Rhinanthus minor Yellow Rattle or Hay Rattle average 400 seeds per gram. Yellow flowers, the name comes from the ripe seeds rattling in the seed capsules. Hemiparasite it lives of minerals and water from the roots of other plants, helps to establish plants in a wildflower meadow. Beast sown Autumn to break seed dormancy, sowing early spring seed requires stratification. Habitat grassland. Annual Hgt 12 - 50cm Flowers May to August.