This wall is a basket-weave of cellulose microfibrils. These are cross-linked with other polysaccharides. Peter Albersheim spent his career studying the composition of sycamore cell walls. Together, the microfibrils and cross-links make the wall very ridgid. It can withstand the turgor pressure induced by osmosis in hypotonic environments.
Most plant cells exist in that kind of setting.
The cellulose fibrils cannot be cut, or the turgor would cause the cell to burst in the area where the fibrils are cut. The turgor pressure causes the membrane to open. Instead, for the cell to grow, the hemicellulose and pectin cross links must be severed. This permits the cell to expand. If the microfibrils are oriented randomly, then the cells will expand in all directions, remaining isodiametric.