Galium aparine L. cleavers,
Also called clivers, goosegrass, kisses, stickyweed, stickybud, sticky willy
This species is a straggling climber, growing up to 3 m long, with slender 4-angled stems. Its narrow leaves can reach 7 cm long and are arranged in groups (whorls) of 6-8 (rarely 4) around the stem.
This is a scrambling annual whose stems may reach up to five feet in hedgerows, fields and gardens where it flourishes. It clings by the curved hook-like prickles on the four angles of the stems and the edges of the leaves.
Indeed the whole plant is covered in minute hooked hairs, and can cling to skin, fur and clothing. It has been raised from the excreta of various birds demonstrating that it is consumed by them. Viable seeds have also been found in manure and compost showing that they are resistant to the heat required to decompose manure and compost and that they are persistent. The flowers are tiny (2mm across), white, 4-petalled tubes. The fruits are purplish green covered with numerous colourless joked bristles, often borne in clusters of two or three. The individual fruits are approximately 2mm to 2.5 mm across and weighs approximately 0.02 to 0.05 grams. Germination mostly occurs in autumn but may occur in spring. In harsh winters it is the latter that survives. The germination in different seasons is a characteristic that has enabled this plant to proliferate.
These fruits are also covered in hooked hairs which catch in the fur of passing animals or the peoples clothing. This is an efficient distribution mechanism that has contributed to the plant’s wide geographical range.
.It is well known by children for its ‘stickiness’, owing to its covering of hooked hairs. There is a rather cruel Scottish children’s game involving this plant. The trick is to persuade somebody to allow a piece of it to be put in their mouth – then pull it out fast. The hooks being rather sharp, the game is called ‘bleedy tongues’! Galium aparine is also well known by herbalists for its medicinal properties.
Geography and distribution
Galium aparine is naturally widespread throughout Europe, North America and some parts of Asia, and occurs as far north as Alaska and Greenland. Its seeds have been recorded from deposits of Paleolithic or Mesolithic Age, which render it less probable that it owes its presence to conditions created by man, despite being especially associated with habitat conditions that are partially artificial. It can grow at heights of up to 1500 feet above sea level. It has been introduced as far south as Australia, New Zealand, and the sub-Antarctic Islands. It can be a prolific weed of cereal crops (especially in Europe and North America). Heavy infestation can cause significant yield losses, and its seeds can be difficult to separate mechanically from those of crops such as oilseed rape (canola). It is found throughout the British Isles (except in some places in the far north) and appears to be increasing in abundance in recent years despite the use of species-specific agricultural herbicides. Galium aparine can be found growing naturally on scree slopes and shingle banks.
Used as a love medicine by one tribe, the infusion of plant was used as a bath by women to be successful in love. Also used as a hair tonic, said to be good for the hair, making it grow long. Several Native American Tribes used an infusion of the plant for gonorrhea. A red dye is obtained from a decoction of the root, it is said to dye bones red. It was also believed to remove freckels. Gerard writes of Clivers as a marvelous remedy for the bites of snakes, spiders and all venomous creatures. A thick matt of the stems, when used as a sieve for filtering milk, was said to give healing properties to the milk
John Ruskin went so far as to trace out aesthetic and moral standards for flowers labelling weeds as unfinished. He argued that it was unnatural for a plant to have a cluster of bristles springing from its centre. Interestingly the term weedy when applied to humans has connotations of weakness or feebleness rather that those of strength and intimidation characteristics of many weed species.
This is not a recommendation merely information
The whole plant is edible, though not particularly tasty, and in China, for example, it is eaten as a vegetable. In times of war of famine it has been eaten possibly from desperation rather than as a delicacy. Its seeds can be roasted to prepare a sort of coffee substitute. It is also reputed to have a number of medicinal properties, having been used in traditional medicine (usually as an infusion) to treat kidney problems, skin disorders and high blood pressure among other ailments. Archaeological evidence suggests that it may have been used in this way for hundreds, if not thousands, of years. Cleavers is still used by medical herbalists today, although scientific evidence regarding its effectiveness is still lacking.
Britain’s wild harvest
Kew’s Sustainable Uses of Plants Group undertook a survey of commercial uses of wild and traditionally managed plants in England and Scotland for the Countryside Agency, English Nature and Scottish Natural Heritage to determine the economic role of wild plants and to assist in their sustainable use. Despite the revival of interest in herbal remedies in UK most plant material used in herbal products is imported. However, there are exceptions. In Norfolk, for example, cleavers is gathered from hedgerows and used in herbal products.
