Lobe

Lobe [ Botany ]
Adjective: lobed

Dictionary of botanic terminology - index of names


	Usually a rounded segment or portion of an organ, hence lobed means bearing lobe(s) or whit the shape of a lobe.

(1) Lobe (leaf) [ Botany ]

A leaf lobe is a partial rounded portion of a le af margin, separated from the whole by a more or less deeply indentation (sinus) that does not break the continuity of the structure (deeper than the ones it may have if it is toothed (serrate) but less than halfway to the midrib) Lobes only at the base of the leaf do not count.

Lobe vs. tooth: It is not clear what is the difference between teeth and lobes; a general but not exhaustive definition is: “ Lobes are marginal indentations that reach ¼ or more of the distance to the midvein, measured parallel to the axis of symmetry of the lobe, tooth are less than ¼”.

(2) Lobe (flower) [ Botany ]


	A flowers lobe is a petal divided by more or less deeply cuts (sinus) that does not break the continuity of the structure and opening into petal-like segments.

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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