Hi cioc1212, ANY food can cause allergic reaction, especially, like you said, grasses.
The Latin name for flax is: Linum usitatissimum. I'm looking in a PDR, and it does not specify that it is a grass. It is listed as an annual, flowering plant that grows 20 - 250cm high. There are no listed side effects or health hazards with therapeutic dosage.
Hope this helps
------------------
Copper
Let Miracles Replace all Grievances