Does anyone know what this is please-follow up
By Cestina
South Bohemia,
Czech Republic 
I took some more photos as requested - two close ups of the flower. Not sure if I can post two at once? No milky sap when I snapped one off.
Someone here in the Czech Republic suggested a lamium but the leaves are wrong, the flowers don't all open at once and I think it is far too big.....
18 Aug, 2009
Answers
Wonder if its a type of Solanum...it reminds me of a potato flower not fully opened....if so it may belong to the Deadly Nightshade family......in my plant book it does resemble Black Nightshade....which is also poisonous...I would get rid of it myself.
18 Aug, 2009