''Adenia'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s in the passionflower family Passifloraceae. It is distributed in the

Old World The "Old World" () is a term for Afro-Eurasia coined by Europeans after 1493, when they became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia in the Eastern Hemisphere, previously ...

tropics The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

and

subtropics The subtropical zones or subtropics are geographical and climate zones immediately to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately ...

.''Adenia''.
Flora of China. The centers of diversity are in Madagascar, eastern and western tropical Africa, and Southeast Asia. The genus name ''Adenia'' comes from "aden", reported as the Arabic name for the plant by

Peter Forsskål Peter Forsskål, sometimes spelled Pehr Forsskål, Peter Forskaol, Petrus Forskål or Pehr Forsskåhl (11 January 1732 – 11 July 1763) was a Sweden, Swedish exploration, explorer, oriental studies, orientalist, natural history, naturalist, and ...

, the author of the genus.

Description

All ''Adenia'' are

perennial plant In horticulture, the term perennial (''wikt:per-#Prefix, per-'' + ''wikt:-ennial#Suffix, -ennial'', "through the year") is used to differentiate a plant from shorter-lived annual plant, annuals and biennial plant, biennials. It has thus been d ...

s, but there are many different forms, including herbs, vines, shrubs, and trees. Many are succulents and some are pachycauls. Some have fibrous root systems and some have

tuber Tubers are a type of enlarged structure that plants use as storage organs for nutrients, derived from stems or roots. Tubers help plants perennate (survive winter or dry months), provide energy and nutrients, and are a means of asexual reproduc ...

s. ''Adenia'' can be found in a wide variety of habitat types, from dry African deserts to wet Southeast Asian rainforests. There are about 100 species in the genus. ''Adenia'' have alternately arranged leaves borne on petioles. There are two glands located near the attachment of the leaf blade to the petiole. Most species are

dioecious Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

Inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s of a few to many flowers occur in the leaf axils. There is a stipe below the flower. The calyx has five lobes and the five

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s are usually smaller than the

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

s and may be whitish or greenish. The male flower has five

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s. In the female flower these are reduced to

staminode In botany, a staminode is an often rudimentary, sterile or abortive stamen, which means that it does not produce pollen.Jackson, Benjamin, Daydon; ''A Glossary of Botanic Terms with their Derivation and Accent''; Published by Gerald Duckworth & Co ...

s. There are three styles tipped with stigmas that may be long-hairy to very woolly. The fruit is a red capsule. Each black seed has a fleshy

aril An aril (), also called arillus, is a specialized outgrowth from a seed that partly or completely covers the seed. An arillode, or false aril, is sometimes distinguished: whereas an aril grows from the attachment point of the seed to the ova ...

. ''Adenia'' species can be difficult to identify and distinguish as individuals of a species can be variable. One plant can have leaves of varying shapes and sizes, and young and old specimens can have different leaf types. Some taxa are poorly represented in

herbarium A herbarium (plural: herbaria) is a collection of preserved plant biological specimen, specimens and associated data used for scientific study. The specimens may be whole plants or plant parts; these will usually be in dried form mounted on a sh ...

collections, leaving few examples to compare with new specimens. Records of some taxa lack descriptions of both (i.e. male and female) flower types. Many species only flower for a few weeks, and during this time they may also lose their leaves. Succulent plants can be difficult to properly collect and preserve.

Cytology

The chromosome count of ''Adenia'' is 2n = 24 or 2n = 48.Melo, N. F. D., & Guerra, M. (2021)
"The karyotype of ''Adenia'' and the origin of the base number x= 12 in Passifloroideae (Passifloraceae)."
Anais da Academia Brasileira de Ciências, 93.

Uses

Several species are used in

traditional African medicine Traditional African medicine is a range of traditional medicine disciplines involving indigenous herbalism and African spirituality, typically including diviners, midwives, and herbalists. Practitioners of traditional African medicine claim, ...

. Various parts of ''A. cissampeloides'' are used to treat many conditions, including gastrointestinal problems, inflammation, pain, fever, malaria, leprosy, scabies, cholera, anemia, bronchitis, sexually transmitted diseases, menorrhagia, and mental illness.Grace, O. M. and D. Fowler. 2007
''Adenia cissampeloides'' (Planch. ex Hook.) Harms.
In: Schmelzer, G. H. and A. Gurib-Fakim (Eds.) Prota 11(1): Medicinal Plants/''Plantes médicinales'' 1. PROTA, Wageningen, Netherlands. It is used both as an

abortifacient An abortifacient ("that which will cause a miscarriage" from Latin: '' abortus'' "miscarriage" and '' faciens'' "making") is a substance that induces abortion. This is a nonspecific term which may refer to any number of substances or medications, ...

and to prevent miscarriage. ''A. dinklagei'' leaves are ingested to treat palpitations. The leaves of ''A. tricostata'' are used to treat fever. The leaves or leaf sap of ''A. bequaertii'' are taken to treat headache, mental illness, and possession. ''A. lobata'' stems are applied to sites of Guinea worm infection during extraction of the worm. It is also used as an enema and an aphrodisiac.Zimudzi, C. 2007
''Adenia lobata'' (Jacq.) Engl.
In: Schmelzer, G. H. and A. Gurib-Fakim (Eds.) Prota 11(1): Medicinal Plants/''Plantes médicinales'' 1. PROTA, Wageningen, Netherlands. ''A. cissampeloides'' is used as a fish poison and arrow poison. The red-colored sap is used as a cosmetic. The stems can be made into rope. The crushed twigs or smoke from burning roots can be used to calm honeybees during honey harvest. The leaves of ''A. cissampeloides'' are eaten as a vegetable in parts of Africa. ''A. digitata'' is cultivated as an ornamental plant for its very large, distinctive aboveground tuber.de Ruijter, A. 2007
''Adenia digitata'' (Harv.) Engl.
In: Schmelzer, G. H. and A. Gurib-Fakim (Eds.) Prota 11(1): Medicinal Plants/''Plantes médicinales'' 1. PROTA, Wageningen, Netherlands.

Toxicity

Many ''Adenia'' are poisonous. They contain

lectin Lectins are carbohydrate-binding proteins that are highly specific for sugar Moiety (chemistry), groups that are part of other molecules, so cause agglutination (biology), agglutination of particular cells or precipitation of glycoconjugates an ...

s such as lanceolin, stenodactylin, and volkensin, which are toxic to cells. They cause

apoptosis Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biol ...

, hemagglutination, inhibition of protein synthesis, and

depurination Depurination is a chemical reaction of purine deoxyribonucleosides, deoxyadenosine and deoxyguanosine, and ribonucleosides, adenosine or guanosine, in which the β-N-glycosidic bond is hydrolytically cleaved releasing a nucleic base, adenine or ...

ribosome Ribosomes () are molecular machine, macromolecular machines, found within all cell (biology), cells, that perform Translation (biology), biological protein synthesis (messenger RNA translation). Ribosomes link amino acids together in the order s ...

s and

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

. Mouse experiments with small doses of lanceolin and stenodactylin, from ''A. lanceolata'' and ''A. stenodactyla'', respectively, revealed that they are "amongst the most potent toxins of plant origin". The fruit of ''A. digitata'' has been used in Africa to commit homicide and suicide.

Species

The following is a list of all 106 species in this genus that are accepted by

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

Description

Cytology

Uses

Toxicity

Species

References

Further reading