Groundsel (Senecio vulgaris)

Groundsel (Senecio vulgaris)

Kingdom: Plantae 
Division: Magnoliophyta 
Class: Magnoliopsida 
Order: Asterales 
Family: Asteraceae 
Genus: Senecio 
Species: Senecio vulgaris
Synonyms; Grundy Swallow, Ground Glutton, Simson, Sention.

The name Groundsel is of old origin, being derived from the Anglo-Saxon groundeswelge, meaning literally, ‘ground swallower,’ referring to the rapid way the weed spreads. In Scotland and the north of England it is still in some localities called Grundy Swallow – only a slight corruption of the old form of the word – and is also there called Ground Glutton. In Norfolk it is often called Simson or Sention, which has by some been considered an abbreviation of ‘Ascension Plant.’ It seems more probable that ‘Sention’ is a corruption of the Latin, Senecio, derived from Senex (an old man), in reference to its downy head of seeds; ‘the flower of this herb hath white hair and when the wind bloweth it away, then it appeareth like a bald-headed man.’

Groundsel (Senecio vulgaris) is a cosmopolitan (world-wide) annual weed of cultivation in the family Asteraceae. It is rarely found away from gardens or other areas of regularly disturbed ground. Extremely variable in all its parts, the deeply toothed leaves and slightly fleshy stems topped with rayless, yellow flower heads (capitula) and fluffy white seed heads are very familiar to gardeners everywhere. This plant can grow from seed to seeding in only a few weeks and do so in all types of soils, damp or dry.

The genus Senecio, belonging to the large family Compositae, includes about 900 species, which are spread over all parts of the globe, but are found in greatest profusion in temperate regions. Nine are natives of this country. The essential character of the genus is an involucre (the enveloping outer leaves of the composite heads of flowers) consisting of a single series of scales of equal length. The florets of the flower-heads are either all tubular, or more commonly, the central tubular and the marginal strap-shaped. The prevailing colour of the flowers in this genus is yellow purple (white or blue being comparatively rare).

A very common weed throughout Europe and Russian Asia, not extending to the tropics. It is abundant in Britain, being found up to the height of 1,600 feet in Northumberland. It grows almost everywhere, and is to be found as frequently on the tops of walls as among all kinds of rubbish and waste ground, but especially in gardens. Groundsel is one of those plants which follows civilized man wherever he settles, for there is hardly a European colony in the world in which it does not spring up upon the newly tilled land, the seeds probably having mingled with the grain which the European takes with him to the foreign country. Other home weeds, such as the thistle, have made their way across the seas in the same manner.

Similar species – Woodland Groundsel – Senecio sylvaticus. A variety of Senecio vulgaris, named S. radiata (Koch), with minute rays to the outer florets, is found in the Channel Islands.

Growing to a height of 10-40cm (4-16in), a winter annual (sometimes biennial) weed of cultivated soil and disturbed ground. Leaves are arranged along the round or slightly angular stem, erect, stem in a spiral and are deeply lobed with toothed margins, lower ones stalked, upper ones clasping the stem, and may be smooth to hairy or wooly. Stems are hollow and succulent, often branching at the top and are frequently purple in colour. It is juicy, not woody, and generally smooth, though sometimes bears a little loose, cottony wool. The root consisting of numerous white fibres.

The leaves are oblong, wider and clasping at the base, a dull, deep green colour, much cut into (pinnatifid), with irregular, blunt-toothed or jagged lobes, not unlike the shape of oak leaves. Plants have a very variable habit and leaf shape. The level of variability depends on the amount of soil disturbance. In a frequently disturbed soil more genotypes are recorded, in a less disturbed habitat the population is more stable. Some plants have ligulate ray florets and hybrids occur with Oxford ragwort, S. squalidus. It is essentially an inbreeding species and ecotypes have developed with tolerance to saline conditions and to acid rain. Races of groundsel have developed with resistance to one or more herbicide groups.

Open clusters of self fertile small yellow cylindrical rayless flower heads 5-12mm (0.25-0.5in) long with black-tipped bracts, are in close terminal clusters or corymbs, the florets yellow and all tubular; the scales surrounding the head and forming the involucre are narrow and black-tipped, with a few small scales at their base. And can be found almost all year although March to April is the main blooming time. The flowers are usually self-fertilised.

The flowers are succeeded by downy heads of seeds. Seeds are thin and ridged, about 12mm (0.5in) long and tipped with a tuft of silky white hairs, each seed being crowned by little tufts of hairs, by means of which they are freely dispersed by the winds. Groundsel flowers and sets seed throughout the year. An individual plant may continue to flower and set seed for several months. The main period of flowering is April to October and most seed is set from May to October. Flower stems cut in bud do not ripen viable seed but seed from plants cut in flower had germination levels of 35%. Groundsel produces around 1,200 seeds per plant.

