Malvaceae, I reckon. Perhaps Malva or Lavatera? Is it wild or cultivated?
Best
-- Jan

Osiris wrote:
Could someone please tell me what this is :

http://www.terwiel.com/diversen/DSCN0636.JPG
http://www.terwiel.com/diversen/DSCN0637.JPG (mature flower)

the flower seems to have 12 styles/sigmas and a lot of stamen,
that seem only to differentiate in a mature flowers.

5 petals
2 x 5 sepals
leafs stand singel on the stem
plant 2 ft high (60 cm)
No woody parts.

petals have dark purple veins and lighter purple borders.
on other plants, the border of the petal may be almost white.