Hi Leni,
A very famous mould this, originally a vase in the Inwald "Barolac" range, pattern number 11589. "Forest" was produced from the 1930s onward and is now being made by Halama as product number FH4026/27cm. In sodium-potash glass, height should be 270mm. This does unfortunately look like it may be a post-war production.
Regards,
Marcus