The effects of stratification and priming on germination and emergence performance of narrow-leafed purple coneflower (Echinacea angustifolia) seeds were investigated. Seeds were pre-chilled for 3 weeks at 4 +/- 0.5 degreesC (39.2 +/- 0.9 degreesF) in light or primed for 3 days at 20 +/- 0.5 degreesC (68.0 +/- 0.9 degreesF) in darkness in Nas and Read medium (NRM) or in 2% potassium nitrate (KNO3) supplemented with 3 or 5 mum l-aminocyclopropane carboxylic acid (ACC) or 500 mg.L-1 (ppm) or 1000 mg.L-1 gibberellic acid (GA(3)). Following stratification and priming, seeds were subjected to germination and emergence tests at 25 +/- 0.5 degreesC (77.0 +/- 0.9 degreesF). Priming the seeds in NRM or KNO3 containing 3 mum ACC gave the highest germination percentages with 78% and 80%, respectively. Stratification alone increased germination to 69% compared to nontreated seeds, which had the lowest germination percentage of 57%. Emergence was enhanced by priming seeds in the presence of 3 mum ACC (75%) compared to stratified seeds (62%), while nontreated seeds had the lowest emergence percentage of 26%. These results indicate that priming in the presence of ACC might be an alternative to lengthy stratification treatments to break the dormancy and improve the germination and emergence of narrow-leafed purple coneflower seeds.