There's a tiny hollow in the top. I find that soaking them overnight helps them to grow.

If in doubt plant them on their side. The growing point is normally the sharper side. Much more obvious if as said they have been soaked overnight.

Got that wrong, didn't I, Ob - except for the soaking bit!

To be honest it does not matter if you plant them upside down, they will still grow.

LOL. That's OK, then! I did wonder why, having planted them upside down (probably!) that they still grew and flowered.