Uebelmannia pectinifera is a solitary cactus 10-50(-100) cm tall. It is a multiform species and very variable in habitat, comprising a complex of numerous local forms, where each form is linked to others by populations of plants with intermediate characteristics. Three subspecies are recognized, the nominate form (subsp. pectinifera), subsp. flavispina (Buining & Brederoo) P.J.Braun & Esteves and subsp. horrida (P.J. Braun) P.J. Braun & Esteves. The circumscription into subspecies possibly represents convenient over-simplification of the situation in nature. Solitary or (rarely) aggregated, globular to fusiform or elongated or cylindrical, it is reported to grow to as much as 1 m tall and 10-15(-17) cm wide with gummiferous ducts under the epidermis. The epidermis is dark reddish-green to reddish-brown or green to grey-green, with or without waxy plates and rough. In cultivation the colour of the plants depends on sun exposure, the plants grown in shadow are green with white stripes, while the ones in full sun take on a dark frost brown or purple colour.
Pot 10.5 cm