Millennium Seed Bank: Seed storage
Kew’s Millennium Seed Bank Partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.
This weedy species is an annual that can be grown in temperate regions, in parts of the garden managed for wildlife, as either a summer or winter annual (or occasionally as a biennial). The seed is thought to be viable for around 2-6 years unless frozen. Seeds should be sown in moist soil, preferably a rich loam, with above-average fertility and pH of 5.5-8.0. Seeds must be buried to germinate, ideally at a depth of 2-10 mm. Seeds that have passed through the gut of a herbivore are thought to have a higher germination rate. Development is rapid with flowers appearing as soon as eight weeks after germination. Ripe seeds develop from summer through to autumn, depending on the region in which plants are grown. Supports such as pea sticks can be provided, as this plant likes to scramble. Plants will die down after the fruits are released at which point seeds must be collected for next year’s plants.
Note that this plant can be invasive. In some parts of the world it is a serious weed of crops and native vegetation, where it can out-compete indigenous species. For this reason, if cultivating cleavers, care should be taken to prevent its spread into farmland or sensitive areas of conservation importance.
Climbing mechanism of Galium aparine.
Galium aparine is a herbaceous climbing plant that attaches to host plants mainly via its leaves, which are covered by hooked trichomes. Although such hooks are found on both leaf surfaces, the leaves of G. aparine are mainly positioned upon the leaves of supporting plants and rarely beneath. In order to understand the mechanism underlying this observation, we have studied structural and mechanical properties of single leaf hooks, frictional properties of leaf surfaces, turgor pressure in different leaf tissues and bending properties of the leaves in different directions. Abaxial and adaxial leaf hooks differ significantly in orientation, distribution, structure and mechanical properties. In accordance with these differences, friction properties of leaves depend on the direction of the applied force and differ significantly between both leaf surfaces. This results in a ratchet mechanism. Abaxial leaf hooks provide strong attachment upon the leaves of adjacent plants, whereas adaxial hooks cause a gliding-off from the underside of the leaves of host plants. Thus, the leaves of G. aparine can function as attachment organs, and simultaneously orient themselves advantageously for their photosynthetic function. Further adaptations in turgor pressure or concerning an anisotropy of the flexural stiffness of the leaves have not been found.
Always on the bright side: the climbing mechanism of Galium aparine
Georg Bauer,1 Marie-Christin Klein,2,3 Stanislav N. Gorb,2,3 Thomas Speck,1 Dagmar Voigt,2,3 and Friederike Gallenmüller1,*
Author information ► Article notes ► Copyright and License information ►
This article has been cited by other articles in PMC.
References and credits
Allen, D.E. & Hatfield, G. (2004). Medicinal Plants in Folk Tradition: an Ethnobotany of Britain and Ireland. Timber Press, Portland.
Bown, D. (2008). The Royal Horticultural Society Encyclopedia of Herbs and their Uses. Dorling Kindersley, London.
Gucker, C. (2005). Galium aparine. Fire Effects Information System [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available online
Milliken, W. & Bridgewater, S. (2004). Flora Celtica –Plants and People in Scotland. Birlinn, Edinburgh.
Prendergast, H.D.V. & Sanderson, H. (2004). Britain’s Wild Harvest: The Commercial Uses of Wild Plants and Fungi. Royal Botanic Gardens, Kew and The Countryside Agency, London.
Preston, C.D., Pearman, D.A. & Dines, T.A. (eds) (2002). New Atlas of the British and Irish Flora: an Atlas of the Vascular Plants of Britain, Ireland, the Isle of Man and the Channel Islands. Oxford University Press, Oxford.
Kew Science Editor: William Milliken
Kew contributors: Steve Davis (Sustainable Uses Group)
Copyediting: Emma Tredwell
While every effort has been taken to ensure that the information contained in these pages is reliable and complete, the notes on hazards, edibility and suchlike included here are recorded information and do not constitute recommendations. No responsibility will be taken for readers’ own actions.
Richard Mabey 2010 Weeds Profile books London
Edward Salisbury 1961 Weeds and Aliens Collins Press London