''Inga edulis'', known as ice-cream bean, ice-cream-bean, joaquiniquil, cuaniquil (both from

Nahuatl Nahuatl ( ; ), Aztec, or Mexicano is a language or, by some definitions, a group of languages of the Uto-Aztecan language family. Varieties of Nahuatl are spoken by about Nahuas, most of whom live mainly in Central Mexico and have smaller popul ...

: ''cuahuxinicuile'' combining ''cuahuitl'' "tree"; ''icxitl'' "feet" and ''necuilli'' "crooked") guama or guaba, is a fruit native to

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. It is in the mimosoid tribe of the legume family

Fabaceae Fabaceae () or Leguminosae,International Code of Nomen ...

. It is widely grown, especially by

Indigenous Indigenous may refer to: *Indigenous peoples *Indigenous (ecology) In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often populari ...

Amazonians, for shade, food, timber, medicine, and production of the alcoholic beverage cachiri. It is popular in

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

Pernambuco Pernambuco ( , , ) is a States of Brazil, state of Brazil located in the Northeast Region, Brazil, Northeast region of the country. With an estimated population of 9.5 million people as of 2024, it is the List of Brazilian states by population, ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, Venezuela, Guyana and

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

. The taxonomic name ''Inga'' is derived from its name with the

Tupí people The Tupi people, a subdivision of the Tupi-Guarani linguistic families, were one of the largest groups of indigenous peoples in Brazil before its colonization. Scholars believe that while they first settled in the Amazon rainforest, from abo ...

of South America (''ingá'') while the species name '' edulis'' is Latin for "edible". The common name "ice-cream bean" alludes to the sweet flavor and smooth texture of the pulp.

Biology

Mature trees of ''I. edulis'' reach 30 m (98 ft) high and 60 cm (2.0 ft) diameter at breast height, usually branching from below 3 m (9.8 ft). The branches form a broad, flat, moderately dense canopy. ''Inga edulis'' can be evergreen in tropical regions or deciduous when planted in colder regions. The tree has a pale grey coloured trunk. The stems and young twigs can be sparsely to densely haired. The leaves are alternate, evenly

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and ...

, 10–30 cm long with 4–6 pairs of opposite, dark-green, membranous, slightly pubescent, oval leaflets. The terminal leaflets can grow up to 18 cm long by 11 cm wide in comparison to the basal ones. Extrafloral

nectaries Nectar is a viscous, sugar-rich liquid produced by plants in glands called nectaries, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists, ...

are placed on petioles and

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole (botany), petiole). They are primarily found among dicots and rare among monocots. Stipules are considered part ...

s can be either inconspicuous, absent, or caducus. Flowers are fragrant, sessile, pentamerous and are arranged in dense axillary spikes. The flower has a calyx tube with five puberulent, striate lobes, corolla with five silky, villous petals. These are around 14–20 mm long and contain numerous white

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. The fruits are longitudinally ribbed, cylindrical indehiscent

leguminous Legumes are plants in the pea family Fabaceae (or Leguminosae), or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consum ...

pods which can be straight, curved or often spirally twisted up. They are pendant and up to 1 m long and yellowish brown to greenly coloured. The amount of ovoid seeds can vary from 10 to 20, which are purplish-black to olive colored. These are embedded in the sweet, cottony, white

arillus 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 ...

which gives it the name Icecream bean, since they taste sweet.

Symbiosis

''Inga'' species are symbiotic with ants (e.g., ''

Pheidole ''Pheidole'' () is a genus of ants that belongs to the ant subfamily Myrmicinae. The genus is widespread and ecologically dominant. Many species in the genus first evolved in the Americas, while some, such as ''Pheidole indica'' and '' Pheidole m ...

