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In botany, a stoma (pl.: stomata, from Greek στόμα, "mouth"), also called a stomate (pl.: stomates), is a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange between the internal air spaces of the leaf and the atmosphere.
The leaf and stem epidermis is covered with pores called stomata (sing; stoma), part of a stoma complex consisting of a pore surrounded on each side by chloroplast-containing guard cells, and two to four subsidiary cells that lack chloroplasts. The stomata complex regulates the exchange of gases and water vapor between the outside air and the ...
Cladode – a flattened stem that performs the function of a leaf; an example is the pad of the opuntia cactus. Cladophyll – a flattened stem that is leaf-like and green – used for photosynthesis. Normally such plants have no, or greatly reduced, leaves. Climbing – typically long stems that cling to other objects.
Photosynthesis depends on the diffusion of carbon dioxide (CO 2) from the air through the stomata into the mesophyll tissues. Oxygen (O 2), produced as a byproduct of photosynthesis, exits the plant via the stomata. When the stomata are open, water is lost by evaporation and must be replaced via the transpiration stream, with water taken up by ...
The upper angle between one part of a plant and another, e.g. the stem and a leaf. axile On an axis; of a placenta, on the central axis of the ovary. axillary Borne in or arising from the axil, usually referring to the axil of a leaf. axis The main stem of a whole plant or inflorescence; also, the line along which this stem extends.
stem attachment: A round leaf where the petiole attaches near the center, e.g. a lotus leaf perfoliate: perfoliatus: stem attachment: With the leaf blade surrounding the stem such that the stem appears to pass through the leaf perforate: perforatus: leaf surface features Many holes, or perforations, on leaf surface. Compare with fenestrate ...
Also found among the Roman coins were 72 gold aurei, dated from 18 B.C. to 47 A.D. Those coins show no signs of wear and likely came from a pile of freshly minted coins, according to the Cultural ...
The stem can also be called the culm, halm, haulm, stalk, or thyrsus. The stem is normally divided into nodes and internodes: [2] The nodes are the points of attachment for leaves and can hold one or more leaves. There are sometimes axillary buds between the stem and leaf which can grow into branches (with leaves, conifer cones, or flowers). [2]