Answer :
Yes, it is true that Plant fiber is a collenchyma cell.
Collenchyma tissue is a tissue which is flexible. It gives plant flexibility and support. That's just what a Plant fiber does. It gives flexibility and support to the plant. So, it is not wrong to call the plant fiber a collenchyma cell.
Collenchyma tissue is a tissue which is flexible. It gives plant flexibility and support. That's just what a Plant fiber does. It gives flexibility and support to the plant. So, it is not wrong to call the plant fiber a collenchyma cell.