis. One of the earlier names of the species was Ischyrolepis sieberi.
The cylindrical culms or stems are straight and warty (or puncticulate). The persistent sheaths are yellow-speckled along their full lengths and without transparent shoulders, dry and membranous at the margins. The sheaths are tightly wrapped around the culms.
The species distribution is in the Northern Cape, Western Cape and Eastern Cape from the Richtersveld to the Cape Peninsula and Makhanda (Grahamstown).
The habitat is well-drained quartzite and sandstone soils on rocky slopes at elevations from 50 m to 1800 m, often among fynbos. The species is not considered to be threatened in its habitat early in the twenty first century (Dorrat-Haaksma and Linder, 2012; Leistner, (Ed.), 2000; JSTOR; iNaturalist; http://redlist.sanbi.org).