Galium, a genus of about 300 species of herbs with whorled leaves, has produced several cosmopolitan weeds, including G. aparine, which has spread to every continent except Antarctica. Cleavers? greatest economic impact is as an invasive weed. Its stems and leaves bear reverse-pointing bristles that make the plant ?clingy,? enabling it to climb up other plants and grow sprawling on top of them. The fruits, bearing hooked bristles, cling to animals? fur or humans? clothing for efficient dispersal. Some of the ?leaves? in each whorl are actually enlarged, leaflike stipules. The plant is eaten by various domestic animals, but not by humans. Grieve?s Modern Herbal reported that roasted fruits were used as a coffee substitute, and that the whole plant could be used to make a type of tea.

Cleavers is best known in traditional medicine as a diuretic or aquaretic (to increase urinary flow) for treatment of urinary disorders and edema. Other uses include treatment of insomnia and a variety of skin conditions. No scientific research has explored the validity of these uses, although traditional sources have considered the plant to be a fairly potent diuretic. It has been claimed that excessive use of topical preparations can cause dermatitis, although since the plant is used topically to treat skin inflammations, determination of causality would be difficult.

Selected References

Ehrendorfer, F. 1976. Rubiaceae. Pp. 14-36 in: T. G. Tutin et al., eds. Flora Europaea, vol. 4. Cambridge University Press, Cambridge.

Grieve, M. 1931, reprinted 1996. A modern herbal. Barnes & Noble Books, New York.

Lawson, C. A. 1976. The genus Galium (Rubiaceae) in the southeastern United States. Ph.D. Dissertation, University of Oklahoma.

Malik, N., and W. H. Vanden Born. 1988. The biology of Canadian weeds. 86. Galium aparine L. and Galium spurium L. Canad. J. Pl. Sci. 68:481-499.

Moore, R. J. 1975. The Galium aparine complex in Canada. Canad. J. Bot. 53:877-893.