Cardiocrinum seed have a low germination rate. It is said that less than half of what looks like good seed is really not viable at all. Although they are related to Lilium, you can't backlight the seed to see if they contain embryos. (I've tried.) At any rate, they are very erratic germinators in my experience. I've grow Cardiocrinum cordatum. In the late spring after the seeds have experienced their first winter, I think I got about 1% sprouting. Then for three more years, I'd get another 5-10% each year. Sometimes they would put up a second leaf that was no bigger than the original initial cotyledon, but mostly no second leaf at all. I had attributed that to my lack of care, but maybe not? Unfortunately, in my cold climate they were never hardy enough to survive the winters, although the ungerminated seeds had not problem.