What Is the Fruit Family of the Mango and Its Relatives?

The mango belongs to the plant family Anacardiaceae, a group of roughly 80 genera and over 800 species that includes an unexpectedly wide roster of economically important plants: cashews, pistachios, pink peppercorns, sumac, marula fruit, and even poison ivy. Often called the “cashew family” in English, Anacardiaceae is defined in part by the resin-filled ducts running through its members’ bark, leaves, and fruit, which produce everything from lacquer to urushiol, the compound behind poison ivy rashes. The family’s edible fruits span a startling range of shapes, sizes, and flavors, yet they share underlying features that mark them as relatives.

What Ties These Plants Together

Anacardiaceae sits within the larger order Sapindales, alongside citrus (Rutaceae) and lychee (Sapindaceae). Despite the variety among its members, the family has a few consistent structural hallmarks. The flowers tend to reduce to a single fertile carpel, particularly in the subfamily Anacardioideae, which includes mango and cashew. That single carpel typically produces a drupe: a fruit with a fleshy outer layer surrounding a hard pit that encloses a seed. Mangoes, cashews, and pistachios all fit this pattern in their own ways, even when the part you eat looks nothing alike from fruit to fruit.¹

The other hallmark is those resin ducts. All Anacardiaceae produce resins from secretory ducts lined with a single-layered epithelium. These ducts fuse laterally and branch throughout the plant body, forming connected networks from root to fruit. In the fruit itself, new ducts form as the flesh develops, which is why slicing open a mango releases aromatic, slightly sticky juice, and why cashew shells ooze a caustic oil. The chemical cocktail in these ducts varies across genera but shares a family resemblance: phenolic compounds, terpenes, and in many cases urushiol or related irritants.²

The Genus Mangifera and Its Wild Relatives

The common mango you find at the grocery store is Mangifera indica, but it is just one of about 69 recognized species in the genus Mangifera, most of which grow wild in the tropical forests of Southeast Asia. Many of these wild relatives produce edible fruit of their own, though they rarely appear outside regional markets. Species like M. foetida (commonly called horse mango or bachang), M. laurina, and M. quadrifida are eaten locally and represent a reservoir of genetic diversity that breeders consider valuable for disease resistance and flavor variety.

Phylogenetic work on the genus has revealed that these species cluster into several distinct groups. The common mango (M. indica) is closely related to M. laurina but distantly related to species like M. quadrifida and M. similis.³ Genome resequencing of cultivated mangoes has also shown that the commercial varieties most people eat cluster with Indian germplasm, while a separate group of indigenous varieties from Southeast Asia forms its own distinct lineage. Chinese landraces sit apart from both, with some showing signs of genetic mixing between the two main groups.⁴ This matters practically because the narrow genetic base of commercial mango makes the crop vulnerable to disease, and those wild or semi-wild relatives could offer useful traits if they can be crossed with cultivated lines.

Cashews Are Stranger Than They Look

The cashew (Anacardium occidentale) is perhaps the best illustration of how creatively Anacardiaceae structures can diverge from the mango blueprint while still following the same underlying rules. What most people call the “cashew apple” is not the fruit at all but a swollen, fleshy stem (technically a pseudofruit or accessory fruit). The true fruit is the kidney-shaped cashew nut hanging off the bottom, which is a single-seeded drupe just like a mango pit, only much smaller and encased in a caustic shell. That shell contains anacardic acid, a chemical cousin of urushiol, which is why cashews must be roasted or steamed before they can be eaten safely.

The cashew nut kernel is protein- and fat-rich, averaging around 23 grams of protein and 52 grams of fat per 100 grams. The cashew apple, which is juiced and eaten in parts of Brazil and other producing countries, is a good source of potassium and phosphorus.⁵ Because the apple bruises easily and ferments quickly, it rarely travels far from where it is harvested, which is why most of the world knows only the nut.

