Ahh I see now what you're talking about, and I agree with pushit. Maybe you bent the stem there a little bit or something to cause that? Mine are all hardened up now but I have the same thing on one of my plants that was grown outdoors last summer and I am currently doing a reveg experiment with. Rabbits decided they wanted to revoke the peace treaty between them and myself by eating all of the leaves off my girl as far up as they could reach, bending the branches badly as they pulled them down. So since then, I have collected several rabbit skins and I am using them to make a Viking costume to wear to football games... next time they'll stick to eating clover and shit.

Anyways back to the subject... that definitely isn't a calyx, strangely enough though there isn't any signs indicating that it would be male or female... maybe IT has no genitals at all? There have been lots of threads lately about identifying males/females early on, and since I have one of each showing their sex early right now, I will go take some pics now as best I can to show the clear differences in male vs female preflowers. Check back in a bit, I'll just start a new thread so everyone gets a chance to check it out.