Silphium radula var. gracile, Slender rosinweed

Rosinweed is a prairie native herbaceous perennial in the aster family found in central USA and parts of Canada. It has a high coefficient of conservatism (9 out of 10), which means that its presence in the wild is an indication of high-quality prairie. It is especially valuable for pollinators like native bees. As she reported at the LNPS meeting in February, UL graduate student Kimberly Hamm documented 24 different native bee species on the rosinweed plants in her test plots, the highest by far among the 15 native plant species in her study. She also documented 300 bee visits during her observation window, followed by beebalm (200), and much less for the other 13 plant species in her plot.

Rosinweed's sunflower-like blooms have just begun and will continue through summer. It sets seed all summer. Seed is easy to collect and grow! It is adaptable to most soil types and loves full sun and can tolerate wet and dry conditions, even last summer's drought. Growing from a taproot and short rhizomes, it will form clumps but does not aggressively spread.  

Photo credits: Sally and Andy Wasowski, Larry Allain