Papaver rhoeas
A UK study of meadow flowers that focused on commercial mixes, but which also tested various common plants such as ragwort and dandelion, ranked the California poppy highly in pollen production, although it did not produce a significant amount of nectar. On a per-flower basis it ranked second, with a rate of 8.3±1.1μl. The corn poppy, "Papaver rhoeas", topped the list for per-flower pollen production with its rate of 13.3 ± 2.8μl. When measuring the entire capitulum the top two species were the ox-eye daisy, "Leucanthemum vulgare", with 15.9 ± 2μl, and "Cosmos bipinnatus", which had a rate nearly equivalent to that of the corn poppy. As poppies are not wind-pollinated, their pollen poses no allergy risk via inhalation.