Most seeds can germinate at once and seedlings emerge within a few days of seed shedding. Freshly shed seed of groundsel generally requires light but not stratification for germination. However, it has been noted that seed produced in spring is somewhat more dormant than seed produced in summer or autumn. Seed germinates better at lower (10-15 °C) rather than higher (20-30 °C) temperatures. Seeds buried for 6 months in soil under natural conditions germinate readily on exposure to light. Seed germination is increased by a period of dry storage.

Seedling emergence generally occurs from February to December with the main peak from June to October or in May and September. Flushes of emergence are probably related to rainfall events that follow soil cultivation. Germination and establishment is better in conditions of high humidity. Seedlings are frost tolerant but little germination occurs in winter until the temperature begins to rise. Groundsel can complete its life-cycle in 5-6 weeks but may take longer on nutrient-rich soils. In sand, sandy loam and peat soils, field seedlings emerged from the top 30-40 mm of soil with up to 80% emerging from the surface 5 mm.

Groundsel can complete its life cycle in 5-6 weeks. The cycle may take longer in richer soils.

Persistence and Spread: In studies in cultivated soil, 85% of seeds had germinated within 1 year and 100% within 5 years. In undisturbed soil, groundsel seed had declined by 87% after 6 years. Losses were due to germination and to seed death in equal amounts. Seed buried deeper in soil persists longer than seed in the upper layers of soil.

The seeds have a pappus of hairs and are widely dispersed by the wind. Laboratory tests suggest maximum seed dispersal distances of 1.9 and 2.9 metres at wind speeds of 10.9 and 16.4 km/hour respectively but this would be affected by plant height. The pappus also aids dispersal by adhering to clothes and to animal fur.

Groundsel seed was a contaminant of cereal and vegetable seeds, but not of grass and clover.

Groundsel can be a problem if found with forage crops because it is toxic to livestock. It contains several pyrrolizidine alkaloids, which can cause progressive and irreversible liver damage, these alkaloids are also found in Common Ragwort, but Ragwort also contains other more poisonous alkaloids. A lethal dose of Groundsel is about 5-8% of the animals body weight. Sheep and goats have rumen bacteria that neutralise the alkaloids, so they are able to consume larger amounts of Groundsel, so grazing by sheep is sometimes used as a control.

Feeding and other inter-species relationships

Groundsel is used as a food plant by some Lepidoptera species including the Flame Shoulder moth. Larvae of the Cinnabar Moth – Tyria jacobaeae, an insect that feeds on Common Ragwort, also eat Groundsel. Research is also being done with a rust fungus, Puccinia lagenophorae to control Groundsel. Groundsel acts as a host for Cinerarea leaf rust and the fungus that causes black root rot in peas. It can also carry seed transmitted virus diseases that attack crop species.

Groundsel seed has been found in the droppings of sparrows, and seedlings have been raised from the excreta of various birds. Seed has also been found in cow manure.

Feeding and other inter-species relationships Associated with Senecio vulgaris:

is parasitised by conidial anamorph Golovinomyces cichoracearum var. fischeri – Groundsel Mildew (Erysiphales: Erysiphaceae) Ing, B., 1990 Ellis, M.B. & J.P., 1997is parasitised by cleistothecium Golovinomyces cichoracearum var. fischeri – Groundsel Mildew (Erysiphales: Erysiphaceae) Ing, B., 1990 Ellis, M.B. & J.P., 1997is parasitised by uredium Coleosporium tussilaginis – a rust fungus (Uredinales: Coleosporiaceae) Ellis, M.B. & J.P., 1997is parasitised by subepidermal telium Coleosporium tussilaginis – a rust fungus (Uredinales: Coleosporiaceae) Ellis, M.B. & J.P., 1997is parasitised by telium Puccinia lagenophorae – a rust fungus (Uredinales: Pucciniaceae) Ellis, M.B. & J.P., 1997live stem is parasitised by grouped aecium Puccinia lagenophorae – a rust fungus (Uredinales: Pucciniaceae) Ellis, M.B. & J.P., 1997live leaf is parasitised by grouped aecium Puccinia lagenophorae – a rust fungus (Uredinales: Pucciniaceae) Ellis, M.B. & J.P., 1997live leaf is parasitised by Bremia lactucae – a downy mildew (Peronosporales: Peronosporaceae) Ellis, M.B. & J.P., 1997
capitulum may contain larva Ensina sonchi – a gall fly (Diptera: Tephritidae) White, I.M., 1988capitulum may contain larva Sphenella marginata – a gall fly (Diptera: Tephritidae) White, I.M., 1988capitulum may contain larva Trupanea stellata – a gall fly (Diptera: Tephritidae) White, I.M., 1988
leaf is mined by larva Trypeta artemisiae – a gall fly (Diptera: Tephritidae) White, I.M., 1988leaf is mined by larva Trypeta immaculata – a gall fly (Diptera: Tephritidae) White, I.M., 1988leaf is mined by larva Trypeta zoe – a gall fly (Diptera: Tephritidae) White, I.M., 1988leaf is grazed by larva Longitarsus gracilis – a flea beetle (Coleoptera: Chrysomelidae) Bullock, J.A., 1992leaf is grazed by imago Longitarsus gracilis – a flea beetle (Coleoptera: Chrysomelidae) Bullock, J.A., 1992

