Other modifications include the uneven thickening of guard cells, the sieve plates in phloem, the suberization of endodermal cells, the waterproof coverings of epidermal and cork cells.

• 此外还有其他的一些修饰形式，包括不均匀的加厚保卫细胞和韧皮部中的筛板，内皮细胞的栓化等。