It grows as an annual herb from 7 to 40 centimetres in height, with green or white flowers.

Individual plants bear both perfect and imperfect flowers.

[3] This species was published in 1786 by Georg Forster, based on a type specimen collected in New Zealand.

[5][6] In Australia it is widespread in temperate regions, occurring in every state and territory.

[3][7] DNA was able to be extracted, and the chloroplast DNA trnL–trnF intergenic spacer and trnL intron were sequenced, from a herbarium specimen of Parietaria debilis collected by Joseph Banks and Daniel Solander on Captain James Cook’s first voyage in 1769–70.