Heirloom tomatoes odd flowers

Hi i'm growing a number of varieties of toms.
Red berry
Ailsa craig
yellow pigmy
Gardners delight

Pink Brandywine
Black Russian

I've notice on my black russians that the flower trusses have a single flower that is bigger than all the other flowers on the trusses.  This flower is more like a dandelion flower than a tom.  All flowers are generally bigger but what is this odd single folower born on a much thicker stem :?:

Are these varieties (Black Russian/Pink Brandywine) flowers sexed unlike other toms :?:

I got it with marmalade but didn`t get it in Big boy last year ,just assumed it was an odd batch.

which brandywines are you growing noshed?  I grew yellow last year, but they were certainly weird!!!!  I thought I had blight or something nasty as the bottoms on all the fruits were brown and/or split.  Anywayz, Oliver told me that it is natural in the brandywines, and his owner has grown the pink ones too.  She has some yellow ones this year as I sent her some seeds.

I'm not growing them this year as I already have 19 different varieties!!!  But apart from the weird look, they were lovely, very 'meaty' tomatoes and nice flavour