Glycine is a genus of flowering plants in the legume family Fabaceae, order Fabales, comprising approximately 28 accepted species. The genus is best known for the cultivated soybean, Glycine max, which is among the world's most economically important crop plants and the primary global source of plant protein and vegetable oil.
The genus is divided into two subgenera. Subgenus Soja contains the cultivated soybean (G. max) and its wild progenitor, the wild soybean (G. soja), both annual plants native to East Asia. Subgenus Glycine encompasses at least 25 wild perennial species, the majority of which are endemic to Australia, with a few species such as G. tomentella and G. tabacina ranging from Australia to East Asia.
Glycine species are climbing or trailing herbaceous legumes. Like other legumes, many species host symbiotic nitrogen-fixing bacteria (Rhizobia) in root nodules, allowing them to enrich soil fertility. The foliage of several species serves as larval food for moth species including the engrailed, nutmeg, and turnip moths.
Beyond its wild Australian species, the genus has an outsized global footprint through Glycine max. The soybean was domesticated in north-central China between 6,000 and 9,000 years ago and is now the most widely grown legume on Earth, with Brazil and the United States leading global production. Its seeds, rich in both protein (38–45%) and oil (~20%), are processed into foods including tofu, soy milk, soy sauce, edamame, and tempeh, as well as animal feed and industrial products.
Etymology
The genus name Glycine was introduced by Carl Linnaeus in 1753 and is derived from the Greek glykys (γλυκύς), meaning "sweet." Linnaeus applied the name because one of the species he originally included in the genus, Glycine apios (now Apios americana), bears sweet, edible roots that were used as food by Native Americans. Following a 1966 discovery that Linnaeus's designated type species belonged to the genus Pueraria, the conserved name became Glycine Willd., based on G. clandestina — a consequence being that the original rationale for the sweet-root name no longer applies, as none of the current species have the edible roots that inspired it.
Distribution
The great majority of Glycine species are endemic to Australia, where they occur as wild perennials across diverse habitats. A small number of species, including G. tomentella and G. tabacina, extend their range from Australia into East Asia. The cultivated soybean (G. max) and its wild progenitor (G. soja) are native to East Asia (China, Japan, Korea, and Russia) and are now grown globally as major agricultural crops.
Ecology
Glycine species are legumes capable of fixing atmospheric nitrogen through a symbiotic relationship with soil bacteria of the Rhizobia group. This nitrogen-fixing ability makes them valuable in crop rotations and for soil improvement. The foliage of soybean (G. max) is known to serve as a food source for the larvae of several moth species, including the engrailed (Ectropis crepuscularia), nutmeg moth (Hadena confusa), and turnip moth (Agrotis segetum).
History
The soybean (Glycine max) has one of the longest agricultural histories of any crop plant. Genomic evidence supports a single domestication event from wild G. soja in north-central China between 6,000 and 9,000 years ago. Soybeans reached Japan by around 5,000–3,000 BC and Korea by 1,000 BC. They were introduced to Java around the 13th century, and European traders brought soybean products to the Indian Subcontinent by the 17th century. The crop arrived in the Americas and Europe from China during the 18th century. The genus itself was formally described by Linnaeus in 1753, though its taxonomic circumscription was substantially revised in 1978 when the conserved name Glycine Willd. replaced Glycine L. following clarification of the type species.
Cultural Uses
Glycine max (soybean) is one of humanity's most versatile food crops. Traditional unfermented products include edamame, soy milk, tofu, and tofu skin. Fermented preparations include soy sauce, miso, nattō, tempeh, and fermented bean paste. Soybean oil is widely used in cooking and in industrial applications. Defatted soybean meal is a primary source of protein in animal feed globally, and textured vegetable protein derived from soy is used extensively in meat and dairy substitutes. Soybeans are a complete protein source and are especially significant in vegetarian and vegan diets.
Taxonomy Notes
The taxonomy of Glycine has a complex history. Carl Linnaeus established the genus in 1753 with eight species, none of which remain in the genus today — all have since been transferred to other genera including Apios, Pueraria, Amphicarpaea, and others. In 1966, Bernard Verdcourt demonstrated that the type species of Linnaeus's genus (G. javanica) belonged to Pueraria. Verdcourt proposed re-anchoring the genus on Glycine clandestina Willd. (1802), a resolution formally adopted in 1978. As a result, Glycine L. is a rejected name and Glycine Willd. is the conserved name. The genus is divided into two subgenera: subgenus Soja (annual species, East Asian) and subgenus Glycine (perennial wild species, predominantly Australian). As of February 2025, Plants of the World Online accepted 28 species.