Feeding and other inter-species relationships Associated with Senecio sylvaticus:

is parasitised by Golovinomyces cichoracearum var. fischeri – Groundsel Mildew (Erysiphales: Erysiphaceae) Ing, B., 1990is parasitised by uredium Coleosporium tussilaginis – a rust fungus (Uredinales: Coleosporiaceae) Ellis, M.B. & J.P., 1997is parasitised by subepidermal telium Coleosporium tussilaginis – a rust fungus (Uredinales: Coleosporiaceae) Ellis, M.B. & J.P., 1997
capitulum may contain larva Sphenella marginata – a gall fly (Diptera: Tephritidae) White, I.M., 1988

Feeding and other inter-species relationships Associated with Senecio cambrensis: Welsh groundsel

is parasitised by telium Puccinia lagenophorae – a rust fungus (Uredinales: Pucciniaceae) Ellis, M.B. & J.P., 1997live leaf is parasitised by grouped aecium Puccinia lagenophorae – a rust fungus (Uredinales: Pucciniaceae) Ellis, M.B. & J.P., 1997live stem is parasitised by grouped aecium Puccinia lagenophorae – a rust fungus (Uredinales: Pucciniaceae) Ellis, M.B. & J.P., 1997

Feeding and other inter-species relationships Associated with Senecio viscosus:

is parasitised by conidial anamorph Golovinomyces cichoracearum var. fischeri – Groundsel Mildew (Erysiphales: Erysiphaceae) Ing, B., 1990 Ellis, M.B. & J.P., 1997is parasitised by cleistothecium Golovinomyces cichoracearum var. fischeri – Groundsel Mildew (Erysiphales: Erysiphaceae) Ing, B., 1990 Ellis, M.B. & J.P., 1997is parasitised by uredium Coleosporium tussilaginis – a rust fungus (Uredinales: Coleosporiaceae) Ellis, M.B. & J.P., 1997is parasitised by subepidermal telium Coleosporium tussilaginis – a rust fungus (Uredinales: Coleosporiaceae) Ellis, M.B. & J.P., 1997
capitulum may contain larva Sphenella marginata – a gall fly (Diptera: Tephritidae) White, I.M., 1988
live leaf is spotted by mostly hypophyllous colony of Ramularia anamorph Ramularia senecionis – an anamorphic fungus (Mycosphaerellales: Mycosphaerellaceae) Ellis, M.B. & J.P., 1997 [causes round or angular, yellowish or pale brown spots 2-10mm diam.]

According to Linnaeus, goats and swine eat this common plant freely, cows being not partial to it and horses and sheep declining to touch it, but not only are caged birds fond of it, but its leaves and seeds afford food for many of our wild species. Groundsel, in common with many other common garden weeds, such as Chickweed, Dandelion, Bindweed, Plantain, etc., may be freely given to rabbits. It is said that Groundsel will at times entice a rabbit to eat when all other food has been refused. Rabbit-keeping is a very practical way of reducing the butcher’s bill, and no means of feeding the rabbits economically should be neglected. Stores of both Groundsel and Chickweed might well be dried in the summer for giving to the rabbits in winter time with their hay.

The plant has diuretic properties and has been used medicinally in the past. Consumption of large quantities by stock animals can cause liver damage. The alkaloids responsible are not destroyed by drying or by fermentation in silage.

Management: Groundsel may be controlled by cultivation with the hand or tractor-hoe. Stubble cleaning is effective in dealing with shed groundsel seeds. The surface soil should be cultivated to a depth of 50 mm and the operation repeated at 14-day intervals. The area around manure heaps, where the weed often occurs in abundance, should be kept clean to prevent groundsel seed contaminating the manure.

Seed numbers in soil may be reduced by around 70% after fallowing for 1 year. Seed numbers are reduced to a lesser extent under cropping with winter wheat. Crop competition reduces seed production by shading out the weed. Regular fallowing every 5th year over a 15-year period stabilised seed numbers at a low level provided that the groundsel was not allowed to grow uncontrolled during the intervening cropped years.

