[I-Am-Steptoe]

Hi everyone, this is my first post on the forum and I am new to gardening aswell, I recently moved home and thought I'd put my name down to see if I could get myself a small allotment plot, which by some stroke of luck I did.
It's only small but more than adequate for me.
Anyway, my question is this, I purchased some seeds from poundland, and on the packet it said one of the seed packs was Radicchio Lettuce. Not personally being a big fan of Lettuce I thought I'd plant them to try it and see what it is like compared to normal Lettuce for a change. The picture on the packet shows the normal/usual Red & White Radicchio type plant, but what I have got growing isn't even close to resembling anything near that.
Here's a couple of pics so you can see what I mean, I've got approx 50/50 of each shape give or take.
Any advice would be champion as I am a complete novice at self-sufficiency, and thank you for your time too.

[Trillium]

It's possible you got a variety pack of radicchio and the supplier simply used the most recognizable variety so people would know what it is. There are a number of different types that are described here.

All are edible even if unexpected. I don't grow radicchio so not familiar with the varieties you have but the link should tell you.

[Madame Cholet]

looks really good though well done

[BabbyAnn]

The top one looks like Rossa di Trevise and the one below looks like Palla Rossa - both radicchio as Trillium suggested.  Radicchio means red chicory - you'll find they can taste bitter compared to lettuce and usually you shred/tear pieces and add to the salad bowl for a little extra colour

[sunshineband]

On the plus side, you have healthy plants which will be delicious to eat

Well done   

[I-Am-Steptoe]

Hi Trillium, Rachelk, BabbyAnn &  Sunshineband.

Thanks for taking time to reply, like you say, I've read that they can be a bit bitter if not picked early, but how do I know when it's the right time to pick them?

Should I pick them now or do I need to give them a bit longer yet?

Neither type are developing any tight heads, they are just more like loose leaved varieties.

[BabbyAnn]

If you have several plants you can start harvesting one at a time from now, but if you only have a few, why not pick off the outer leaves (obviously discard the tatty ones/compost) and leave the inner ones to keep producing 

[mumofstig]

they are slightly bitter whenever you pick them 

The bottom pic looks like the sort that will make a head if left to develop - they can take months, as they are a winter salad.

[I-Am-Steptoe]

Aah right, so they may well form compact/tighter heads in a few weeks then, I didn't realise they were a winter salad crop.