Is it a snake?
Is it a strap?
No, it is fasciation in purple toadflax (Linaria purpurea)
I found this growing on the wall beside my garden. It is as if the stem cells (No, not that kind of stem cell!) seem to be growing in a 2D world rather than 3D. It is weaker as a result, which is why this stem is haning down.
Google fasciation for more examples.