This is a compound leaf. The principal function of leaves is to absorb sunlight for the manufacturing of plant sugars in photosynthesis. Leaves develop as a flattened surface in order to present a large area for efficient absorption of light energy. Some plants have leaves that can be used for propagation.
When propagating a plant by a leaf or leaf section, it is important to identify some of the properties of the plant’s leaves. For example, are they simple or compound? Are they arranged on the stem in an alternate or opposing pattern? Are they sessile or petiolate? There are many factors that can aid or hinder successful propagation using the leaves.
Simple or Compound
To begin with, the basic leaf structure should be identified. Is the leaf simple or compound? A simple leaf has a single blade protruding from a node on the stem such as pothos or maple. A compound leaf is composed of multiple leaflets protruding from the same node such as a fern, Ming Aralia, or Schefflera. When speaking of “leaves” with regard to propagation, a compound leaf should be treated as a single leaf rather than treating each leaflet as its own leaf.
Petiollate or Sessile
Petiolate leaves have a leafstalk (or petiole) that attaches to the plant stem. However, the leaves of some plants, like Jade plant, lack petioles and are attached directly to the plant stem. These are called sessile or unstalked leaves.
Veins are the vascular bundles from the stem that extend through the petiole (if present) and spread out into the leaf blade. There are two main types of vein patterns in leaves: parallel-veined and net-veined. Parallel-veined leaves contain numerous veins that run essentially parallel to each other and are connected laterally by tiny, straight veinlets. Grass is a common example of parallel-veined leaves.
Net-veined or reticulate-veined leaves have veins that branch from the main midrib and then subdivide into finer veinlets, which then unite in a complicated network. This system of enmeshed veins gives the leaf more resistance to tearing than most parallel-veined leaves. Examples of net-veined leaves include those of apples, grapes, and maple trees.
Roots absorb nutrients and water from the soil in addition to helping stabilize the plant. Not only are roots important because they absorb nutrients and water from the soil and help stabilize the plant, but they also can play an important part in propagation. By starting with the roots, the new plant already has the ability to draw nutrients from the soil, unlike propagation by stems or leaves, which requires the new plant to form its own roots. Before you attempt to propagate a plant by its roots, you should learn to identify the different types of rooting structures and the specific purpose they serve for the plant. Then you will understand how to properly propagate a plant through division using its roots.
Fibrous roots are the most common root type. They are roots that continually branch and re-branch beneath the soil just like arteries and capillaries in the human body. African violets are a good example of a fibrous structure. These roots are fine, extremely flexible, and are generally formed from nodes on the base of the plant. Therefore, multiple stalks of a plant with fibrous roots are actually multiple plants.
Tap root and lateral rootlets. Tap roots occur when the primary root growing downward is much larger than the secondary roots. Carrots, cedars, and cypress are all good examples of tap root systems. A tap root can often penetrate the soil far deeper than the height of the plant above the soil. However, as the plant’s primary source of nutrients from the soil, any damage to the tap root can have catastrophic effects on the overall health of the plant. Tap roots are often surrounded by fine fibrous roots that spread out laterally to retrieve nutrients more efficiently from different levels of the media.
A tuber, such as a potato, is not technically a root, but is actually an enlarged portion of an underground stem that stores food and water for the plant. Tubers are thick and inflexible because they are full of water and nutrients taken from the media.
Some plants, such as sweet potatoes, peonies, and hostas, have tuberous roots that store food and water for the plant. While they have thick and inflexible sections like tubers, they are a type of root rather than a type of stem.
So how do you recognize the difference? A true tuber, just like any other stem, has nodes that produce buds. Each true tuber can be used to grow a single plant. A tuberous root does not have nodes. Instead, several tuberous roots are joined at a stem to form a single plant.
Bulbs are shortened, compressed, underground stems, surrounded by leaves. Bulbs are shortened, compressed, underground stems that are surrounded by fleshy scales (leaves) that envelop a central bud located at the tip of the stem. If you cut through a tulip or daffodil bulb in November, you can see all the flower parts in miniature within the bulb. A single bulb will sprout into a single plant with a fibrous root system. However, for the purpose of propagation, we are not concerned with the fibrous roots directly. Instead, we are interested in the bulb and roots together. Bulbs form bulblets, which mature into bulbs. Each one can be removed to form new plant.
Rhizomes are underground stems with nodes, buds, or scale-like leaves. Rhizomes are underground stems distinguishable from roots by the presence of nodes, buds, or scale-like leaves. Rhizomes, like tubers, are thick and inflexible, but have an important distinction. Rhizomes create a horizontal runner allowing the plant to spread, while tubers form in a radius underneath a plant. Plants with tubers or tuberous roots will form dense clumps, while plants with rhizomes form colonies of individual plants. Ferns and irises are good examples of rhizomes.
Corms are solid, swollen stems with scales that have been reduced to a dry, leafy covering. The term “corm” is often used interchangeably with “bulb,” but they are not the same. Corms have shapes similar to bulbs but do not contain fleshy scales. A corm is a solid, swollen stem with scales that have been reduced to a dry, leafy covering. However, like bulbs, corms will form cormels, which can be divided to form new plants. Crocus and gladiolus are popular examples of corms.
Stems must have buds or leaves present to be classified as stem tissue. Stems may be long, with great distances between leaves and buds (such as branches of trees) or compressed (such as strawberry plants). They can be above ground like most stems with which we are familiar, or below ground (such as potatoes or tulip bulbs). All stems must have buds or leaves present to be classified as stem tissue.
Stems support buds and leaves and serve as conduits for carrying water, minerals, and sugars throughout the plant. They also provide the general shape of the plant and help it to hold that shape. Several stem structures are important in propagation
Stems are composed of segments called nodes. Stems are composed of segments called nodes. The area between nodes is called the internode. The internode can be of a substantial length, as with some vines, or almost inconspicuous, as with an African violet. The length of an internode depends on many factors such as the season, growth rate of the plant, competition from surrounding plants, and light conditions. To successfully grow a plant from a stem cutting, the section of stem you choose should be healthy and contain nodes and internodes.
Buds are responsible for plant growth, including new stems, flowers, or leaves. Buds are responsible for plant growth, including new stems, flowers, or leaves. As such, they take different forms: • Main Terminal – responsible for the upward growth of the plant. For a plant with a strong vertical habit, this is found on the leader stem • Secondary Terminal – comes out from the tip of secondary stems and makes them grow • Lateral – occurs on stem nodes and is the origin for leaves and flowers • Axillary – present in the axil (between the leaf and the stem) where branches and flowers form
Bark is the external skin of a woody plant. Bark is the external skin of a woody plant such as a fruit tree, ornamental tree, or shrub. Its main functions are to protect the growing stem and to allow air to pass into the living portions of the stem. Because the stem is constantly growing in circumference, the bark is shed periodically.