Muiria hortenseae ("mouse-head") is a rare dwarf species of succulent plant of the iceplant family (Aizoaceae), indigenous to a very small area in the Little Karoo, Western Cape, South Africa.

Unlike most other plants in its family, Muiria is covered in soft downy fur (from which it gets its common name) and has leaves that are entirely fused together, into one smooth rounded body.

With the onset of the full summer drought, flowering ends, the old flesh gradually dries into a papery sheath and the plants enter a brief dormancy which can last any period between a few weeks and four months.

Muiria is indigenous to a tiny arid area (c.300 mm annual rainfall) of the "Succulent Karoo" in the Western Cape, South Africa.

[2] Muiria hortenseae is difficult to cultivate, as it requires sparing but steady watering throughout most of the year, (a sharply contrasting opinion is that of Alfred Byrd Graf who recommends that Muiria hortense be watered only once a year)[3] generous space for its large root system, and a rocky, gritty, extremely well-drained soil.