Cleavers

Galium aparine L.

Family: Rubiaceae.

Names:

Cleavers

Other names:

Bedstraw
Burrweed
Catchweed Bedstraw
Goosegrass
Small Goosegrass
Stickywilly
Sweethearts

Summary:

The mature plant has a distinctive sticky feeling and rings of 6-8 leaves on the prostrate or scrambling and climbing, square stems with curved spines on the angles. The leaves have backward directed tiny spines on the edges and midrib on the underside. On the upper surface there are curved spines. The fruit is a pair of globular fruitlets covered with hooked spines on a straight stalk and is produced from small, white 4 petalled flowers in spring.

Description:

Cotyledons:

Two. Oval to egg shaped. Blade 7 to 15 mm long. Tip indented with a distinctive apical notch. Edges smooth. Base tapered to squarish. Surface hairless. Petiole shorter than blade and 4-5 mm long. The seedling has a long hypocotyl and a long epicotyl.

First leaves:

Develop in a ring around the stem (whorl) with initially 4 then 5-6 leaves to a whorl. Leaves club shaped. Tip pointed. Edges smooth and bristly. Base tapered. Surface somewhat warty. [Some authors suggest 5-6 leaves for the first whorl of Cleavers (Galium aparine) and 4-5 leaves for the first whorl of Three-horned Bedstraw (Galium tricornutum)].

Leaves:

Later whorls have 6 to 8 leaves.
Stipules - Whorled.
Petiole - Absent.
Blade - Lance to club shaped, 10-60 mm long with a fine point, 1.5 mm long, formed by the midrib extending beyond the tip. On the upper surface they carry stout hooked hairs. The edges are often rolled backwards. The edges and midrib on the underside have backwardly directed spines similar to those on the stem. Mid stem leaves are the longest, lower leaves are very narrow.
The whole plant has a distinctive sticky feeling.

Stems:

In the early stages stems are semi-erect and become straggling, weak, twining and prostrate, much branched especially from the base, up to 1500 mm or more, square in cross section with ridges on the corners, hollow and stout. They carry stout downward directed curved spines on the corners of the stem.

Flower head:

Axillary or terminal cyme. Stalk (peduncle) is longer than the leaves and carries 1-5 flowers on short, 2-4 mm long, straight stalks (pedicels) that are almost at right angles to each other.

Flowers:

Small and white 4 petalled flowers.
Bracts - At the base of the peduncle.
Ovary -
Sepals -
Petals - 4, white, 1 mm long with pointed tips.
Stamens -
Anthers -

Fruit:

2 globular to kidney shaped fruitlets, 3-4 mm long on a straight stalk that is longer than the fruit. They are covered in spiny, hooked hairs that are thickened towards the base and have a sticky feeling. They adhere readily to clothing or animals.

Seeds:

Up to 1000 brown to grey seeds which are round, 1-3 mm in diameter and with the surface covered with hooks are produced on each plant (Cermakova, 1988). Tip rounded. Surface covered in short hooked spines. Base indented

Roots:

Key Characters:

Whorls of 6-8 leaves, Stout stems. Fruit kidney shaped and bristly with hooked hairs.

Biology:

Life cycle:

Annual. Germination occurs mainly in Autumn.
Seeds need vernalisation. The moisture regime and amount of light were unimportant for the timing of flowering. Nutrition had some influence on the timing of flowering, but day length and maximum temperature were the most important factors in this respect. A formula developed from the product of day length and the effective max. temp. (0C above the base temp. of 5.30C) enabled relevant developmental rates of arable field populations of Galium aparine to be predicted over a broad range of environmental conditions. The flowering date in the field could be correctly predicted for cohorts of plants emerging at different dates at 2 sites (Weide and Van der Weide, 1992).

Physiology:

The cuticle has an amorphous wax which makes penetration by most herbicides more difficult (Bravais et al., 1993).

Reproduction:

Flowering times:

Spring in western NSW.
Spring in WA.

