This lesson will explore the characteristics of a large group of plants known as vascular plants.
The lesson will also focus on the different types of vascular plants and unique examples.
Think about the largest tree you have ever seen. How do you think the tree moves water and food through that very tall trunk? Some types of plants, known as vascular plants, have a system of vessels within them that carry water and food throughout the plant. These vessels are found in the roots, stems, and leaves of the plant.The vascular vessels are divided into two types based on what they transport.
The phloem are vessels on the outer layer of the stem that transport food materials, such as sugars from the leaves where they are produced or from storage tissues, to the rest of the plant. If a tree is cut, you can often see sap seep out of the tree, and this is the contents of the phloem. If you have ever had maple syrup, it is the processed form of the sap that is found in the phloem of maple trees. The second type of vascular vessel is the xylem; these are the vessels that transport water throughout the plant. The xylem vessels carry water from the roots up the plant and to the leaves.
Not only do vascular vessels help plants move water and food more efficiently throughout the plant, they also make it possible for the plant to grow larger. By having these vessels, plants can move necessary supplies farther and therefore grow larger. These vascular vessels are similar to the closed circulatory system of humans, because both systems transport nutrients and allow the organisms to grow larger due to the ability to transport farther.Common examples of vascular plants include trees, shrubs, grasses, flowering plants, and ferns. In Grand Canyon National Park, in the United States, there are over 1,700 known species of vascular plants.
Many of these plants are also endemic to this park, meaning that they are only known to exist in this specific area.
Types of Vascular Plants
The general characteristics associated with vascular plants incorporate a broad range of plants, and therefore these plants can be divided further into more specific categories. Vascular plants can be divided by their method of reproduction. Vascular plants that reproduce by the use of spores are characterized as ferns. This type of vascular plant is often referred to as a seedless vascular plant.
The majority of vascular plants reproduce by creating seeds rather than spores and are classified as either gymnosperms or angiosperms. Gymnosperms are vascular plants that create cones to house their seeds. Common gymnosperms include large trees, such as cedars, hemlocks, pines, and spruces.Angiosperms are vascular plants that create their seeds inside fruits or flowers and are often referred to simply as flowering plants. Some common examples of angiosperms include sunflowers, dogwood trees, elm trees, lilies, and maple trees.Being that angiosperms are a very large group of plants, with over 250,000 known species, they are often further classified into monocots and eudicots. Monocots are known for having one original leaf from their seed, parallel veins in their leaves, flower parts in multiples of three, and a fibrous root system.
Eudicots vary from monocots because they have two original leaves from their seed, branched veins, flower parts in multiples of four or five, and a taproot. Monocots and eudicots can also be distinguished from one another based on the arrangement of their vascular vessels. Eudicots have their vascular vessels arranged in a ring towards the outside edge of the plant, while monocots have a more complex arrangement with bundles of vascular vessels spread throughout the entire plant.
Vascular plants come in many different shapes, colors, and sizes. The largest vascular plants in the world are Sierra redwood trees, with the tallest individual tree being around 325 feet tall! Not only are these trees enormous in height, they are also very wide at their base. On average, the base of a Sierra redwood tree is around 30 feet across and 95 feet around.Although having vascular vessels makes it possible for vascular plants to grow very large, some vascular plants prefer to remain small.
The smallest vascular plant is an aquatic plant known as a water-meal. It is about the size of a candy sprinkle and the flowers are so small that they only have one pistil and one stamen. Water-meal is commonly found floating on the surface of lakes and marshes.
From microscopic flowers to towering trees, vascular plants are a diverse and interesting group of plants. Their vascular vessels used to transport food and water set them apart from other types of plants.
Due to the large number of plants in this group they are often organized by how they reproduce, including creating spores, seeds within cones, and seeds within flowers or fruits. The wide diversity of vascular plants makes it possible for each environment to have a unique look even when most of the plants have the same basic design.
After reading or viewing this lesson, put your knowledge to the test:
- Describe the purpose of vascular vessels
- Discuss the two types of vascular vessels
- Give an example of an angiosperm and a gymnosperm
- Compare and contrast eudicots and monocots