Skeletonleaf Bursage (Franseria discolor Nutt.)
Skeletonleaf bursage is a small, herbaceous perennial in the aster (Asteraceae) family. Though native to the region, it is considered noxious due to its aggressive growth and ability to spread rapidly. Plants typically grow up to 1–2 feet tall, producing branched stems that range from silver-green to light brown. The leaves are alternately arranged and deeply lobed (pinnately or bipinnately). The upper leaf surface is greenish-gray and may be smooth to slightly hairy, while the lower surface is white and covered with short, dense hairs. Skeletonleaf bursage blooms from early to late summer. The flowers are small, yellow, and relatively inconspicuous. The plant is monoecious, meaning it produces both male and female flowers. Male flowers form in spike-like clusters at the top of the plant, while female flowers develop in small clusters along the upper leaf axils. This species spreads aggressively through an extensive rhizomatous (creeping) root system, allowing it to form dense colonies. Seeds are produced in small burs equipped with up to 10 spines, which can be green to brown in color and aid in dispersal. Its persistent root system and seed production make Skeletonleaf bursage difficult to control once established.
Quick ID Guide
Height:
• 1–2 feet tall
• Upright, branched stems (silver-green to light brown)
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Leaves:
• Alternate arrangement
• Deeply lobed (pinnate to bipinnate)
• Upper surface: greenish-gray, smooth to slightly hairy
• Lower surface: white with dense, short hairs
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Flowers (Early–Late Summer):
• Small, yellow, inconspicuous
• Monoecious (separate male & female flowers on the same plant)
• Male flowers: spike-like clusters at stem tips
• Female flowers: small clusters in upper leaf axils
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Fruit/Seed:
• Small burs with up to 10 spines
• Green turning brown
• Spines aid in animal dispersal
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Roots:
• Aggressive rhizomatous (creeping) root system
• Forms dense colonies
Management Options
​Prevention and sound cultural practices should be used whenever possible to limit the establishment and spread.
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Since skeletonleaf bursage is native to North America, there are currently no approved biological control agents available.
Hand pulling or digging is generally not recommended unless the entire root system can be completely removed. Any remaining rhizome fragments are capable of resprouting. Mowing is not an effective control method for this species.
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For larger infestations, herbicide applications can provide control. Treatments applied in spring or fall are recommended, although applications made during the bolting stage may also be effective. Always read and follow the herbicide label before application.
Contact TCWP for guidance on proper product selection, rates, and application methods. Contact Sublette County Weed & Pest for assistance with product selection, rates, and application timing.