'' spp.), which feed on the nectar of the extrafloral nectaries. In exchange the ants will patrol over the Inga plant to protect it against

herbivore A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...

s. There are certain insects such as Riodinid caterpillars which excrete sugary honeydew from their tentacle nectaries. The ants will form a symbiosis with the caterpillars by letting them feed on the tree and in favour of getting sugary honeydew from them. The Inga plant can also form symbiotic relationships where nitrogen gas can be fixated by

rhizobia Rhizobia are diazotrophic bacteria that fix nitrogen after becoming established inside the root nodules of legumes (Fabaceae). To express genes for nitrogen fixation, rhizobia require a plant host; they cannot independently fix nitrogen. I ...

l bacteria and

mycorrhiza A mycorrhiza (; , mycorrhiza, or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, the plant root system and its surroundings. Mycorrhizae play ...

as other legumes can. Surveys have shown that ''I. edulis'' undergo a mutualistic relationships with the bacterial strain of ''

Bradyrhizobium ''Bradyrhizobium'' is a genus of Gram-negative bacteria, Gram-negative soil bacteria, many of which fix nitrogen. Nitrogen fixation is an important part of the nitrogen cycle. Plants cannot use atmospheric nitrogen (N2); they must use nitrogen co ...

''. File:Inga Flowers.JPG, Flowers File:Inga edulis, mature and juvenile Guama pods (10108341614).jpg, Mature and young pods

Synonyms

This plant has a convoluted history of

synonymy A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

with ''

Inga vera ''Inga'' is a genus of small tropical, tough-leaved, nitrogen-fixing treesElkan, Daniel. "Slash-and-burn farming has become a major threat to the world's rainforest" ''The Guardian'' 21 April 2004 and shrubs, subfamily Mimosoideae. ''Inga''s l ...

''. The plants discussed under that name by Brenan and

Kunth Carl Sigismund Kunth (18 June 1788 – 22 March 1850) was a German botanist. He was also known as Karl Sigismund Kunth or anglicized as Charles Sigismund Kunth. He was one of the early systematic botanists who focused on studying the plants of th ...

are actually ''I. edulis'', whereas that based on the writings of

Carl Ludwig Willdenow Carl Ludwig Willdenow (22 August 1765 – 10 July 1812) was a German botanist, pharmacist, and plant Taxonomy (biology), taxonomist. He is considered one of the founders of phytogeography, the study of the geographic distribution of plants. ...

refers to the actual ''I. vera''. ''Inga edulis'' in works referring back to authorities other than

von Martius Carl Friedrich Philipp (Karl Friedrich Philipp) von Martius (17 April 1794 – 13 December 1868) was a German botanist and explorer. Between 1817 and 1820, he travelled 10,000 km through Brazil while collecting botanical specimens. His most impo ...

usually refers to '' Inga feuilleei''.ILDIS (2005) Synonyms of ''Inga edulis'' Mart.: *''Feuilleea edulis'' (Mart.) Kuntze *''Inga benthamiana''

Meisn. Carl Daniel Friedrich Meissner (1 November 1800 – 2 May 1874) was a Swiss botanist. Biography Born in Bern, Switzerland on 1 November 1800, he was christened Meisner but later changed the spelling of his name to Meissner. For most of his 40 ...

*''Inga edulis''

var. In botanical nomenclature, variety (abbreviated var.; in ) is a taxonomic rank below that of species and subspecies, but above that of Form (botany), form. As such, it gets a three-part Infraspecific name (botany), infraspecific name. It is s ...

''grenadensis'' Urb. *''Inga minutula'' (Schery) T.S.Elias *''Inga scabriuscula'' Benth. *''Inga vera'' Kunth *''Inga vera'' ''sensu'' Brenan *''Inga ynga'' (Vell.) J.W.Moore *''Mimosa inga'' L. *''Mimosa ynga'' Vell.

Ecology

The natural distribution of ''I. edulis'' spreads from Central to

and ranges from subtropical dry to tropical wet conditions. It can be found at elevations from sea level up to 2200 m. ''Inga edulis'' grows best when mean annual daytime temperature ranges from 23 to 30 °C. However, it can tolerate 18–35 °C. During the resting period mature trees can survive −2 °C while young plants are killed at 0 °C. Preferred

annual precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwealth ...

ranges from 1200 to 2500 mm but 640 to 4000 mm of annual precipitation can be tolerated also. It can be grown on a widely varying range of soil conditions. It prefers a

soil pH Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. Soil pH is a key characteristic that can be used to make informative analysis both qualitative and quantitatively regarding soil characteristics. pH is defined as the neg ...

of 5–6.5 but can also grow in very strongly acidic soil down to a pH of 4.5 or moderately alkaline conditions up to pH 8. The natural habitat includes margins of large rivers like the

Amazon Amazon most often refers to: * Amazon River, in South America * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon (company), an American multinational technology company * Amazons, a tribe of female warriors in Greek myth ...

