piliferous layer

(root-hair zone) The absorbing region of the root *epidermis , covered with *root hairs. It is situated about 4-10 mm from the root tip (beyond the zone of elongation). In young plants this region is responsible for most of the plant's water uptake. However in larger older plants and in conditions of water stress a greater proportion of water moves in across the suberized regions of the root further back from the root tip.