The evergreen, unbranched culms or stems of Askidiosperma andreaeanum are solid, smooth and cylindrical. Several slightly transparent, pale sheathes, from 2 cm to 4 cm long envelop the stems at the nodes, spaced at wide intervals. The sheaths have entire margins. When they drop off, dark abscission rings remain at each bare culm node.
The stem-clumps become large when the plant escapes fire, the core surviving fire for resprouting later from the rhizome, faster than the new plants can grow from seed.
The Askidiosperma genus comprises 12 species. A. andreaeanum is similar to A. paniculatum that flowers in autumn but more sparsely (Dorrat-Haaksma and Linder, 2012; iNaturalist; http://pza.sanbi.org).