Classification
- Kingdom: Plantae
- Clade: Angiosperms → Eudicots → Rosids
- Order: Fabales
- Family: Fabaceae (legume family)
- Genus: Galega
- Species: G. officinalis
Common names
Goat’s rue, French lilac, sweet galega, houndstongue, and in some regions “Galega”.
Description
Galega officinalis is a herbaceous perennial plant that typically attains heights of 60–150 cm (2–5 ft). It produces branching, erect stems bearing trifoliate leaves with long, narrow leaflets (10–30 mm wide) that are soft‑pubescent. The inflorescences are elongated racemes up to 30 cm long, bearing numerous pale violet to lilac pea‑type flowers each 10–12 mm across. The fruit is a slender, dehiscent pod containing several seeds. The plant exhibits a deep taproot system, enabling it to persist in a variety of soil types.
Native and introduced range
The species is native to temperate regions of Europe and western Asia, including the British Isles, the Iberian Peninsula, the Balkans, and the Caucasus. It has been widely cultivated and subsequently naturalised in North America, South America, New Zealand, Australia, and parts of Africa. In many of these locales it occurs in disturbed habitats such as roadsides, field margins, and abandoned agricultural land.
Ecology
G. officinalis grows best in full sun to partial shade and tolerates a range of soil pH from slightly acidic to neutral. It is a nitrogen‑fixing legume, forming symbiotic associations with rhizobial bacteria in root nodules, thereby enriching the soil. The flowers attract a variety of pollinators, especially bees and other insects.
Cultivation and horticulture
Cultivars have been selected for ornamental use, valued for their attractive, dangling flower spikes and extended blooming period from early summer through early autumn. The plant is moderately drought‑tolerant once established and can be propagated by seed or division of root clumps.
Traditional and medicinal uses
Historically, G. officinalis has been employed in European folk medicine as a galactagogue (to stimulate lactation), diuretic, and febrifuge. From the 19th century onward it was used in the management of diabetes mellitus; the active principle was later identified as galegine, an isoguanidine compound possessing hypoglycaemic activity. Modern pharmacological investigations have confirmed that galegine and related guanidine derivatives lower blood glucose, though their therapeutic window is narrow.
Toxicology
The plant contains several bioactive alkaloids, notably galegine, which are toxic to livestock—particularly goats and cattle—if ingested in sufficient quantities. Acute poisoning may manifest as vomiting, diarrhoea, tremors, and, in severe cases, cardiac arrhythmia. Consequently, G. officinalis is listed as a poisonous plant in many agricultural references.
Phytochemistry
Key constituents include:
- Galegine (isoguanidine): primary hypoglycaemic agent.
- Coumarins (e.g., scopoletin).
- Flavonoids such as quercetin derivatives.
- Saponins and various polysaccharides.
Regulatory status
Due to its toxicity, certain jurisdictions restrict the use of G. officinalis extracts in dietary supplements. In the United States, the plant is not approved as a pharmaceutical agent, and products containing galegine are subject to FDA oversight.
Conservation
The species is classified as “Least Concern” by the International Union for Conservation of Nature (IUCN) owing to its extensive distribution and abundant populations throughout its range. It is not subject to significant threats in its native habitats.
Historical notes
Records of G. officinalis cultivation date to medieval monastic gardens in Europe, where it was prized for both ornamental and medicinal properties. It was introduced to the United States in the early 19th century and rapidly naturalised in the Midwest and Northeast.
References
- Kew Gardens, “Plants of the World Online,” Galega officinalis.
- Flora Europaea, Volume 5, Fabaceae.
- R. R. Kahn et al., “Galegine and its derivatives: pharmacological effects and toxicology,” Journal of Ethnopharmacology, 2020.
- USDA NRCS Plant Database, Galega officinalis.
This entry reflects current, peer‑reviewed scientific and horticultural literature as of 2026.