''Hoodia'' (; known locally as "ghaap" or "bobbejaanghaap") is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Apocynaceae Apocynaceae (from ''Apocynum'', Greek for "dog-away") is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly known as the dogbane family, because some taxa were used as dog poison Members of ...

, under the subfamily

Asclepiadoideae The Asclepiadoideae are a subfamily of plants in the family Apocynaceae. Formerly, they were treated as a separate family under the name Asclepiadaceae, e.g. by APG II, and known as the milkweed family. They form a group of perennial herbs, twi ...

, native to

Southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number o ...

. One species of ''Hoodia'' in particular, ''

Hoodia gordonii ''Hoodia gordonii'', also known as Bushman’s hat, is a leafless spiny succulent plant supposed to have therapeutic properties in folk medicine. It grows naturally in Botswana, South Africa and Namibia. The species became internationally known ...

'', has achieved a degree of fame and controversy, after being investigated for use as a possible appetite suppressant.

Description

The group was first described as a genus in 1844. Hoodia are

stem succulent Stem succulents are fleshy succulent columnar shaped plants which conduct photosynthesis mainly through their stems rather than their leaves.Frerea indica, a Stem Succulent CAM Plant with Deciduous C₃ Leaves, Otto L. Lange and Margit Zuber, Oec ...

s, described as "cactiform" because of their remarkable similarity to the unrelated

cactus A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Gree ...

family. They have a branching, shrub-like form, and the largest species ('' Hoodia parviflora'') can grow to the size of a tree — over in height. The flowers are extremely variable in size — from less than 1 cm, to almost 20 cm in diameter, depending on the species. Flowers appear in large numbers, always near the tops of the stems. Those of larger-flowered species (such as ''

'') are often a papery pink-tan colour, plate-shaped, with an unpleasant smell to attract their fly pollinators. The smaller, darker flowers of some species have a far stronger and more unpleasant smell than the larger flowers.

Distribution

The genus ''Hoodia'' is restricted to the arid regions in the western part of

southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number o ...

, ranging from western

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

to central

Namibia Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...

and as far north as southern

Angola , national_anthem = " Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...

. It is especially common in the

Namib desert The Namib ( ; pt, Namibe) is a coastal desert in Southern Africa. The name is of Khoekhoegowab origin and means "vast place". According to the broadest definition, the Namib stretches for more than along the Atlantic coasts of Angola, Nami ...

and in the

Orange River The Orange River (from Afrikaans/Dutch: ''Oranjerivier'') is a river in Southern Africa. It is the longest river in South Africa. With a total length of , the Orange River Basin extends from Lesotho into South Africa and Namibia to the north ...

valley. Typical habitat is rocky slopes and open stone plains. Plants usually germinate in the shelter of bushes or rocks, but survive in the open as adult plants. ;Species Several of the small-flowered species of ''Hoodia'' were formerly in a separate genus, ''Trichocaulon'' ("ghaap"), but have been moved into the genus ''Hoodia'', and the two groups are now synonymous. Phylogenetic studies have shown the genus ''Hoodia'' to be monophyletic, and most closely related to the stapeliad genus '' Lavrania''. Marginally more distantly related is a sister branch of related genera including '' Larryleachia'', '' Richtersveldia'' and '' Notechidnopsis''.

Uses and horticulture

Supplement

'' is traditionally used by the

San people The San peoples (also Saan), or Bushmen, are members of various Khoe, Tuu, or Kxʼa-speaking indigenous hunter-gatherer cultures that are the first cultures of Southern Africa, and whose territories span Botswana, Namibia, Angola, Zambia ...

(Bushmen) of the Namib desert as an appetite suppressant as part of their

indigenous knowledge Traditional knowledge (TK), indigenous knowledge (IK) and local knowledge generally refer to knowledge systems embedded in the cultural traditions of regional, indigenous, or local communities. According to the World Intellectual Property Orga ...

about survival in the harsh desert conditions. In 2006, the plant became internationally known, after a marketing campaign falsely claimed that its use as a dietary supplement was an

appetite suppressant An anorectic or anorexic is a drug which reduces appetite, resulting in lower food consumption, leading to weight loss. By contrast, an appetite stimulant is referred to as orexigenic. The term is (from the Greek ''ἀν-'' (an-) = "without" ...

for weight loss. As of 2018, there is no high-quality

clinical research Clinical research is a branch of healthcare science that determines the safety and effectiveness ( efficacy) of medications, devices, diagnostic products and treatment regimens intended for human use. These may be used for prevention, treatm ...

showing that hoodia has actions as an appetite suppressant or is effective for weight loss. In a case of biopiracy, bioprospectors from South Africa’s Council for Scientific and Industrial Research (CSIR) realized that the plant was marketable and patented its use as an appetite suppressant without recognizing the Sans' traditional claims to the knowledge of the plant and its uses. The patent was later sold to

Unilever Unilever plc is a British multinational consumer goods company with headquarters in London, England. Unilever products include food, condiments, bottled water, baby food, soft drink, ice cream, instant coffee, cleaning agents, energy dri ...

, which marketed hoodia products as diet supplements. In 2003, the South African San Council entered into a benefit sharing agreement with CSIR in which they would receive from 6 to 8% of the revenue from the sale of ''Ho. gordonii'' products, money which would be deposited in a trust for all San peoples across Southern Africa.

Horticulture

Several species are grown as

garden A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate bot ...

plants, and one species, ''H. gordonii'', is being investigated for use as an appetite suppressant. However, in 2008, UK-based Unilever PLC, one of the largest packaged-food firms in the world, abandoned plans to use hoodia in a range of diet products. In a document on Unilever's website entitled "Sustainable Development 2008: An Overview", signed by Paul Polman, CEO, Unilever states: "During 2008, having invested 20 million oundsin R&D, Unilever abandoned plans to use the slimming extract hoodia in a range of diet products. We stopped the project because our clinical studies revealed that products using hoodia would not meet our strict standards of safety and efficacy." Many ''Hoodia'' species are protected plants. ''Hoodia'' is currently listed in Appendix II to the

Convention on International Trade in Endangered Species of Wild Fauna and Flora CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of intern ...

(CITES), which includes species not currently considered endangered but are at risk if trade is not controlled.

References

External links

Germplasm Resources Information Network: ''Hoodia''
{{Taxonbar, from=Q134234 Apocynaceae genera Flora of Southern Africa Succulent plants Taxa named by Joseph Decaisne