they are probably seed pods Did they flower?
You could collect the seed if you want. but they wont grow into the same variety next year.
I dont think the remaining radishes will be too palatable either. I find they go woody.

Yeah they did flower! I planted them in the garden, but the soil must have been too shallow, as nothing grew underneath! lol I'm a late newcomer to gardening, and I was just experimenting! Thankyou for your time! I will do a lot more reading next time!

You need to pull up and eat your radishes before they flower, Jacquie otherwise, as Seaburngirl says, they'll be too old and woody, and you won't be able to get your teeth into them!! Usually, if you notice them flowering, it's too late to use them at all! Annie