Like Dave, I have a bunch of this in my yard. Probably among the first ( all very old) cultivars that I bought in the mid nineties from a now defunct Daylily farm in Northern Vermont.
This year, HP started blooming July 10 and ended August 1, making it a ML plant in my yard. The plants are not uniform, some are taller, some are shorter. They do throw more polys than any other flower in my yard. They are very pretty, with a delicate old fashioned form and nice color and eye. Extremely hardy, I've never done anything extra for them, yet all the clumps continue to thrive close to thirty years later.