What is a scar in plants?

What is a scar in plants?

A leaf scar is the mark left by a leaf after it falls off the twig. It marks the site where the petiole attached to the stem. A leaf scar is typically found below a branch as branches come from axillary buds located above leaf scars.

What is always present at the base of the leaf petiole?

Lamina – The blade-shaped part of a leaf where transpiration and photosynthesis take place. Stipule – A small attachment that can be found at the base of a petiole, resembling a leaf.

What is a Stipule scar?

Definition. Referring to the scars left on the stem after the stipules have fallen. Because many stipules are caducous, one has to look carefully for scars to determine if stipules were present at an earlier stage of development.

Why do stems have scars?

In general, at the tip of a twig a terminal (or ending) bud is present. It is larger than the axillary buds and produces tissues to extend twig length during the growing season. When the bud scales of a terminal bud fall off they leave scars on the twig.

Is scar part of a seed?

A scar can be seen at the end or along the side of the seed coat. It is called the hilum. The hilum marks the point of attachment of the seed to the ovary wall.

What are leaf petioles?

A plant leaf is generally composed of a petiole and a leaf blade. The petiole connects the leaf blade to the plant stem and, from a structural viewpoint, it resembles a cantilever beam. Petiole design is driven by the minimum use of material to withstand a combined torsion and bending load.

Where is sessile leaves present?

Structure of a Typical Leaf Leaves that do not have a petiole and are directly attached to the plant stem are called sessile leaves. Leaves also have stipules, small green appendages usually found at the base of the petiole.

What is a Diaphragmed pith?

Twigs can have one of five dominant types of pith: 1) solid (homogenous or entire) pith is uniform soft tissues with no cavities or cross walls; 2) diaphragmed (septate) pith is solid with thin cross walls; 3) spongy pith is perforated with holes; 4) excavated pith is hollow or empty; and, 5) chambered (discoid) is an …

What is in the middle of a leaf scar?

leaf scar. Within each leaf scar there are one or more bundle scars, each representing a cross-section of vascular bundles that ran from the branch into the petiole when the leaf was attached.

What is the difference between leaf scar and bundle scar?

a leaf scar is the scar remaining after the leaf falls off. Bundle scars are the broken ends of the vascular bundles passing from the stem into the leaves. They are identified as small dots, discolorations, or raised bumps on the surface of the leaf scar ( not very visible here).