Grindelia is a perennial member of the sunflower family that is specific
to western North America and some parts of South America. The hardiness
of the plant is expressed in its species name of “robusta,” while
several common names, such as tar weed and gum weed, speak to the high
resin content in the plant, which can exceed 20% in concentration.
In the era of the Eclectic Physicians, grindelia was a popular herbal to
counter cough associated with asthma and bronchial cough. Due to
potential toxicity, however, the anti-inflammatory compounds in the
leaves and flowers are largely delivered homeopathically today. Applied
topically as a poultice or skin wash, these compounds help to reduce
discomfort from poison ivy and other minor skin irritations.