Can Any One Tell Me What This Fish Is Please

I thought it was a five banded barb and I think it came with some of them but as its grown it has a rounder shape and less bands plus it keeps away form the others
It's quite small, maybe 6 cm and it must be somehting like 6-8 months old
It's quite peaceful swimming slowly around the tank usually among the plants. It only speeds up when the food is about.
Sorry the pics are not that good. And please ignore the Gourami that snuck into one.
It's quite a pale colour but that maybe as it is on its own, I think if it coloured up it would be reddish

Yes it is definately a black widow

I'd never have gone for a tetra. Now I know thanks.

A little tip-off for you: tetra fish have a short fin, called an adipose fin, between their dorsal fin and their tail fin.  If you're ever unsure of a fish's identity, looking to see if they have one of those, can help narrow it down into whether they might be a tetra of some sort or not. 

I can confirm Sues suspicions on the identity of the dracena, and her advice is correct!

Did it come with a little label, out of interest? Does the aquarium shop sell gardening items or reptiles? I've bought a couple of plants in the past in an MA store that turned out to be for reptiles (although they don't/didn't actually keep reptiles in store).
 

It is reasonably common unfortunately. Ideally they should have told you this, but the plants do sell and people keep buying them when they dies so there is clear motivation there...