I've been trying to find the low growing, skinny dandelion-leaved, yellow flower that pops open in the evening. About 5yrs ago I received one plant from a gardener about 20 miles away who was moving. She called them 8 o'clocks. The transplant grew that year, and for a couple weeks, at about 8:00pm EDT, in August in EDT) the flowers would pop open. Unfortunately any seeds that may have popped did not germinate (or didn't thrive) the following year. I have contacted hardyplants.com (thank you Francine) , but they no longer sell the seeds. They have something similar, so I may order some and give it a try. They have 3 -- 2 'tall' and 1 short. The reviews about this company are mixed -- hopefully any problems they've had in prior years were primarily due to user error (and hopefully I don't make the same mistake(s)).