, thickets below high water line and wooded swamps. Therefore, the tree tolerates temporarily waterlogged soils for 2–3 months each year. However, it can also tolerate drought seasons up to 6 months. Furthermore, ''I. edulis'' can cope with heavy soils or slope fairly well. In terms of soil fertility, ''I. edulis'' is not only unpretentious but has the potential to improve

soil quality Soil quality refers to the condition of soil based on its capacity to perform ecosystem services that meet the needs of human and non-human life.Tóth, G., Stolbovoy, V. and Montanarella, 2007. Soil Quality and Sustainability Evaluation - An integ ...

. As a leguminous tree, this species can compensate for nutrient depleted soils by fixing nitrogen with its root nodules. Ammonium and nitrates found in soil typically result in nodulation reduction. ''Inga edulis i''s an exception, as its nodules increase in size when ammonium levels are at 5mM. Nitrate on the other hand did not benefit ''I. edulis'' and continued to show properties that prevented nodulation. Additionally to nitrogen, ''I. edulis'' is reported to significantly increase the extractable

phosphorus Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...

content in the soil and thus further ameliorates degraded soils.

Cultivation

''Inga edulis'' is widely cultivated in

agroforestry Agroforestry (also known as agro-sylviculture or forest farming) is a land use management system that integrates trees with crops or pasture. It combines agricultural and forestry technologies. As a polyculture system, an agroforestry system c ...

systems in its

neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeogra ...

dispersal area. This form of cultivation, often associated with

coffee Coffee is a beverage brewed from roasted, ground coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content, but decaffeinated coffee is also commercially a ...

cocoa Cocoa may refer to: Chocolate * Chocolate * ''Theobroma cacao'', the cocoa tree * Cocoa bean, seed of ''Theobroma cacao'' * Chocolate liquor, or cocoa liquor, pure, liquid chocolate extracted from the cocoa bean, including both cocoa butter and ...

culture, is widely known since

pre-Columbian In the history of the Americas, the pre-Columbian era, also known as the pre-contact era, or as the pre-Cabraline era specifically in Brazil, spans from the initial peopling of the Americas in the Upper Paleolithic to the onset of European col ...

times.

Germination Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ...

of ''I. edulis'' seeds is fairly easy as the seeds are recalcitrant and often germinate already in the pod. However, seeds lose their ability to germinate after two weeks of storage. Direct sowing of the seeds is possible, but the establishment of seedlings with already a certain height can decrease

competition Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indi ...

with noxious weeds and thus increase growth. Further, the inoculation with

and

l fungi in depleted soils is recommended to promote growth. These inoculi can easily be produced by collecting soil, nodules and fine roots from mature, nodulated ''I. edulis'' stands. This species seems to be very resistant to pests and diseases. Minor damage can result from fungal attacks in the seedling stage. Mature ''I. edulis'' can be defoliated by

Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

larvae. Also, fruit fly larvae often damage the seed testa. In

, ''I. edulis'' is specially susceptible to

mistletoe Mistletoe is the common name for obligate parasite, obligate parasitic plant, hemiparasitic plants in the Order (biology), order Santalales. They are attached to their host tree or shrub by a structure called the haustorium, through which they ...

infestations.

Uses

Food crop ''Inga edulis'' has been cultivated as a

fruit tree A fruit tree is a tree which bears fruit that is consumed or used by animals and humans. All trees that are flowering plants produce fruit, which are the ripened ovaries of flowers containing one or more seeds. In horticultural usage, the te ...

for millennia and is widely sold on the local South American marketplace, mainly for the sweet, succulent pulp surrounding the seeds. The white pulp (

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 ...

) is consumed raw as a sweet snack, though it is less nutritious than the seeds. Toxic compounds such as

trypsin Trypsin is an enzyme in the first section of the small intestine that starts the digestion of protein molecules by cutting long chains of amino acids into smaller pieces. It is a serine protease from the PA clan superfamily, found in the dig ...

and

chymotrypsin Chymotrypsin (, chymotrypsins A and B, alpha-chymar ophth, avazyme, chymar, chymotest, enzeon, quimar, quimotrase, alpha-chymar, alpha-chymotrypsin A, alpha-chymotrypsin) is a digestive enzyme component of pancreatic juice acting in the duodenu ...

inhibitors contained in the seeds of ''I. edulis'' are destroyed through cooking.The taste is described as resembling that of

vanilla ice cream Vanilla is frequently used to flavor ice cream, especially in North America, Asia, and Europe. Vanilla ice cream, like other flavors of ice cream, was originally created by cooling a mixture made of cream, sugar, and vanilla above a container ...

