''Acanthosicyos horridus'' is an unusual melon that is endemic to the Namib desert. In English it is known as Nara, butter-nuts, or butterpips; in one of the Khoisan languages it is locally called or ("!" is pronounced with a click, somewhat like the "tsk" when English people are tutting, tsk-tsk).

Description

It is a

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...

, leafless, phreatophyte (meaning its roots penetrate deep down to water near the water table) that is found in sandy deserts but not stony plains, in areas with access to ground water such as

ephemeral river A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams ar ...

s and paleochannels, where sand accumulating in the shelter of its stems can form hummocks up to 1000–1500 m² in area and 4 meters in height. Its stems may rise more than a meter above the hummocks, while its system of thick taproots can extend up to 50 m downward. The plant is leafless, so modified stems and spines 2–3 centimetres long serve as the photosynthetic "organs" of the plant. The plant can survive many years without water.

Ecology

Its sand-binding characteristics also help nara form microclimate within the desert dunes. These microclimates provide food and shelter for a variety of vertebrates. Presence of the nara plant is associated with significantly increased soil microdiversity likely due to the shade it provides and the attraction of foraging mammals which contribute to organic matter. ''Acanthosicyos horridus'' typically occurs in the absence of other vegetation due to the harshness of the climate, though '' Eragrostis spinosa'' and ''

Stipagrostis sabulicola ''Stipagrostis sabulicola'', the Namib dune bushman grass, is a species of grass endemic to the dunes of the Namib The Namib ( ; pt, Namibe) is a coastal desert in Southern Africa. The name is of Khoekhoegowab origin and means "vast plac ...

'' grasses may grow between its hummocks. It is regarded as a

keystone species A keystone species is a species which has a disproportionately large effect on its natural environment relative to its abundance, a concept introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaini ...

because its melons, seeds, shoots, and flowers are food sources for beetles,

gemsbok The gemsbok or South African oryx (''Oryx gazella'') is a large antelope in the genus ''Oryx''. It is native to the extremely dry, arid regions of Southern Africa; notably, the Kalahari Desert. Some authorities formerly classified the East Afric ...

, and ostrich, while small rodents such as ''

Rhabdomys pumilio The four-striped grass mouse (''Rhabdomys pumilio'') or four-striped grass rat, is a species of rodent in the family Muridae. It is found throughout the southern half of Africa up to above sea level, extending as far north as the Democratic Rep ...

'', ''

Desmodillus auricularis The Cape short-eared gerbil (''Desmodillus auricularis'') is a species of rodent in the family Muridae. It is the only species in the genus ''Desmodillus''. It is found in Angola, Botswana, Namibia, and South Africa. Its natural habitat ...

'', and ''

Thallomys nigricauda The black-tailed tree rat, also called black-tailed acacia rat or black-tailed thallomys, (''Thallomys nigricauda''), is a species of rodent in the family Muridae. It is found in Angola, Botswana, Namibia and South Africa, where its natural hab ...

'' take shelter amid the spiny tangle of its stems. The

katydid Insects in the family Tettigoniidae are commonly called katydids (especially in North America), or bush crickets. They have previously been known as "long-horned grasshoppers". More than 8,000 species are known. Part of the suborder Ensifera, t ...

Acanthoproctus diadematus ''Acanthoproctus diadematus'' (Namibia katydid or Nara cricket) is an armoured katydid, bush-cricket, or ground cricket endemic to the Namib Desert of southern Africa, where it lives in the tall sand dunes along the Kuiseb River in Namib-Naukl ...

'' feeds on the plant, moving between different bushes at night.

Uses

The melon fruits average 1 kg and are pale green and spiny. Within it has a sweet, aromatic, watery, yellow-orange pulp. The large edible seeds, white to cream in color, are known as butter-nuts or butterpips. These have been exported for use in baked goods.Grubben, G.J.H. & Denton, O.A. (2004) Plant Resources of Tropical Africa 2. Vegetables. PROTA Foundation, Wageningen; Backhuys, Leiden; CTA, Wageningen. The fruit serves as a food source for

Nama people Nama (in older sources also called Namaqua) are an African ethnic group of South Africa, Namibia and Botswana. They traditionally speak the Nama language of the Khoe-Kwadi language family, although many Nama also speak Afrikaans. The Nama Peo ...

from February to April and August to September.

References

External links

PROTAbase on ''Acanthosicyos horridus''
* {{Authority control Cucurbitoideae Endemic flora of Namibia Desert fruits Drought-tolerant plants Taxa named by Joseph Dalton Hooker Taxa named by George Bentham Plants described in 1867

Description

Ecology

Uses

See also

References

External links