Othonna macrophylla is a hairless perennial growing from tuberous roots. The erect stem is simple or forked, curving or straight, soft and fleshy. When the inflorescence is present the plant may be up to 60 cm in height.

The species is endemic to Namaqualand in the Northern Cape. The plants grow in stony, sandy soil, often among larger shrubbery. It is not considered to be threatened in its habitat early in the twenty first century (iNaturalist; JSTOR; http://redlist.sanbi.org).