Salicaceae – Willow Family

Fast growing, deciduous woody plants, members of the Salicaceae can adapt to a variety of soil conditions, saturated roots, and easily rebound from disturbance or floods. Various types of Salix (willow) appear in Willamette Valley Wetland Prairies as multi-stalked shrubs rather than the “Weeping Willow” form many Americans are familiar with. In the Pacific Northwest, Populus (Poplars or Cottonwoods) are true trees, but not common to Wetland Prairies. Rather they are a prevalent component to many riparian woodlands. The stems, branches, and roots of the Salicaceae contain two hormones frequently used in plant propagation as well as making the ubiquitous medicine cabinet pain remedy, Aspirin. The earliest recorded medicinal use of willow dates back to 400 BC when Hippocrates advised patients to chew on the bark to reduce fever and inflammation.[1]

Indolebutyric acid (IBA) stimulates root growth and is found in high concentrations in the meristems of many Salicaceae species.[2] The hormone Salicylic acid is present in Salix bark and involved in signaling a plant’s defense mechanisms to ward off pathogens. Once the plant’s internal defenses are triggered (by a wound in the bark, insect chewing, or broken limbs) an attack on one part of the organism induces a resistance response to pathogens in other parts of the plant by converting the salicylic acid into a volatile chemical form.[3] One of the biggest threats to newly propagated cuttings is infection by bacteria and fungi. Salicylic acid helps plants to fight off infection, and can increase survival rates in propagules or damaged trees. When occupying dynamic environments such as an annually flooded wetland or unstable river banks, these two chemicals combined increase Salicaceae fitness by increasing adaptability in regularly shifting ecosystems.

It is also possible to utilize these chemical properties for producing healthy, fast growing propagules at home. Many horticulturists brew “Willow Water,” which contains active amounts of both Salicylic acid and IBA leached into the solution. Salicylic acid helps fight off infection and gives vulnerable cuttings increased survival rates while IBA stimulates root growth.[4]

 

 

 

 

[1] University of Maryland Medical Center: <http://www.umm.edu/health/medical/altmed/herb/willow-bark&gt;

[2] Simpson, M. Plant Systematics 2^nd ed. Academic Press, Burlington, MA.

[3] Foster S, Duke JA. A Field Guide to Medicinal Plants and Herbs of the Eastern and Central US. Boston, MA: Houghton Mifflin; 2000: 321-323.

[4] Hoffmann D. Therapeutic Herbalism. Santa Cruz, CA: Therapeutic Herbalism Press; 2000.