A tangential section is a longitudinal section of a stem where the section is perpendicular to the tangent or radius of the stem. The section will be perpendicular to the vascular rays, so therefore only the ends of the rays will be visible.
DIAGRAM: Stem Sections / Tangential Section
DIAGRAM: Root Systems
PHOTO: Puccinia / Puccinia / Puccinia
DIAGRAM: Biome Comparison
PHOTO: Narcissus / Narcissus / Narcissus / Narcissus / Narcissus
Terminal buds are buds that are at the apex or tip of the stem. These buds are the dominant buds meaning that they cause all the lateral buds below them to remain dormant at all times of the year.
Dicot Stem Morphology
Terminal meristem is the same as the apical meristem. It is the meristem at the tip end of the stem.
PHOTO: Marchantia / Marchantia
A thorn is a modified stem that is sharp and helps to protect a plant from damage by animals.
The torus is the thickened glob of secondary wall in the center of a bordered pit.
(amounts of micronutrients
Tracheids are conducting cells in the xylem that are dead when functioning. They are characterized by containing lignin in their cell walls and thus stain red. They are long and slender with very oblique end walls for increasing the surface area. They contain pits.
Monocot Vascular Bundle
Stem Cross Section
6-Year Tilia Stem Cross Section
Pinus Stem Radial Section
Transfer cells have the morphology of parenchyma cells, but they function much differently. Their job is to carry materials in across their cell membrane and deposit these materials somewhere else, carrying them across their cell membrane as it is deposited either in another cell or where it can be picked up by another cell. These cells contain a greater proportion of mitochondria, clustered along the plasmalemma, for the production of energy for this cellular pumping action.
Transfer cells are abundant in the mesophyll of leaves. They exist along the veinlets where they pick up glucose from the mesophyll, convert it into sucrose, and deposit it in the sieve-tube member.
(energy from one form to another)
Transpiration occurs while photosyntheis is occuring. While the stomata are open for gas exchange, water vapor evaporates from the surface of the spongy parenchyma and escapes out through the stomata into the atmosphere. The loss of water by this means from the plant is called transpiration.
(as in capsule)
Trichomes are plant hairs on the surface of the epidermis of any plant organ that contains an epidermis, including stems, leaves, and fruits. They are simple, branched, scale-like and glandular.
DIAGRAM: Leaf Bases
A tuber is a modified stem that contains nodes and internodes. It is underground and is attached to a rhizome. It is really the swollen portion of a rhizome where large amounts of food are stored, generally starch. A good example of a tuber is a potato. It is possible to find the terminal bud and the lateral buds. The eyes of the potato are these buds. When potatos are planted, the potato is cut up in pieces so that each piece has an eye. Each eye will sprout a new stem and the portion of attached potato will provide the food necessary to get the plant started growing.
Tyloses are parenchyma cells that grow inside vessel elements for the sole purpose of plugging them up. This typically occurs in the vessels adjacent to an abscission zone so as to prevent the vessels from bleeding or being infected by fungal spores or bacteria.