Cooper's rubberweed is not considered an edible plant. Historical records indicate only that the roots or their resinous latex were occasionally chewed as gum by Native Americans. No reliable records suggest that the roots were swallowed in meaningful quantities or that the leaves, flowers, or seeds were eaten as food. The roots contain woody fibres and bitter resins that make them unpleasant to chew. Unlike genuine natural chewing gums, the roots gradually splinter into coarse fibres rather than forming a smooth elastic mass. Any slight starchy sweetness is quickly overwhelmed by resinous bitterness and a persistent latex-like flavour. No preparation method has been shown to improve the flavor or remove the toxic compounds present within the plant. Consequently, modern consumption cannot be recommended [2-3]. Edibility Rating: 0.5/5. Cooper's rubberweed receives an edibility rating of 0.5 out of 5. While the roots have a documented history of being chewed as gum, the plant possesses no meaningful food value and contains compounds capable of poisoning livestock. The unpleasant flavor, woody texture, and safety concerns make it unsuitable for human consumption. Taste and Culinary Qualities: Fresh roots initially appear more promising than they ultimately prove to be. Young roots are firm yet slightly flexible and produce a modest amount of resin when chewed. Their texture initially suggests that a gum-like material may develop. Instead, chewing causes the woody tissues to splinter into numerous irritating fibers. Rather than becoming smooth and elastic, the fibers separate into coarse strands that remain in the mouth and require repeated removal. The flavor is equally disappointing. Bitter resins dominate from the first few moments of chewing, accompanied by a distinctly latex-like quality. A faint starchy sweetness can occasionally be detected beneath the bitterness, but it never develops sufficiently to improve the experience. Older roots become increasingly woody and even less suitable for chewing. The leaves, stems, and flowers are regarded as inedible and have not traditionally been consumed [2-3]. Traditional Uses: Ethnobotanical records indicate that several Native American groups occasionally chewed the roots or collected their resinous exudates as a form of natural chewing gum. This appears to have been a minor use rather than an important cultural practice. Unlike many other edible native plants, Cooper's rubberweed was never gathered as a staple food, and there are no records of the roots being cooked, dried into flour or incorporated into other foods. Its traditional use demonstrates the ingenuity of Indigenous peoples in utilizing available natural resources, but it does not indicate that the species is safe or desirable for regular consumption [2-3]. Harvesting: Historically, roots would have been collected whenever plants were actively growing, most likely during spring or summer when soils remained soft enough for excavation. Young plants provide the best roots because their tissues remain less woody than those of mature specimens. The deep taproot requires careful digging to avoid breakage. Once lifted, the smaller lateral roots are easier to chew than the thick central root. Given the toxicity of the species, harvesting is not recommended except for botanical or ethnobotanical study [2-3]. Seasonality (Phenology): New foliage emerges during spring following seasonal rainfall. Flowering generally occurs from midsummer into early autumn, producing bright yellow flower heads during one of the driest periods of the year. Seeds mature during late summer and autumn. Roots remain present throughout the year and allow the plant to survive prolonged drought. During winter, the above-ground portions often die back while the taproot remains dormant until favorable moisture returns. Nutritional Value: No reliable nutritional analyses have been published for Cooper's rubberweed. Given its toxicity and lack of historical use as a food, nutritional evaluation has received little attention. The plant should not be considered a source of calories or nutrients. Hazards: Cooper's rubberweed contains toxic sesquiterpene lactones, particularly hymenoxon and hymenovin, compounds responsible for poisoning sheep and other grazing livestock. Consumption can lead to a condition known as spewing sickness, characterized by digestive disturbance, weakness, weight loss and persistent vomiting. The symptoms resemble poisoning caused by death camas. Although humans would normally consume far smaller quantities than grazing animals, the presence of these toxins makes regular consumption inadvisable. The roots should not be swallowed after chewing. Livestock managers generally regard dense populations of rubberweed as undesirable pasture plants. Pregnant or breastfeeding women, children and individuals with liver disorders should avoid all internal use [2-3]..

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.


Although several members of the genus have been used medicinally by Indigenous peoples, Cooper's rubberweed is much better known for its toxicity than for any medicinal applications. Traditional chewing of the roots appears to have been more related to obtaining resin than to therapeutic treatment. Because the plant contains biologically active sesquiterpene lactones, self-medication should be avoided.

Cooper's rubberweed is well suited to xeriscapes and native plant gardens. Cooper's rubberweed is an attractive and ecologically valuable native perennial that has adapted remarkably well to some of the driest landscapes of the American Southwest. Its long flowering season supports native pollinators, and its drought tolerance makes it an excellent candidate for native restoration and water-wise landscaping. Wildlife Value: Despite its toxicity to grazing mammals, Cooper's rubberweed provides valuable nectar and pollen for numerous native insects. Bees, butterflies and various pollinating flies regularly visit the bright yellow flower heads. The plant also contributes to soil stabilisation through its deep taproot. Most large herbivores avoid grazing it because of its bitter chemistry.

Special Uses