Anyone know what these are? We planted these from a spinach variety, but this year these grew in place of it. From what I've seen on Google it's apparently called Bird's Nest Fern...

We planted some spinach last year, they grew, we harvested them and died since they were out of season. But as we speak I checked the garden and these grew in place of them, Bird's Nest Fern is what they're called apparently and I'm wondering if they're edible or not since they were planted from the spinach seeds we sown last year. Thanks in advance for the help!