Root tip

Root tip [ Botany ]

Dictionary of botanic terminology - index of names

The root tip is the apical growing part of a root.

Roots originate from the radicle of the embryo during the germination of the seed and growth mainly at their tip for the activity of the root apical meristem.
The growing part of a root tip is divided into four regions:

1. Root cap – A cap of cells that protects the apical meristem behind it from abrasion and damage as the root tip grows through the soil.
2. Region of cell division - The growing point (meristem) a region of rapid mitosis, which produces the new cells for root growth.
3. Region of elongation: The zone where cells increase and elongate in size in the direction of the axis of the root. It is at this time that they are sensitive to gravity and respond with gravitropism.
4. Region of maturation (or differentiation): the zone where develop the differentiated tissues of the root. Here are located the root hairs which greatly increase the surface area available for the uptake of water from the soil.

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Holdfast roots [ Botany ]
Dictionary of botanic terminology - index of names

Some species of climbing plants develop holdfast roots which help to support the vines on trees, walls, and rocks. By forcing their way into minute pores and crevices, they hold the plant firmly in place.

Climbing plants, like the poison ivy (Toxicodendron radicans), Boston ivy (Parthenocissus tricuspidata), and trumpet creeper (Campsis radicans), develop holdfast roots which help to support the vines on trees, walls, and rocks. By forcing their way into minute pores and crevices, they hold the plant firmly in place. Usually the Holdfast roots die at the end of the first season, but in some species they are perennial. In the tropics some of the large climbing plants have hold-fast roots by which they attach themselves, and long, cord-like roots that extend downward through the air and may lengthen and branch for several years until they strike the soil and become absorbent roots.

Major references and further lectures:
1) E. N. Transeau “General Botany” Discovery Publishing House, 1994