I think this is the right species.
Total guess but I think this is what this is. The last photo may not even be this, but I saw the flower coming out of what to me looks like these pods so added it also. That one was about 600mm high.
Let me know if I should remove that one if it is something else.
Briza is a genus of annual and perennial grasses in the family Poaceae, native to northern temperate regions. The group is generally referred to as the quaking grasses because the flowers and seedheads shake on their stalks in the slightest breeze. Some of its members are grown as ornamental plants.