7: Stems

Conducting tissues

Definition:Tissues in stems that transport water and minerals from the roots to the leaves and nutrients via phloem to the roots, flowers, and young leaves.

Aerial support

Definition:The function of stems to provide support for leaves above the ground.

Photosynthetic stems

Definition:Stems that are capable of photosynthesis.

Modified stems for storage

Definition:Stems that have been modified to store nutrients, such as potatoes and ginger.

Diminished stems

Definition:Stems that are less prominent but still serve important functions, such as in carnivorous plants where they anchor the leaves.

Herbaceous stems

Definition:Stems that are green, fleshy, and flexible, and have not undergone significant secondary growth.

Woody stems

Definition:Stems that have undergone secondary growth, developed a periderm, are harder or firmer, and less flexible.

Node

Definition:A point of attachment on a stem, typically for a leaf or a flower.

Internode

Definition:The area of the stem between two nodes.

Axillary bud

Definition:A structure composed of a dormant apical meristem and scales covering it, occurring specifically in the angle between a leaf attachment and the main stem axis.

Terminal bud

Definition:A dormant apical meristem covered by scales at the apex or end of the stem or stem branch.

Leaf (petiole) scar

Definition:The location where a leaf was once attached to the stem, with visible vascular bundle scars.

Terminal bud scale scars

Definition:A ring-like array of scars indicating the location of a previous terminal bud.

Lenticels

Definition:Small perforations in the periderm of woody stems through which limited gas exchange may occur.

Opposite leaf arrangement

Definition:A leaf arrangement where there are two leaves per node.

Alternate leaf arrangement

Definition:A leaf arrangement where there is one leaf per node.

Whorled leaf arrangement

Definition:A leaf arrangement where there are three or more leaves per node.

Monocot stem anatomy

Definition:Stem anatomy characterized by scattered vascular tissue arrangement, absence of pith, and presence of cortex cells.

Dicot stem anatomy

Definition:Stem anatomy characterized by vascular tissue arrangement in a ring, presence of pith, and presence of cortex cells.

Potato

Definition:A stem of the Solanum species in the nightshade family (Solanaceae) found in temperate climates.

Sweet Potato

Definition:A root of the Ipomoea species in the morning glory family (Convolvulaceae) found in subtropical regions.

Yam

Definition:A stem of the Dioscorea species in the yam family (Dioscoreaceae) found in tropical regions.

Anatomical patterns in roots and stems

Definition:The specific anatomical features that can be expected to differ between the roots and stems of these plants.

Distinguishing roots and stems based on external features

Definition:Identifying whether a plant part is a root or a stem by observing its external characteristics.

Distinguishing monocot and dicot stems

Definition:Differentiating between monocot and dicot stems based on their external and anatomical features.