Seed Biology and Germination:

Ensiling or passage through the intestinal tract does not affect germination of seeds (Cermakova, 1988).
Freshly harvested seeds are in a state of primary dormancy. They then enter a period of secondary dormancy that diminishes in spring. The seeds were able to germinate at 200C in light and to a lesser extent in the dark. Alternating between 10 and 200C did not seem to promote germination (Kazinczi and Beres, 1995).
Herbicide applications later than normal but before peak flowering were most effective at reducing seed production (Andersson, 1994).
(Froud-Williams and Ferris-Kaan, 1991) has some data on seed dormancy.
Seed bank is probably exhausted in 3-4 years in UK (Wilson and Lawson, 1992).
Seed can not be effectively removed from rape with screens or a trieur (Rawa et al., 1990).
Seed has a high annual rate of decrease (about 80% per year) and for which seedling emergence represented an av. of 15% of the annual seed bank (Barralis et al., 1988).
Seeds died after 2-4 weeks in cattle manure (Schokker, 1988).
It has an extended germination period (Kees, 1988).

Vegetative Propagules:

Hybrids:

Allelopathy:

Seed extracts inhibited the germination and growth of Digitaria sanguinalis and Medicago sativa seedlings but it did not inhibit Trifolium repens. The extracts also inhibited germination of G. aparine itself.
Lettuce placed together with G. aparine seed had inhibited germination and growth (Komai et al., 1986).

Population Dynamics and Dispersal:

COMPETITION
Densities of 100/m2 reduced rape yield by 65% and increase lodging to 35% in Poland (Rola and Rola, 1992).
More competitive under hi N conditions in spring wheat (Lintell-Smith et al., 1992).
More competitive than sterile brome and less competitive than field poppy (Lintell-Smith et al., 1991).
Main competitive effect is to reduce 1000-grain wt in wheat (Wright and Wilson, 1992).
Had no effect on 1000-seed wt in Russia (Roder et al., 1990).
5 times more competitive than wild oats. For Galium aparine the economic threshold was as low as 2 plants/m2, Avena sterilis 7 and 12/m2, Lolium multiflorum 25 - 35/m2, Bromus sterilis 40/m2, Vicia sativa 5 -10/m2 under high N conditions in winter wheat in Italy (Zanin et al., 1993). Not competitive under low N conditions in winter wheat in Italy (Zanin et al., 1993) or the UK (Lintell-Smith et al., 1991) or Germany (Springer and Heitefuss, 1988a) (Springer and Heitefuss, 1988b) especially if no water stress (Baylis et al., 1992). Yield decline due to one G. aparine plant/m2 was 0.24% in winter barley and 0.14% in winter wheat in Russia (Roder et al., 1990).
Minimum threshold level for cleavers was 0.2 plants/m2 in rape in Germany (Munzel et al., 1991). Control resulted in 12-14% increases in 1000 grain wt and up to 25 dt/ha grain yield in winter wheat in Germany (Hofmann and Pallutt, 1989). No crop yield advantage from removal of G. aparine prior to GS 32 in winter wheat in UK. Damage thresholds for G. aparine and V. arvensis were 80 plants/m2 in wheat in the USSR (Zubkov, 1987).With a full nutrient supply, cleavers were more competitive than wheat (Rooney et al., 1990). A decision model supporting weed control in cereals based on economic thresholds including cleavers is available for Germany (Gerowitt, 1990). 0.1-0.5 plants/m2 threshold for winter cereals in Germany (27). 38-fold av. increase in winter wheat over a 2-year period in Italy (Catizone and Viggiani, 1990). Control of >2 weeds/m2 gave higher yields in winter wheat in Germany (Springer and Heitefuss, 1988b). 1 plant/m2 reduced yields on loess soils by 0.020 and 0.011% in spring barley in Germany (Roder et al., 1987). G. aparine competition reduced the number of ears and the number and wt of grain/ear and the 1000-grain weight in wheat in Poland (Rola and Rola, 1987). Wheat at high plant density suppressed late-germinating G. aparine in Germany (Kees and Reinert, 1989). Losses varied from 0.7 to 2.9% per plant/m2 in wheat in the UK (Wilson and Wright, 1987). 96-100 plants/m2 decreased yields of rape from 2.6 to 0.9 t/ha in Poland (Rola et al., 1987). More competitive than chickweed and mayweed in winter oilseed rape in Britain (Bowerman et al., 1994).