Groundsel seedlings with 2-6 leaves are tolerant of flame weeding but the seeds are susceptible to soil solarization.

Biological control control of groundsel with the naturalised rust fungus Puccinia lagenophorae, Cooke. has been the subject of much research. The fungus now occurs widely in the UK and may cause considerable damage to groundsel plants but there is no guarantee of an attack by the pathogen. Also different lines of the weed vary in susceptibility to the fungus. Caterpillars of the cinnabar moth Tyria jacobaeae feed on groundsel in June-July and may weaken or even kill a plant before it can set seed. The caterpillars themselves are attacked by several different predator insects that can have a drastic effect on their numbers and hence effectiveness.

Anglo-Saxons reputedly prized Groundsel for its medicinal properties, mainly as a herb used in poultices, it is also said to cure stagger in horses. Latin derivation – Senecio from senex “old man” from the gray hairs on the seeds, and vulgare/vulgaris meaning common. Common name derivation – from the Anglo-Saxon “grondeswyle” meaning “ground glutton”, referring to it’s propensity to spread quickly.

Groundsel, so well known as a troublesome weed, is connected in the minds of most of us with caged birds, and probably few people are aware that it has any other use except as a favourite food for the canary. And yet in former days, Groundsel was a popular herbal remedy, is still employed in some country districts, and still forms an item in the stock of the modern herbalist, though it is not given a place in the British Pharmacopoeia.

The whole herb is used, collected in May, when the leaves are in the best condition and dried. The fresh plant is also used for the expression of the juice. 
Chemically, Groundsel contains senecin and seniocine. The juice is slightly acrid, but emollient.
Diaphoretic, antiscorbutic, purgative, diuretic, anthelmintic. 

It was formerly much used for poultices and reckoned good for sickness of the stomach. A weak infusion of the plant is now sometimes given as a simple and easy purgative, and a strong infusion as an emetic: it causes no irritation or pain, removes bilious trouble and is a great cooler, or as Culpepper puts it: 
‘This herb is Venus’s mistress piece and is as gallant and universal a medicine for all diseases coming of heat, in what part of the body soever they be, as the sun shines upon: it is very safe and friendly to the body of man, yet causes vomiting if the stomach be afflicted, if not, purging. It doth it with more gentleness than can be expected: it is moist and something cold withal, thereby causing expulsion and repressing the heat caused by the motion of the internal parts in purges and vomits. The herb preserved in a syrup, in a distilled water, or in an ointment, is a remedy in all hot diseases, and will do it: first, safely; secondly, speedily.’

‘The decoction of the herb, saith Dioscorides, made with wine and drunk helpeth the pains in the stomach proceeding from choler (bile). The juice thereof taken in drink, or the decoction of it in ale gently performeth the same. It is good against the jaundice and falling sickness (epilepsy), and taken in wine expelleth the gravel from the reins and kindeys. It also helpeth the sciatica, colic, and pains of the belly. The people in Lincolnshire use this externally against pains and swelling, and as they affirm with great success. The juice of the herb, or as Dioscorides saith, the leaves and flowers, with some Frankinsense in powder, used in wounds of the body, nerves or sinews, help to heal them. The distilled water of the herb performeth well all the aforesaid cures, but especially for inflammation or watering of the eye, by reason of rheum into them.’

Gerard says that ‘the down of the flower mixed with vinegar’ will also prove a good dressing for wounds, and recommends that when the juice is boiled in ale for the purpose of a purge, a little honey and vinegar be added, and that the efficacy is improved by the further addition of ‘a few roots of Assarbace.’ He states also that ‘it helpeth the King’s Evil, and the leaves stamped and strained into milk and drunk helpeth the red gums and frets in children.’

Another old herbalist tells us that the fresh roots smelled when first taken out of the ground are an immediate cure for many forms of headache. But the root must not be dug up with a tool that has any iron in its composition.

Some of the old authorities claimed that Groundsel was especially good for such wounds as had been caused by being struck by iron.

Groundsel in an old-fashioned remedy for chapped hands. If boiling water be poured on the fresh plant, the liquid forms a pleasant swab for the skin and will remove roughness.

For gout, it was recommended to ‘pound it with lard, lay it to the feet and it will alleviate the disorder.’

A poultice of the leaves, applied to the pit of the stomach, is said to cause the same emetic effect as a dose of the strong infusion. A poultice made with salt is said to ‘disperse knots and kernels in the flesh.’

In this country, farriers give Groundsel to horses as a cure for bot-worms, and in Germany it is said to be employed as a popular vermifuge for children.

A drachm of the juice is sufficient to take, internally.


Species composition of hedgerows and verges have an infinite variety where not only are no 2 the same, but they are different every 100 yards or sometimes every few yards.