You are right, it's Chenopodium album or Fat Hen. What was it supposed to be?

Thank you both (sorry abut the carrots - how annoying!). I can't remember what those seeds should have been as I bought several at the same time - I'll need to do a process of elimination as they all start to flower (hopefully!)

wow, I never heard of such a thing - weed seeds in a flower packet! I'd be flippin mad! You must have the patience of Mother Theresa.

Hi, I think that is about par for the course with t&m, Derek.

Years ago T & M used to be one of the best seed merchants with a huge variety of novel seeds. Now they seem to have gone rapidly downhill and no-one has a good word for them. Has the company changed hands does anyone know?

Hi, apparently an investment group called primary capital, own a 52% share in the company, and the management, the other 48%, so it looks as if they're just out to make money, and never mind the quality of their products, Derek.

Take a photo and send it to the CEO, you can find his email on the internet.....theres a voluntary run site that has an alphabetical list of big companies emails....
works like a charm!

The trouble is, its entirely possible that the seeds sown didn't come up, and this fat hen is simply a seed either already present in the compost, or one that blew in. And I'm 100% certain that's what T & M will say, specially since you can't recall what you sowed in the first place. If it wasn't an annual plant, it might have needed particular conditions for germination and growth to take place anyway.

Well thanks everyone for the advice/comments - I used Thomson and Morgan because I thought they were reliable - seems like I was misguided! - though I won't use them again.

Sorry you were unlucky, Plymouth g. There are so many websites for seeds, but I've been very happy with seedaholic's comprehensive sowing instructions, and had brilliant service from Plant World Seeds who TWICE have sent replacements for seeds which didn't germinate.