''Muiria hortenseae'' ("mouse-head") is a rare dwarf species of

succulent plant In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...

of the family

Aizoaceae The Aizoaceae, or fig-marigold family, is a large family of dicotyledonous flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is d ...

, indigenous to a very small area in the

Little Karoo The Karoo ( ; from the Afrikaans borrowing of the South Khoekhoe !Orakobab or Khoemana word ''ǃ’Aukarob'' "Hardveld") is a semi-desert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its ext ...

Western Cape The Western Cape is a province of South Africa, situated on the south-western coast of the country. It is the fourth largest of the nine provinces with an area of , and the third most populous, with an estimated 7 million inhabitants in 2020 ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

. It is the only species in the monophyletic genus ''Muiria''.

Description

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. In the summer it produces white or pink flowers, that tear through the (still living) flesh of the plant. The flesh then withers into a papery sheath, within which the new body forms. After several generations of subdivisions, it can form clumps.

Life-cycle

Like many related plants, Muirias grow in annual cycles of growth and dormancy. Their habitat is a winter rainfall region. They therefore begin their growth cycle in early

autumn Autumn, also known as fall in American English and Canadian English, is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September ( Northern Hemisphere) or March ( Sou ...

when the first rains arrive, pushing out of the dry sheaths which remain from the previous years dead leaves, and forming the new green growth. Throughout the

winter Winter is the coldest season of the year in polar and temperate climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Different cultures ...

, they receive mists and occasional rainfall. By the end of winter, the new growth stops and appears to decay, becoming more yellow and soft in the

spring Spring(s) may refer to: Common uses * Spring (season), a season of the year * Spring (device), a mechanical device that stores energy * Spring (hydrology), a natural source of water * Spring (mathematics), a geometric surface in the shape of a ...

. The flower buds can then push through the softened flesh. With the onset of the full

summer Summer is the hottest of the four temperate seasons, occurring after spring and before autumn. At or centred on the summer solstice, the earliest sunrise and latest sunset occurs, daylight hours are longest and dark hours are shortest, wit ...

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). The first new rains bring it out of dormancy and commence the cycle again.

Distribution and habitat

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

. Its habitat is the quartzite rubble that overlay clay soils on the low ridges near the

Langeberg The Langeberg Range is a mountain range in the Western Cape province of South Africa. Its highest peak is Keeromsberg at 2,075 m that lies 15 km northeast of the town of Worcester. Some of the highest peaks of the range are located just to ...

Mountains. In this extremely small range, it has recently suffered an enormous reduction in population and range, due to habitat loss, trampling by stock animals and illegal collecting.

Cultivation

''Muiria hortenseae'' is difficult to cultivate, as it requires sparing but steady watering throughout most of the year, generous space for its large root system, and a rocky, gritty, extremely well-drained soil. Some cultivators also occasionally add a one or two grains of salt to the soil surface, to add an extremely slight salinity to the soil. It is also recommended to give it little to no water for a drought of a month or two, after it has flowered. Propagation is usually by seed, and ''Muiria'' sometimes hybridises with '' Gibbaeum album'', with which it shares its natural habitat in the

References

External links

* * Aizoaceae Monotypic Caryophyllales genera Aizoaceae genera Taxa named by N. E. Brown {{Aizoaceae-stub