What is in the same family as barley?

December 6, 2025 •

3 min read

Over 10,000 species of true grasses belong to the extensive Poaceae family, which is the exact same plant family as barley. This places barley in a massive botanical group alongside many of the world's most important cereal grains, from wheat and oats to maize and rice.

Quick Summary

Barley belongs to the Poaceae family, commonly known as the grass family, which includes major cereal grains such as wheat, rye, maize, rice, and oats. This botanical classification links numerous economically and agriculturally important plants through a shared lineage.

Key Points

Botanical Family: Barley belongs to the Poaceae family, commonly known as the grass family.
Close Relatives: Within the same tribe (Triticeae), barley's closest relatives are wheat (Triticum) and rye (Secale).
Other Cereal Kin: Other major cereals in the wider Poaceae family include maize (corn), rice, oats, and sorghum.
Shared Traits: As members of the Poaceae family, these plants share features like spikelets and hollow stems, a result of their shared ancestry.
Vast Diversity: The Poaceae family is one of the largest plant families, encompassing not just cereals but also bamboos and various pasture grasses.
Evolutionary Importance: Genetic studies confirm the close relationships within the Triticeae tribe and the broader Poaceae family, influencing modern crop breeding.
Wild Ancestor: The wild progenitor of barley, Hordeum spontaneum, is still found in the wild and is closely related to the cultivated variety.

The Poaceae Family: An Overview

Barley's place in the plant kingdom is within the Poaceae family, one of the largest and most economically significant plant families worldwide. Known colloquially as the true grass family, Poaceae includes not only cereal crops but also bamboos, pasture grasses, and lawn varieties. The family's ubiquity and diversity are key reasons behind its crucial role in global ecosystems and human civilization. Members of this family share specific physical traits, such as hollow stems (called culms) plugged at nodes, and narrow, alternate leaves with parallel veins. The reproductive parts are typically tiny, plain-colored flowers clustered into spikelets. It is estimated that grasslands dominated by Poaceae cover approximately 40.5% of the Earth's land area, excluding polar regions.

Close Relatives within the Tribe Triticeae

While barley shares its family with a vast array of grasses, its closest relatives belong to the same tribe, Triticeae. Within this tribe, barley (genus Hordeum) has a very tight relationship with several other well-known cereal grains:

Wheat: The genus Triticum, which includes all varieties of wheat (e.g., bread wheat, durum), is a primary relative. Both barley and wheat were among the first crops domesticated by humans in the Fertile Crescent region.
Rye: Belonging to the genus Secale, rye is another member of the Triticeae tribe and is closely related to both barley and wheat. Like barley, it is used for a variety of food products and alcoholic beverages.

This close botanical kinship explains why these cereals often share similar morphological and genetic traits, as well as why they contain gluten proteins.

Other Notable Poaceae Relatives

Moving beyond the immediate tribe, the Poaceae family includes many other staples and important plants that are related to barley in the broader sense:

Maize (Corn): A major global cereal crop, maize belongs to the subfamily Panicoideae, making it part of the same family as barley, but a more distant relative.
Rice: This staple for billions is in the subfamily Ehrhartoideae and is also a member of the Poaceae family.
Oats: An important cereal used for human food and animal feed, oats belong to the subfamily Pooideae, the same subfamily as barley, but a different tribe (Aveneae).
Sorghum and Millets: These grain crops are also part of the expansive Poaceae family, showcasing its incredible diversity.
Bamboo: The woody grasses known as bamboo are in the Bambusoideae subfamily, also a member of the Poaceae family.

Barley, Wheat, and Rye: A Comparison


Feature	Barley (Hordeum vulgare)	Wheat (Triticum aestivum)	Rye (Secale cereale)
Family	Poaceae	Poaceae	Poaceae
Tribe	Triticeae	Triticeae	Triticeae
Common Use	Brewing, animal feed, soups, stews	Bread, pasta, cereals, baked goods	Flour for bread, whiskey, animal fodder
Gluten Content	Contains gluten (hordeins)	Contains gluten (glutenins, gliadins)	Contains gluten
Nutritional Profile	Rich in fiber, particularly beta-glucan; lower protein than wheat	Higher protein content; significant fiber lost in milling unless whole grain	Similar nutritional profile to wheat, high in fiber

The Role of Wild Relatives

Barley's wild progenitor, Hordeum spontaneum, shares a direct lineage with cultivated barley (Hordeum vulgare) and is considered part of its primary gene pool. Studying these wild relatives helps scientists understand the genetic diversity that allows barley to adapt to different environments and develop resistance to pathogens. The ability of cultivated barley to interbreed with its wild ancestor highlights the very close genetic relationship that has been maintained since its domestication. Less closely related but still useful for genetic studies are species like bulbous barley (Hordeum bulbosum), which belongs to the secondary gene pool. This broader genetic resource holds valuable traits that breeders can use to improve modern crops.

Conclusion

In conclusion, barley is a member of the vast and economically vital grass family, Poaceae. This places it alongside a multitude of essential plants, including its closest relatives within the tribe Triticeae—wheat and rye. The Poaceae family also encompasses many other significant cereal crops, such as maize, rice, and oats, highlighting a shared botanical heritage for some of the world's most important foods. From the grains we use for brewing and baking to the grasses that feed livestock and fill our lawns, barley's family is a pervasive and fundamental part of our agricultural and natural world. For further insights into the Poaceae family's importance, refer to the National Institutes of Health article on the relationships of cereal crops.

Frequently Asked Questions

Barley (Hordeum vulgare) belongs to the Poaceae family, also known as the grass family.

Yes, both wheat and rice are in the same plant family, Poaceae, as barley. Wheat is a very close relative within the same tribe, Triticeae, while rice is a more distant relative within a different subfamily.

Yes, corn (Zea mays), like barley, is a member of the extensive Poaceae (grass) family. However, it is in a different subfamily (Panicoideae) than barley (Pooideae).

The scientific name for cultivated barley is Hordeum vulgare, placing it in the genus Hordeum.

No, not all plants in the Poaceae family contain gluten. While wheat, rye, and barley all contain different types of gluten, other Poaceae members like rice, maize, and millet do not.

Yes, bamboos are related to barley. They are both part of the Poaceae (grass) family, though they belong to different subfamilies.

The main differences between barley and wheat include their nutritional content and primary uses. While both are in the same family and tribe, barley is richer in fiber (especially beta-glucan) and primarily used for animal feed and brewing, whereas wheat has higher protein and is mostly used for flour and baked goods.