This seedling opened its maiden bloom yesterday. The tag says: Southern Hospitality 4Y-R x mini 7Y-Y seedling. And so offers an explanation to my quandary about where the doubled seedling came from. Most likely, in gathering and planting seeds I switched the tags somehow. This seedling is probably from (Garden News x viridiflorus seedling) and the two siblings (double and jonquil-type) are from (Southern Hospitality x mini jonquil seedling).