. Some varieties even possess a slight cinnamon flavor. The seeds are only edible when cooked and have a taste similar to that of

chickpeas The chickpea or chick pea (''Cicer arietinum'') is an annual legume of the family Fabaceae, subfamily Faboideae, cultivated for its edible seeds. Its different types are variously known as gram," Bengal gram, garbanzo, garbanzo bean, or Egypt ...

. In

the

s are also used to prepare an

alcoholic beverage Drinks containing alcohol (drug), alcohol are typically divided into three classes—beers, wines, and Distilled beverage, spirits—with alcohol content typically between 3% and 50%. Drinks with less than 0.5% are sometimes considered Non-al ...

called cachiri for a festival of the same name. The native women chew the arils and spit the mixture into a vat, where it is left to ferment. The fruit ripens quickly and can only be kept for three to four days, limiting potential export opportunities. However, refrigeration can extend

shelf life Shelf life is the length of time that a commodity may be stored without becoming unfit for use, consumption, or sale. In other words, it might refer to whether a commodity should no longer be on a pantry shelf (unfit for use), or no longer on a s ...

to about three weeks. Use in agroforestry systems Due to its rapid growth and ability to improve soil properties, ''I. edulis'' has found widespread use in tropical

. Most notably,

Inga alley cropping Agroforestry (also known as agro-sylviculture or forest farming) is a land use management system that integrates trees with crops or pasture. It combines agricultural and forestry technologies. As a polyculture system, an agroforestry system can ...

is used as an alternative to slash and burn cultivation. It is also a popular shade tree for

and

tea Tea is an aromatic beverage prepared by pouring hot or boiling water over cured or fresh leaves of '' Camellia sinensis'', an evergreen shrub native to East Asia which probably originated in the borderlands of south-western China and nor ...

plantations. One important reason for this is that in comparison to other

shade tree A shade tree is a large tree whose primary role is to provide shade in the surrounding environment due to its spreading canopy and crown, where it may give shelter from sunlight in the heat of the summer for people who seek recreational needs i ...

species ''I. edulis'' retains its leaves in the dry season. Cuttings and leaves also used as mulch and animal fodder. The wood is sometimes used as timber and for fuel, its popularity as a source of firewood stemming from its high calorific value and weak smoke production. Despite its rapid growth and significant potential to improve soils in agroforestry systems, ''I. edulis'' has not been the object of any improved breeding program. However, the plant has been shown to exhibit strong

introgression Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Introg ...

with ''I. ingoides'' in species contact areas. This could allow for selection of hybrids via interspecific hybridization to further increase yield and flood tolerance of the crop. Medicinal uses ''Inga edulis'' is widely used in native South American folk medicine. Decoctions of the leaves, bark or root commonly are utilized as treatments for diarrhea, arthritis and rheumatism. Crushed, boiled leaves are ingested to relieve coughing or applied to lip sores, possibly caused by

herpes Herpes simplex, often known simply as herpes, is a viral infection caused by the herpes simplex virus. Herpes infections are categorized by the area of the body that is infected. The two major types of herpes are oral herpes and genital herp ...

. Several studies have investigated ''I. edulis'' as a source of

polyphenols Polyphenols () are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as ...

for use as

antioxidant Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants ...

s and have shown promising results. However, further studies are necessary to test and develop medical applications.

References

Ice Cream Beans
* (1983)

Version of 07-JAN-1998. Retrieved 2007-DEC-17. * (2005)
Genus ''Canavalia''
Version 10.01, November 2005. Retrieved 2007-DEC-17. * (2007): Germplasm Resources Information Network �
''Inga edulis''
Retrieved 2007-DEC-18. {{Taxonbar, from=Q138183 edulis Edible legumes Flora of Southern America Tropical fruit Trees of Peru