Common ragwort - Jacobaea vulgaris

Common Name :	Common ragwort.
Binomial Name :	Jacobaea vulgaris
Family :	Asteraceae
Photo Taken :	Ireland

Botanical Identity

Jacobaea vulgaris, commonly known as common ragwort, is a biennial or short-lived perennial plant in the Asteraceae family. It is native to Europe and parts of Asia, and has spread to other continents including North America, Australia, and New Zealand, where it is often considered invasive. It commonly grows in grasslands, roadsides, disturbed soils, and pastures, and is recognized for its bright yellow daisy-like flowers and upright growth habit.

Plant Description

Jacobaea vulgaris typically grows 30 to 100 cm tall. In its first year, it forms a low rosette of deeply lobed, ruffled leaves. In the second year, it sends up an erect, branched stem with alternate leaves that are also lobed but more divided. The stems are often tinged with purple and may be slightly hairy. It thrives in poor, dry soils and open sunlight, often colonizing grazed or disturbed areas where competition is minimal.

Flowers and Fruit Characteristics

The flowers of Jacobaea vulgaris are bright yellow with numerous narrow ray florets surrounding a dense cluster of disc florets, forming flat-topped flower heads 1.5–2.5 cm across. These appear in branched clusters from June to October. The plant produces small, dry fruits called achenes, each equipped with a pappus of fine hairs that allows wind dispersal. Its flowers are highly attractive to many pollinating insects, including bees, flies, and butterflies.

Uses and Cultural Significance

Despite its toxic alkaloids, which can harm livestock and horses if ingested in large amounts, Jacobaea vulgaris has ecological importance. It serves as a host plant for the cinnabar moth (Tyria jacobaeae), whose caterpillars feed on its leaves. Traditionally, the plant had uses in herbal medicine for treating wounds and inflammation, but internal use is discouraged due to potential liver toxicity. In conservation areas, it may be tolerated or managed carefully to balance ecological benefits with agricultural safety.

Photos of this common ragwort (Jacobaea vulgaris) were taken from the following locations:
1) July 2016: War memorial garden, Dublin, Ireland.


Written by Lonely Traveler,
For blog icflora.blogspot.com