Pistachios and the Allergy Connection

Pistachios (Pistacia vera) belong to the same family, in the genus Pistacia, which also includes the mastic tree (P. lentiscus), the source of the aromatic resin used in Greek cooking and traditional varnishes. Despite being marketed alongside almonds and walnuts, pistachios are botanically closer to mangoes and cashews than to any tree nut outside Anacardiaceae.

This botanical kinship has practical consequences for people with food allergies. In a study of children who were sensitized to cashew nut, roughly 98% were also sensitized to pistachio, and about 21% were co-sensitized to mango. That extremely high pistachio figure reflects the close antigenic relationship between the two nuts within the family, and it is why allergists typically advise cashew-allergic patients to avoid pistachios as well.⁶ The mango number is much lower, and the researchers in that study found that blanket avoidance of mango may not be warranted for every cashew-allergic child, since clinical reactions to mango were uncommon even among those who tested positive on skin-prick tests.

Why Mango Skin Can Cause a Rash

If you have ever had a blistering rash around your lips or hands after handling a mango, you have experienced mango dermatitis, and the chemistry behind it is the same chemistry that makes poison ivy so miserable. Poison ivy (Toxicodendron radicans), poison oak, and the Asian lacquer tree (T. vernicifluum) are all members of Anacardiaceae, and they produce urushiol, the oily mixture of catechol derivatives that triggers a delayed allergic skin reaction in sensitized people. Mango peel contains a related compound called resorcinol (sometimes called mangol) at much lower concentrations than the urushiol load in poison ivy sap. For most people, this amount is too little to cause trouble. But for people who have been heavily sensitized by prior poison ivy or poison oak exposure, contact with mango skin can trigger the same type of allergic response.⁷

Patch-testing studies have confirmed this cross-reactivity directly. People with known lacquer-tree contact dermatitis who test positive for urushiol also tend to react to mango-peel extracts, and vice versa.⁸ The reaction is a T-cell-mediated immune response, where the immune system recognizes the structurally similar compounds as the same threat. If you are someone who has had nasty poison ivy reactions, peeling mangoes with bare hands or rubbing the skin against your face is worth avoiding. The flesh itself is generally fine; the allergens concentrate in the peel and, to a lesser degree, in the sap that weeps from the stem end.

Urushiol and the Lacquer Tree

The Asian lacquer tree (Toxicodendron vernicifluum) offers an interesting case of Anacardiaceae chemistry being harnessed rather than avoided. For thousands of years, its refined sap has been used as lacquer across East Asia, producing a durable, lustrous coating on everything from furniture to sculpture. The very compound that causes skin reactions, urushiol, polymerizes when exposed to humidity, hardening into one of the most resilient natural finishes known. Genomic analysis of the lacquer tree has shown that the gene families involved in urushiol production are expanded compared to relatives in the family, suggesting that the trait has been under strong evolutionary selection, likely because urushiol deters herbivores and pathogens.⁹

This defensive chemistry is not limited to the Toxicodendron genus. Related irritant compounds appear across Anacardiaceae: anacardic acid in the cashew shell, alkylresorcinols in genera like Swintonia, and cardanol in marking-nut trees (Semecarpus).¹⁰ The family’s resin-duct network essentially serves as a chemical defense highway running through the entire plant. The specifics of what each genus produces vary, but the infrastructure is shared.

Marula, Jocote, and Other Edible Relatives

Beyond the big three of mango, cashew, and pistachio, Anacardiaceae contains a number of less globally famous but regionally important fruit species. The marula tree (Sclerocarya birrea) is native to sub-Saharan Africa and produces a yellow-green fruit whose pulp has a higher vitamin C content than pineapple, guava, or oranges. The fruit is eaten fresh, fermented into beer, or distilled into spirits; most people outside Africa encounter marula mainly as the flavor behind Amarula cream liqueur. The nut inside the pit is also edible and oil-rich.¹¹

In Central America, the jocote or red mombin (Spondias purpurea) fills a similar niche. It produces small, plum-like drupes that range from tart to sweet depending on the cultivar. Phylogeographic work has shown that wild populations of S. purpurea in Mesoamerica are the ancestors of the cultivated forms, and the evidence points to multiple independent domestication events rather than a single origin, a pattern that suggests the fruit was valued widely across different cultures at different times.¹² Other Spondias species include the ambarella or golden apple (S. dulcis), common in Southeast Asian and Caribbean cuisines, and the Indian hog plum (S. pinnata), which produces the largest fruit in the genus, averaging over 200 grams.¹³

