Latin Name: Senecio jacobaea
Origin: Native of Europe.
Known Hazards: All parts of the plant are poisonous. The plant contains pyrrolizidine alkaloids, in isolation these substances are highly toxic to the liver and have a cumulative affect even when the whole plant is consumed.
Habitat: Waste ground and pastures on all but the poorest soils.
Edibility Rating: 0 (1-5)
Medicinal Rating: 2 (1-5)
Physical Characteristics: Biennial or short-lived perennial herb to 0.8 (rarely to 1.8) m high. Stems often branched towards apex. Basal leaves mostly 5–20 cm long and 4–6 cm wide, in a rosette, withering in flowering plants; stem leaves with upper surface dark green, underneath lighter in colour. Seeds of outer (ray) florets are hairless, those from the inner (disc) florets have fine bristles.
Flowers: Small flowers (florets) in heads mostly about 2.5 cm wide. Flowers mostly spring to autumn. The flowers are hermaphrodite (has both male and female organs) and are pollinated by Bees, flies, Lepidoptera (Moths & Butterflies). The plant is self-fertile. It is noted for attracting wildlife.
Distinguishing features: Distinguished by stem leaves deeply divided and irregularly lobed; flowerheads numerous, often in flat-topped clusters at end of stems; bracts around flowerheads 11–14 in one row, 3–6 mm long; yellow disc florets surrounded by 11–15 bright yellow petal-like ray florets 4–12 mm long; seeds 1.5–3 mm long, topped with persistent bristles 4–6 mm long.
Dispersal: Mainly by seed spread by water, on animals, in stock feed or in mud attached to vehicles. Seed may be spread by wind dispersal but mainly over short distances.
Confused With: Other Senecio species, see taxonomic texts for detailed distinguishing features.
Astringent; Diaphoretic; Diuretic; Emmenagogue; Expectorant; Homeopathy. The plant is astringent, diaphoretic, diuretic, emmenagogue and expectorant. The plant is harvested as it comes into flower and is dried for later use. Use with caution, when applied internally it can cause severe damage to the liver. See also the notes above on toxicity. An emollient poultice is made from the leaves. The juice of the plant is cooling and astringent, it is used as a wash in burns, sores, cancerous ulcers and eye inflammations. It makes a good gargle for ulcerated mouths and throats and is also said to take away the pain of a bee sting. Caution is advised here since the plant is poisonous and some people develop a rash from merely touching this plant. A decoction of the root is said to be good for treating internal bruises and wounds. A homeopathic remedy is made from the plant. It is used in the treatment of dysmenorrhoea and other female complaints, internal haemorrhages and other internal disorders.
A good green dye is obtained from the leaves, though it is not very permanent. A yellow dye is obtained from the flowers when alum is used as a mordant. Brown and orange can also be obtained.
Notes: Plants contain pyrrolizidine alkaloids, toxic to stock, that may retain some of their potency long after the pasture has been baled. Ragwort may dominate pasture and reduce carrying capacity. Plants damaged by native insects and a number of insects introduced for biological control.