What are vascular plants? They are plants that have developed specialized tissue (called a vascular structure) to transport water and nutrients. They are also called the "higher plants" and include everything from conifer trees to flowering plants to ferns. While some of these grow seeds, such as conifers and flowering plants, some do not, like ferns. The seedless vascular plants are in four plant divisions that you may never have heard of before: psilophyta, lycophyta, sphenophyta and pterophyta. However, you will find that you are familiar with the common names of many of the seedless vascular plants.
Vascular Plants Characteristics
Vascular plants are plants that have a specialized tissue structure that they use to transport nutrients and water between different areas of the plant. This allows plants to stand upright and grow tall. Don't think of this as a small, little-known segment of the plant kingdom. Some 90 percent of all plants are in the vascular plant category. Trees, shrubs, flowers, grasses and vines are all vascular plants.
Groups of Vascular Plants
There are three different groups of vascular plants. They are seedless vascular plants, like clubmosses and horsetails, naked-seed vascular plants, like conifers and ginkos and protected-seed vascular plants, including flowering plants, all grasses and deciduous trees. Naked-seed vascular plants are also called gymnosperms, while protected-seed vascular plants are called angiosperms.
All vascular plants have roots. These are tissues that grow downward from the stem to anchor the plant in the soil and upload nutrients and water into the plant system. Vascular plants also have xylem tissue that moves water throughout the plant stem and foliage. The equivalent tissue that moves nutrients and minerals is called the phloem. The phloem brings food from the roots and transports sugars down through the plant.
Seedless Vascular Plants
Seedless vascular plants include ferns, horsetails and clubmosses. These types of plants have the same special tissue to move water and food through their stems and foliage, like other vascular plants, but they don't produce flowers or seeds. Instead of seeds, seedless vascular plants reproduce with spores.
Spores are very lightweight, which helps them disperse quickly in the wind. This allows plants like ferns to spread easily to new areas. Seedless vascular plants depend on water during fertilization, since the sperm must swim to get to the egg. This explains why ferns and other seedless vascular plants are found most often in marshes, swamps, humid areas and rainforests.
If you look closely at the life cycle of a fern, you find that every other generation has a dominant sporophyte stage, while the others have a haploid gametophyte phase. This is an independent but inconspicuous organism. The dominant phase is the diploid sporophyte.