Awns are needle-like structures that extend from the tips of the lemma in some grasses. Despite their apparent role in environmental adaptation and plant fitness, these structures appear to have been eliminated, for example, in rice during domestication. In this issue, Takanashi et al., (on pp. 901-918) performed quantitative trait locus (QTL) analysis and genome-wide association study (GWAS) of awn-related traits in sorghum, and identified DOMINANT AWN INHIBITOR (DAI) on chromosome 3, which encodes a negative transcriptional regulator of awn development. Further analyses suggest that neofunctionalisation of DAI occurred after duplication from its paralog (DAI^ori) on chromosome 10, and that DAI is also capable of inhibiting awn elongation in an awned rice cultivar, suggesting a conserved mechanism of awn regulation operating in the grasses.