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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]
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.
The presence of vessels in xylem has been considered to be one of the key innovations that led to the success of the flowering plants. It was once thought that vessel elements were an evolutionary innovation of flowering plants, but their absence from some basal angiosperms and their presence in some members of the Gnetales suggest that this hypothesis must be re-examined; vessel elements in ...
It forms a protective covering on the leaf vein and consists of one or more cell layers, usually parenchyma. Loosely-arranged mesophyll cells lie between the bundle sheath and the leaf surface. The Calvin cycle is confined to the chloroplasts of these bundle sheath cells in C 4 plants. C 2 plants also use a variation of this structure. [1]
A vascular plant begins from a single celled zygote, formed by fertilisation of an egg cell by a sperm cell. From that point, it begins to divide to form a plant embryo through the process of embryogenesis. As this happens, the resulting cells will organise so that one end becomes the first root, while the other end forms the tip of the shoot.
A hydathode is a type of pore, commonly found in vascular plants, [1] that secretes water through pores in the epidermis or leaf margin, typically at the tip of a marginal tooth or serration. Hydathodes occur in the leaves of submerged aquatic plants such as Ranunculus fluitans [ 2 ] as well as herbaceous plants of drier habitats such as ...
Leaf anatomy in most C 4 plants. A: Mesophyll cell B: Chloroplast C: Vascular tissue D: Bundle sheath cell E: Stoma F: Vascular tissue 1. CO 2 is fixed to produce a four-carbon molecule (malate or aspartate). 2. The molecule exits the cell and enters the bundle sheath cells. 3. It is then broken down into CO 2 and pyruvate.
The epidermis is the outermost cell layer of the primary plant body. In some older works the cells of the leaf epidermis have been regarded as specialized parenchyma cells, [1] but the established modern preference has long been to classify the epidermis as dermal tissue, [2] whereas parenchyma is classified as ground tissue. [3]