Stems

Conifer

"Cone Bearing" woody dicot. The wood in these is relatively soft because the xylem consists only of tracheids, with no vessels or fibers

Axillary Bud

A bud that develops in the axil of a leaf of a plant (synonymous with lateral bud).

Stele

A central cylinder in some stems, consisting of a solid core of conducting tissues. In this type of cylinder, phloem tissues surround xylem tissues. Not commonly found in modern plants.

Cladophyll

A flattened stem that looks like a leaf (Example: Prickly cactus, asparagus)

Ray

A radiate band of parenchyma cells extending from the vascular cambium through the secondary xylem extending into the secondary phloem of the stems of certain vascular plants, formed by the cambium and serving for the storage of food and the conduction of nutrients.

Tendril

A specialized stem, leaf or petiole with a threadlike shape that is used by climbing plants for support, attachment and cellular invasion by parasitic plants, generally by twining around suitable hosts

Bark

All of the tissues outside the cambium, including the phloem

Inner bark

Composed of Primary and secondary phloem

Outer bark

Composed of cork cambium and cork tissue

Pith

Composed of soft, spongy parenchyma cells, which store and transport nutrients throughout the plant. Located in the center of the stem.

Cork Tissue

Cut off water and food supplies to the epidermis, which is why the epidermis is just dead tissue on woody plants.

Tuber

Develop from Stolon

Annual Ring

Each of a number of concentric rings in the cross section of a tree trunk, representing a single year's growth

Primary Tissue

Epidermis, Primary Xylem, Primary Phloem, Pith, Cortex.

Lenticel

Functions as a pore on stems, providing a pathway for the direct exchange of gases between the internal tissues and atmosphere through the bark, which is otherwise impermeable to gases

Companion Cell

Have a nucleus, and help the sieve tube members of phloem (which have no nuclei) do their job.

Eustele

In modern plants, these consist of paired vascular bundles of xylem and phloem.

Phelloderm

In woody plants, this is another word for the CORK CELLS that are filled with SUBERIN - for permeability against water.

Pith

Inner layer made by ground meristem.

Bulb

Large buds that are surrounded by fleshy leaves. Small stem at lower end. These store food. (Example: Daffodils, tulips, onions)

Corm

Like a bulb, but with stem tissue instead of leaf tissue. Stores food. (Example: Crocus, Garlic)

Primary Phloem

Made by Procambium. Transports sugars and other substances produced by photosynthesis in the leaves downward through the plant and for storage.

Primary Xylem

Made by Procambium. Transports water upward through plant.

Sheath

Made up of sclerenchyma cells, surrounds the vascular bundle.

Monocot Stem

Most are herbaceous and don't grow very large. Have neither a vascular cambium or cork cambium.

Monocots

Most have no cortex and no pith layer

Vascular Bundle

Oriented so that the xylem is closer to the inside of the stem and the phloem closer to the outside.

Cortex

Outer layer made by ground meristem.

Sapwood

Outside of the heartwood, this continues developing. Develops at the same rate as heartwood.

Protoderm

Part of the apical meristem that develops into epiderm

Ground Meristem

Part of the apical meristem that produces pith and cortex.

Procambium

Part of the apical meristem, inside the protoderm. Produces primary xylem and primary phloem. Develops vascular cambium.

Secondary Tissue

Produced by the vascular cambium. Contribute to girth/width of the stems and trunks.

Vascular Cambium

Produces secondary xylem and phloem

Apical Meristem

Protected by bud scales. Area of primary growth. Primordial leaves inside.

Resin Canal

Scattered through xylem, The cells secrete resin

Summer Wood

Secondary xylem produced in greater volume/quantity of tracheids than vessels. Seen in annual ring of tree.

Spring Wood

Secondary xylem produced in large vessels. Seen in annual ring of tree.

Rhizome

Specialized horizontal stem, grows beneath surface of soil. Possess axillary buds (nodes) along stem. Leaves develop at bud. Will develop adventitious roots from bottom.

Stolon

Specialized horizontal stem, that run beneath surface of ground. Sometimes tips develop into TUBERS.

Runner

Specialized horizontal stem, that run on top of ground with long internodes. Grow fast, and develop adventitious roots. (Example: Bermuda Grass)

Node

The area where a leaf attaches to the stems

Heartwood

The dark center of the trunk. Purpose is to provide strength and support. Sometimes this rots away.

Internode

The region between successive nodes

Protoplasts

These parts of parenchyma cells grow through the pith and block unwanted substances from entering through ray cell.

Herbaceous Stems

This type of stem is composed mainly of primary tissues. Vascular bundle produces patches of primary xylem and primary phloem.

Cortex

Tissue of the ground meristem. Stores food and can manufacture food if there are chloroplasts present. This tissue is crushed and is crushed by other tissues.

Vascular Bundle

Usually has two large vessels and several smaller vessels.

Xylem

What "wood" is made of

Grasses and grains

have an intercalary meristem at the base of each node, contributing to length growth, like the apical meristem.

Vascular Cambium

lateral meristem that produces new xylem to the inside and phloem cells to the outside in the stem and roots