Pink peppercorns, which show up in spice blends and upscale cooking, come from Schinus molle (the Peruvian pepper tree) and Schinus areira, both Anacardiaceae members native to South America. These two species have been the subject of taxonomic debate, with morphological analysis concluding they are genuinely separate species based on differences in leaflet number, size, and proportions.¹⁴ The “peppercorns” are small drupes, pink to red when ripe, with a resinous flavor that is peppery but distinct from true black pepper (which belongs to an entirely unrelated family, Piperaceae). Because Schinus is in Anacardiaceae, people with severe urushiol sensitivity occasionally report reactions to pink peppercorns, though this is uncommon.

Fruit Size and Shape Across the Family

One of the most striking things about Anacardiaceae is the sheer range in fruit size. At one end, Spondias pinnata produces drupes weighing over 200 grams with thick, juicy pulp making up more than half the fruit’s mass. At the other extreme, pistachio fruits (Pistacia khinjuk, a wild relative of the cultivated pistachio) weigh barely 2 grams, with negligible pulp.¹³ This hundred-fold difference in mass reflects different ecological strategies. Species with large, fleshy fruits evolved to attract large animals that would eat the fruit and carry the seed away from the parent tree. Species with small, dry or thin-fleshed fruits rely on smaller dispersers, or on wind and gravity.

The hard endocarp, the “pit” or “stone” inside the flesh, also varies enormously. Mango pits are fibrous, woody, and large. Cashew endocarps are thin-walled and filled with caustic liquid. Pistachio shells split neatly along a seam, a trait that breeders have selected for over millennia because it makes the nut easy to open. Despite these differences, all are variations on the same drupe blueprint: outer skin, fleshy middle layer, hard inner layer enclosing the seed.

Mangiferin and What Makes Mango Nutritionally Distinctive

Mangoes are not just another sweet tropical fruit. Their flesh and peel contain a suite of xanthone compounds, the most prominent being mangiferin, a molecule that has attracted considerable research interest. Mangiferin is a potent antioxidant and has been studied for anti-inflammatory, antimicrobial, and even anticancer properties in laboratory settings. Other xanthones found in mango include isomangiferin, homomangiferin, and mangiferin gallate.¹⁵ These compounds are not unique to mango among all plants, but their concentration in mango peel is high enough to have sparked interest in using mango byproducts as a source of natural antioxidants in the food industry.

It is worth noting that mangiferin concentrations are much higher in the peel than in the flesh, which means the part most people discard is the part richest in these bioactive compounds. In mango-producing countries, some traditional preparations make use of the peel or the immature green fruit in pickles and chutneys, inadvertently capturing more of these compounds than ripe-mango eaters typically get.

Anthracnose and the Challenge of Growing Mangoes

Growing mangoes commercially means contending with mango anthracnose disease, caused by fungi in the Colletotrichum complex. This is the most destructive disease of mangoes worldwide, capable of wiping out the entire harvest in unmanaged orchards. The disease causes dark lesions on fruit, flowers, and leaves, and it thrives in the humid tropical conditions that mangoes favor. Every commercial mango variety currently on the market is susceptible, and no cultivar has been found that resists all known strains of the pathogen.¹⁶

This is one reason the genetic diversity among wild Mangifera species matters beyond academic curiosity. If breeders can identify resistance genes in wild relatives like M. laurina or M. foetida, they could potentially breed those traits into commercial varieties. The two-group structure of cultivated mango genomes, with commercial varieties tightly clustered around Indian lines, underscores how narrow the genetic base is for the world’s most widely traded mango types.⁴ Broadening that base is an active area of research.

