Basic unit of the plant body is the cell. It differs from an animal cell in that it has a cell wall made up of cellulose. This is called the primary wall and these cells arise from the apical meristem. Page 571 diagram on bottom of page showing the origin of cells at the apical meristem.
Cells make up tissues.
A tissue is a group of cells with a specific function in the plant. Tissues can be simple or complex. There are three basic cell types in plants. E.G. the cortex of the root. Primary function is storage.