Increasing wheat seeding rate reduced biomass and seed numbers of cleavers (Mennan and Zandstra, 2005).
TILLAGE
Increased with tillage in Canadian crop rotations (Dessaint et al., 1993). More common under minimum tillage than ploughing in the UK (McCloskey et al., 1991). G. aparine densities built up most rapidly with no-tillage, followed by shallow tine cultivation, and least rapidly with ploughing. ioxynil + bromoxynil + mecoprop in Jan, followed by fluroxypyr in April reduced seed banks by 60%/yr. A population model for G. aparine showed that almost complete control (97-99%) would be needed to prevent populations from increasing (Wilson and Wright, 1991). Germination and establishment could be markedly reduced by cultivation between 1 h after sunset and midnight in Germany (Hartmann and Nezadal, 1990). Population increased 5 times more rapidly with shallow cultivation systems than with ploughing. 7.8, 9.3 and 0.4% produced plants after shallow tine cultivation, no tillage and ploughing, respectively (Wilson and Froud-Williams, 1988).
NUTRITION
More weed seed was produced under Hi N conditions in winter wheat and less seed produced at higher wheat densities (Wright, 1993). Increased N fertilisation promoted Galium aparine (Claupein and Baeumer, 1992). 0.4-9.9 plants/m2 reduced yields of winter oilseed rape by 5% in UK (Lutman et al., 1993). Threshold levels for the weed in rape and winter wheat were approx. 0 and 0.1 cleavers plants/m2 respectively in Germany (Petzoldt and Muhling, 1989). Wild oats (Avena fatua) were more competitive than cleavers in wheat in the UK (Wilson and Wright, 1990). Galium aparine in gaps of a winter wheat crop produced up to three times more DM compared to gap-free conditions (Niemann, 1990). Cleavers outgrew the crop on plots receiving high N (Franz et al., 1990).
ECOLOGY
Abundance increased after fire in Utah USA (Cousens et al., 1987).
Mean rate of migration in forest was >2 m/yr which was one of the highest rates in North America (Matlack, 1994).
Shade tolerant species (MarAnon and Bartolome, 1993).
Requires 325-340 degree days to get to 2 leaf stage (Riba-Pijuan et al., 1991).
Low-red:far-red light ratio under the plant cover prevented germination (Zweep et al., 1990).
Increases after annual chemical treatment stops in a Bavarian study (Otte, 1990).
Harvesters tended to spread seed from clumps of the weed over a wide area (Petzoldt and Muhling, 1989).
Population modelling to describe G. aparine populations, the parameters required and their predictive value (Weide et al., 1990).
Weed species with a high population growth rate, infestation was determined mainly by seed production, plant survival and rate of emergence. For those with a low growth rate, seed survival in soil was critical (Zwerger and Hurle, 1989).
Cleavers increased in a winter Wheat/Bean rotation in Germany (Zwerger et al., 1990).
The root system of cleavers was shallower than wheat but was often of greater total length (Rooney et al., 1990).
Galium aparine were the main weeds in the inorganic crops; these weeds were only present at very low levels in some of the organic fields in the UK (Samuel and Guest, 1990).
46.6% of the seed was shed onto the soil surface while 42.0% appeared with the harvested seed in wheat and rape in Germany (Petzoldt and Muhling, 1989).

