Dictionary » L » Leaf



to shoot out leaves; to produce leaves; to leave; as, the trees leaf in May.

Origin: oe. Leef, lef, leaf, as. Leaf; akin to s. Lf, OFries. Laf, D. Loof foliage, g. Laub,OHG. Loub leaf, foliage, Icel. Lauf, Sw. Lof, dan. Lov, goth. Laufs; cf. Lith. Lapas. Cf. Lodge.

1. (Science: botany) a coloured, usually green, expansion growing from the side of a stem or rootstock, in which the sap for the use of the plant is elaborated under the influence of light; one of the parts of a plant which collectively constitute its foliage.

Such leaves usually consist of a blade, or lamina, supported upon a leafstalk or petiole, which, continued through the blade as the midrib, gives off woody ribs and veins that support the cellular texture. The petiole has usually some sort of an appendage on each side of its base, which is called the stipule. The green parenchyma of the leaf is covered with a thin epiderm pierced with closable microscopic openings, known as stomata.

2. (Science: botany) a special organ of vegetation in the form of a lateral outgrowth from the stem, whether appearing as a part of the foliage, or as a cotyledon, a scale, a bract, a spine, or a tendril.

in this view every part of a plant, except the root and the stem, is eith ebd er a leaf, or is composed of leaves more or less modified and transformed.

3. Something which is like a leaf in being wide and thin and having a flat surface, or in being attached to a larger body by one edge or end; as: a part of a book or folded sheet containing two pages upon its opposite sides. A side, division, or part, that slides or is hinged, as of window shutters, folding doors, etc. The movable side of a table. A very thin plate; as, gold leaf. A portion of fat lying in a separate fold or layer. One of the teeth of a pinion, especially when small.

(Science: zoology) leaf beetle, any beetle which feeds upon leaves; especially, any species of the family Chrysomelidae, as the potato beetle and helmet beetle. Leaf bridge, a draw-bridge having a platform or leaf which swings vertically on hinges.

(Science: botany) leaf bud, a sawfiy. To turn over a new leaf, to make a radical change for the better in one's way of living or doing. They were both determined to turn over a new leaf. (Richardson) The main organ of photosynthesis and transpiration in higher plants.Produce leaves, of plants.The photosynthetic region of plants, where different species exhibit different types of leaves to suit their function. This diversity of plant leaves has been brought about by natural selection attempt.

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Need some help in this bio question

Hi There, I need some help with concepts related to Mendel and the Gene. Here are the questions: 1) Given that The leaf shape gene of a plant has two alleles: A and a. A is completely dominant to a, and results in oval, rather than round leaves. Given the following cross, what is ...

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by bradnoell
Thu Feb 05, 2015 2:33 am
Forum: Genetics
Topic: Need some help in this bio question
Replies: 0
Views: 386

What is Epidermis,Hypodermis and endodermis of plants?

... types of tissues systems in different parts of the plant.(And you are right-epidermis is the outermost layer being common in root,stem or leaf).It depends on which one you want to know?Root,stem or leaves? OK,so let me briefly tell about the tissue system in a stem- (Following data are ...

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by Athira
Thu Jan 15, 2015 4:20 pm
Forum: Botany Discussion
Topic: What is Epidermis,Hypodermis and endodermis of plants?
Replies: 2
Views: 2766

Transpiration and Photosynthesis.

... for photosynthesis to take place there needs to be gas exchange through the stomatal pores predominantly found on the lower sides of the leaf. If these pores are closed very little water can evapourate (transpire). So if there are low levels of photosynthesis (say, at night) then there ...

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by Babybel56
Fri Mar 14, 2014 4:07 am
Forum: Botany Discussion
Topic: Transpiration and Photosynthesis.
Replies: 4
Views: 5721

Caterpillar identification

... probably would never reach its food plant. You could try going round all the plants that you would have brushed against and picking a tiny bit of leaf off each and then give them to him and see which one he goes for. Or look up caterpillars on a site and try to match him.

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by animartco
Sat Sep 07, 2013 5:05 pm
Forum: Zoology Discussion
Topic: Caterpillar identification
Replies: 1
Views: 1416

Re: Pterydophyta

... at the surface or underground. Many leaves grow from rhizomes and make fern colonies. Fern leaves are called fronds. Fronds have a petiole (leaf stalk) and blade (main part of leaf). Each leaf has smaller leaflets called pinnae. Instead of flowers, ferns have sori, which grow directly on ...

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by Anonymous
Sun Aug 04, 2013 12:52 pm
Forum: Botany Discussion
Topic: Pterydophyta
Replies: 30
Views: 26740
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