I have a sprout plant that had three cotyledons, thei has happened before and the pants do not usually thrive but this one is huge but otherwise looks normal. Will it produce sprounts?
I actually had some beans last year and they produced four seedlings with three cotyledons and then all the subsequent sets of leaves were also in threes.
Its not uncommon but plants that come like that tend to struggle i think you will find that the other plant that bore only two will grow about five times faster
I think it's probably a mutation, unless it's due to damage to the seed. This year I've got a pea with no chlorophyll, so its ghost white. Obviously that one won't thrive!