Where several female flowers develop in a leaf axil, clusters of burs develop. Inside the bur are two compartments that each potentially contain a seed. At Lubbock, Texas, a population density of seven to 12 stems per square foot produced 380 to 460 burs per square foot. In germination tests, seeds that remained encapsulated within the bur did not germinate regardless of exposure to a range of constant or alternating temperatures. Sixteen percent germination occurred when unsplit burs were exposed to concentrated sulfuric acid for 60 minutes and constant 70 F temperature for 21 days.
Seed contributes to the spread of woollyleaf bursage and likely is a source of new infestations.