Thanks, Sue! Your experiment provides enough motivation to believe the article, and now I take it as established that: "oxidation of the germination inhibitor(s) present in the pericarp by H2O2 promotes seed germination".
For that variety of Zinnia, and your variety(s) of day-lilies.
It makes sense to me that each variety should tweak its dormancy behavior a little. That seems like an effective strategy for a variety, to arrange for seeds to last varying numbers of years in the ground, and then to sprout in a variety of circumstances, hopefully sometimes emerging when competition is low but opportunities are high.