Sumac and the Spice Rack Contingent

Culinary sumac, made from the dried and ground berries of Rhus coriaria, is a staple of Middle Eastern and Mediterranean cooking, prized for its tart, lemony flavor. The berry clusters are harvested, dried, and ground to a deep burgundy-red powder used on grilled meats, salads, and flatbreads. Sumac is rich in polyphenolic compounds, which contribute to both its color and its antioxidant activity. Like mango and cashew, sumac is a drupe-bearing member of Anacardiaceae, though the fruits are so small and dry compared to a mango that the family resemblance is not obvious at the market.

A common source of confusion: “poison sumac” (Toxicodendron vernix) is also in Anacardiaceae but belongs to the same genus as poison ivy, not to Rhus. Culinary sumac and poison sumac are easy to tell apart. Culinary sumac grows in dry, sunny habitats and produces upright clusters of fuzzy red berries. Poison sumac grows in swamps and wetlands, with drooping clusters of smooth white berries. They are not closely related within the family, despite sharing the common name “sumac.” No one should be worried about the sumac in their spice cabinet.

A Family Defined by Chemistry

If there is a single thread connecting mangoes to cashews to poison ivy to pink peppercorns, it is the resin-duct system and the phenolic chemistry it produces. This network of interconnected ducts, branching and fusing throughout bark, leaf, and fruit, is the family’s signature innovation.² In the lacquer tree, the resins polymerize into an industrial coating. In poison ivy, they serve as a highly effective herbivore deterrent. In the mango, they contribute to the fruit’s aroma and the peel’s mild irritant properties. In the cashew shell, they protect the seed from being eaten by insects. Same basic machinery, deployed differently depending on which ecological niche each species occupies.

The family also shares this resin-duct anatomy with its closest relatives in Sapindales, the incense-tree family Burseraceae (which includes frankincense and myrrh trees) and the small family Kirkiaceae. These three families form a clade, and the resin-duct system and certain gynoecium features appear to be shared ancestral traits linking them.¹ So the mango’s closest relatives outside its own family are not other tropical fruit trees but the aromatic resin trees of desert and scrubland, a reminder that botanical families are defined by evolutionary history, not by how similar the products look to a shopper.

1
Botanical Journal of the Linnean Society. Comparative floral morphology and anatomy of Anacardiaceae and Burseraceae (Sapindales), with a special focus on gynoecium structure and evolution
2
South African Journal of Botany. Secretory ducts in Anacardiaceae revisited: Updated concepts and new findings based on histochemical evidence
3
Pesquisa Agropecuária Tropical. Genetic diversity and relationship of mango and its wild relatives (Mangifera spp.) based on morphological and molecular markers
4
PubMed Central. The genome evolution and domestication of tropical fruit mango
5
PubMed Central. Correlating the morphology of Anacardium occidentale L. fruits from 30 orchards with their physicochemical and nutritional properties
6
PubMed Central. Low percentage of clinically relevant pistachio nut and mango co-sensitisation in cashew nut sensitised children
7
PubMed Central. Mango Dermatitis After Urushiol Sensitization
8
PubMed. A study of cross-reactions between mango contact allergens and urushiol
9
PubMed Central. The chromosome-level genome for Toxicodendron vernicifluum provides crucial insights into Anacardiaceae evolution and urushiol biosynthesis
10
PubMed. A new dimeric alkylresorcinol from the stem barks of Swintonia floribunda (Anacardiaceae)
11
PubMed Central. Marula [Sclerocarya birrea (A. Rich.) Hochst.] products as a food and medicine
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PubMed Central. Domestication of a Mesoamerican cultivated fruit tree, Spondias purpurea
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Indian Forester. Fruit and Seed Morphological Characteristics of Selected Forest Tree Species of Family Anacardiaceae of Kotdwar, Uttarakhand, India
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Bonplandia. ESTUDIO TAXONOMICO-BIOMETRICO DE SCHINUS MOLLE y SCHINUS AREIRA (ANACARDIACEAE)
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Arab Journal of Chemistry. The contribution of mango fruit (Mangifera indica L.) to human nutrition and health
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PubMed Central. Mango anthracnose disease: the current situation and direction for future research