Lower leaf (Cataphylle) are usually small and simply decorated, often scaly. In many cases, only the bottom sheet is formed. Usually they are not green. At the shoot axis they are below the leaf, hence the name. They are located at the beginning of base or the runner in woody plants are often referred to as Lower leaf bud scales at the lower end of annual drive (not all the trees bud scales, however, are low-sheets). Here abscission and low leaf area change periodically from each other (wholesale Galax leaves).
Leaf only occur when the scion plants, ie plants with fern (Pteridophyta) and seed plants . Spermatophyta). However, they are absent in mosses and algae, but at the thallus can leaf-like structures occur, but they are only to be considered as analogs of leaf. The abundance of leaf shapes is enormous. In some cases arose in course of evolution foliar organs, with the original function of leaf, namely photosynthesis and transpiration, have nothing more to do.
This is particularly evident in grasses. The main veins and also the many smaller parallel bundles are associated with each other by small, usually visible to naked eye bundles (transverse anastomoses). The parallel arrangement of bundles also leads to a parallel arrangement of stomata.
Exceptions are the epidermis of hygro-, HELO and hydrophytes and partially shade leaf, but especially the guard cells of stomata (stomata), which always contain chloroplasts. The stomata serve the regulation of gas exchange, primarily of water vapor. After the distribution of stomata, a distinction (stomata on the underside of leaf, common type), (stomata on both leaf surfaces) and leaf (stomata on the leaf surface, z. B. With floating leaf).
When two lines or couplets leaf position at each node is only one leaf, leaf consecutive nodes are shifted by 180, thus yielding to stem axis, two longitudinal rows of leaf. Representatives are many monocots and Legume. At constant exchange blade position is also located only one sheet at each node, the angle between two sheets but is different from 180 degrees, the leaf are along a spiral line. This arrangement is characteristic of dicotyledonous plants. When compared basal leaf position, two leaf at each node. When dekussierten or decussate phyllotaxis successive leaf pairs are rotated by 90 degrees, so above the other at right angles. It created four longitudinal rows. Representatives are mint, clove plants and Oleaceae.
For a number of trees such as lime, hornbeam poplar and the stipules are designed as membranous, not green scales, which already fall during the unfolding leaf. In the stipules are transformed to an extension leaf sheath (Ochrea), a membranous sheath that encloses the stem tubular. The ligule (ligule) of sweet and sour grasses that sits at the junction leaf sheath in leaf blade is also a by-sheet.
top sheet
The shape of blade or flake: Specifies whether the sheet, for example, is round, elliptical, linear, kidney-shaped, etc. Leaf describes how leaf blade enters the petiole. Eg, heart-shaped, arrow-shaped. The spreading-Apex (peak), rounded, be sharp, dull, etc. From the Journal of plant leaf hump develops, it differentiates itself by a constriction in a wide proximal portion, the bottom sheet, and a narrow distal portion, the top sheet. Growth occurs only for a short time with the point. The tip is very early in their growth, the growth is by intercalary meristems or basal (untercalary growth).
Leaf only occur when the scion plants, ie plants with fern (Pteridophyta) and seed plants . Spermatophyta). However, they are absent in mosses and algae, but at the thallus can leaf-like structures occur, but they are only to be considered as analogs of leaf. The abundance of leaf shapes is enormous. In some cases arose in course of evolution foliar organs, with the original function of leaf, namely photosynthesis and transpiration, have nothing more to do.
This is particularly evident in grasses. The main veins and also the many smaller parallel bundles are associated with each other by small, usually visible to naked eye bundles (transverse anastomoses). The parallel arrangement of bundles also leads to a parallel arrangement of stomata.
Exceptions are the epidermis of hygro-, HELO and hydrophytes and partially shade leaf, but especially the guard cells of stomata (stomata), which always contain chloroplasts. The stomata serve the regulation of gas exchange, primarily of water vapor. After the distribution of stomata, a distinction (stomata on the underside of leaf, common type), (stomata on both leaf surfaces) and leaf (stomata on the leaf surface, z. B. With floating leaf).
When two lines or couplets leaf position at each node is only one leaf, leaf consecutive nodes are shifted by 180, thus yielding to stem axis, two longitudinal rows of leaf. Representatives are many monocots and Legume. At constant exchange blade position is also located only one sheet at each node, the angle between two sheets but is different from 180 degrees, the leaf are along a spiral line. This arrangement is characteristic of dicotyledonous plants. When compared basal leaf position, two leaf at each node. When dekussierten or decussate phyllotaxis successive leaf pairs are rotated by 90 degrees, so above the other at right angles. It created four longitudinal rows. Representatives are mint, clove plants and Oleaceae.
For a number of trees such as lime, hornbeam poplar and the stipules are designed as membranous, not green scales, which already fall during the unfolding leaf. In the stipules are transformed to an extension leaf sheath (Ochrea), a membranous sheath that encloses the stem tubular. The ligule (ligule) of sweet and sour grasses that sits at the junction leaf sheath in leaf blade is also a by-sheet.
top sheet
The shape of blade or flake: Specifies whether the sheet, for example, is round, elliptical, linear, kidney-shaped, etc. Leaf describes how leaf blade enters the petiole. Eg, heart-shaped, arrow-shaped. The spreading-Apex (peak), rounded, be sharp, dull, etc. From the Journal of plant leaf hump develops, it differentiates itself by a constriction in a wide proximal portion, the bottom sheet, and a narrow distal portion, the top sheet. Growth occurs only for a short time with the point. The tip is very early in their growth, the growth is by intercalary meristems or basal (untercalary growth).
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