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A leaf (pl.: leaves) is a principal appendage of the stem of a vascular plant, [1] usually borne laterally above ground and specialized for photosynthesis.Leaves are collectively called foliage, as in "autumn foliage", [2] [3] while the leaves, stem, flower, and fruit collectively form the shoot system. [4]
Autoicous – produces male and female sex organs on the same plant but on separate inflorescences. Bract – leaf is present below the flower. Cladautoicous – male and female inflorescences are on separate branches of the same plant. Dioicous – having two forms of gametophyte, one form bearing antheridia and one form bearing archegonia.
The lobed leaves come from the base of the plant, while the unlobed leaves come from the top of the plant. There is variation among the parts of a mature plant resulting from the relative position where the organ is produced. For example, along a new branch the leaves may vary in a consistent pattern along the branch.
The form of leaves produced near the base of the branch will differ from leaves produced at the tip of the plant, and this difference is consistent from branch to branch on a given plant and in a given species. This difference persists after the leaves at both ends of the branch have matured, and is not the result of some leaves being younger ...
Plant anatomy or phytotomy is the general term for the study of the internal structure of plants.Originally, it included plant morphology, the description of the physical form and external structure of plants, but since the mid-20th century, plant anatomy has been considered a separate field referring only to internal plant structure.
Leaf marcescence is most often seen on juvenile plants and may disappear as the tree matures. It also may not affect the entire tree; sometimes leaves persist only on scattered branches. [4] Marcescence is most obvious in deciduous trees that retain leaves through the winter.
Organography as a scientific study starts with Aristotle, who considered the parts of plants as "organs" and began to consider the relationship between different organs and different functions. In the 17th century Joachim Jung, [ 1 ] clearly articulated that plants are composed of different organ types such as root, stem and leaf, and he went ...
The functions of a plant's growing tips – its apical (or primary) meristems – include: lengthening through cell division and elongation; organising the development of leaves along the stem; creating platforms for the eventual development of branches along the stem; [4] laying the groundwork for organ formation by providing a stock of ...