Axis

Axis [ Botany ]
Adjective: Axial

Dictionary of botanic terminology - index of names


	In geometry an axis is the central line of a body or part thereof, especially the imaginary line around which rotation takes place. In botany an axis is the main stem of a plant, or a central line of symmetry, development, or growth around which plant organs or parts are arranged both in plan and in elevation.

The axis of a plant runs through the middle of it, e.g., the central stem of a plant to which organs or parts are attached, the primary root or the stalk (rachis) of a compound leaf or of an inflorescence.

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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