Origin and History:

Europe. Asia.

Distribution:

ACT, NSW, SA, TAS, VIC, WA.
Cleavers are found in most parts of Tasmania.
Introduced to WA in 1996 as a contaminant of Canola from New Zealand.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate.

Soil:

Occurs equally over podzolic, brown, rendzina and chernozem soil types in Poland (Fijalkowski et al., 1990). Grows better on heavier soil types (Tottman et al., 1988).

Plant Associations:

Significance:

Third most important weed of wheat in Hungary (Toth et al., 1989).
Fourth most common weed in winter wheat and barley fields in the UK (Whitehead and Wright, 1989).

Beneficial:

It is used in traditional medicine in China (Li et al., 1994), Australia (McKeon, 1994), India (Das, 1994), and Portugal for its diuretic and spasmolytic properties (Seabra et al., 1993).

Detrimental:

It is predominantly a weed of waste land and gardens, but occurs occasionally in crops. In Europe it is a major weed of crops and it is capable of being strongly competitive. Its climbing habit allows it to overwhelm crops and cause lodging, while the mature stems impede harvesting.
Rarely eaten by stock because the four sharp toothed edges on the stems injure the mouth.
Weed of dry land crops associated with Vicia sativa and Avena fatua in China (Qiang et al., 1994).
Weed of cereals in Denmark (Mathiassen and Kudsk, 1992), dry-land cereals in Spain (Riba Pijuan et al., 1991), flax in Romania (Cseresnyes et al., 1987), forage mallow (Bojas, 1990), peppermint in Montana (Carda et al., 1992), strawberries in Ireland (MacGiolla-Ri et al., 1989), sugar beet in Poland(Powlowski, 1991), wheat in Poland (Hochol, 1990) and China (Berghaus and Retzlaff, 1989), white clover (Bojas, 1990), root crops in Poland (Honchol, 1990)
Weed in Pakistan (Ghafoor and Shad, 1990)
Common weed of clover (Trifolium spp.), winter wheat, spring barley, potatoes, winter wheat and oats in Czechoslovakia (Borovickova, 1992).
Common garden weed in the UK (Copson and Roberts, 1991).
Host for Mycocentrospora acerina, a disease of carrots in Norway (Hermansen, 1992).
Small pieces of cleavers stems and leaves impaired the efficiency of the straw walkers and sieves (Petzoldt and Muhling, 1989).
Carries a Powdery mildew (Paul and Kaul, 1987).
Contaminates grain and impedes harvest of cereals (Roder et al., 1986).

Toxicity:

Addition of up to 3% G. aparine seeds to diets did not affect duck performance, whereas 0.3% supplement of weed seeds negatively affected growth and health condition of broiler chickens (Musielak, 1991).
Contaminated feed reduced growth in cockerels (Mazurkiewicz et al., 1991).
Obstruction of the gizzard occurs in fowls through selective picking up of seed from contaminated grain (Prigli, 1990).
0.68% cleavers in chicken feed caused 0.42% deaths and 10.06% showing symptoms of poisoning. Treat with Biolent Forte at 1 mL per bird. Post-mortem examination showed that the seeds had caused gastric obstruction and intestinal atony (Januszewski et al., 1988).
Both plant and seed contain saponins, hesperidin, quinolinic acid, glucosides and coumarin (Cermakova, 1988).
Mixed feed with 0.75% Catchweed, resulted in high mortality of chickens 5 days old. In the gizzard of week-old chickens there were up to 29 Catchweed seeds, and in 2 week-old chickens there were up to 72 Catchweed seeds (Cermakova, 1988).
Turkey chicks were not affected by 3% in feed (Koncicki et al., 1989).

Legislation:

Noxious weed of WA.

Management and Control:

See Control of Cleavers with Herbicides

Thresholds:

Probably around 1-2 plants/m2.

Eradication strategies:

Ryegrass and Kikuyu pastures
Graze pasture continuously from the break of the season to keep it less than 5 cm tall. Apply 6 L/ha in May/June when Cleavers are less than 10 cm long. Grazing 7 days after spraying may improve control. This treatment will adversely affect Clover production.

Herbicide resistance:

The cuticle has an amorphous wax which makes penetration by most herbicides more difficult (Bravais et al., 1993).
Triazine resistant populations are in France (Pichot, 1991).
Tolerates some phenoxy herbicides (Ghafoor and Shad, 1990).

Biological Control:

Related plants:

Slender Bedstraw (Galium divaricatum)
Small Bedstraw (Galium murale)
Three horned Bedstraw (Galium tricornutum) has curved fruiting pedicels (stalks) and no hairs on the fruit or upper surface of the leaves.
(Galium spurium)

Plants of similar appearance:

Field Madder (Sherardia arvensis). Cleavers can be distinguished from Field Madder by the shape of the cotyledon in the young stage, and in more advanced plants by the size of the leaves and the number in a whorl, and the colour of the flowers. Cleavers have hairs on the edges of the leaves that point backwards (away from the leaf tip) whereas Field Madder has hairs that point forward.
Slender Myoporum (Myoporum caprarioides Benth.) is a native plant.
(Burrill, 1992) has colour photos and identification tips.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P218. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P800.

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P339.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P620. Photo.

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P210. Photo.

Hyde-Wyatt, B.H. and Morris, D.I. (1975). Tasmanian weed handbook. (Tasmanian Department of Agriculture, Hobart, Tasmania). P61. Diagrams.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #571.1.

Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P115. Diagrams. Photos.

Figures in brackets, for example (Wilson and Lawson, 1992), refer to the main reference database. Contact HerbiGuide for more information.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.