Vascular Plants

• Structure of Plant Categories, courtesy emc.maricopa.edu
  
  Vascular plants have an intricate system of veins that transport water, minerals, nutrients and sugars through the plant structure. These plants have roots, stems, often branches, and sometimes bark. The stems and veins of vascular plants allow them to grow much larger than other types of plants, so most plants we notice, such as trees, shrubs and flowering plants, are vascular in structure. Their system of nutrient transportation also allows vascular plants to create sophisticated methods of reproduction with the energy they have left over.
  
  

Seed-bearing Vascular Plants

• Most vascular plants produce sexually: that is, they create seeds and pollen containing the female and male parts of the plant species. Pollen is distributed, usually by air, so that it can fertilize seeds that are in turn distributed to grow into new plants. Many seeds, known as fruits, develop protective or nutritious shells while still on the parent plant. Other seeds are kept in cones or distributed on the wind like pollen. Only vascular plants that reproduce in this manner create flowers.
  
  

Non seed-bearing Vascular Plants

• There is also a group of vascular plants that produce without seeds. Ferns are the most common type of plant found in this category. Although ferns have roots and a vascular system, they grow fronds instead of leaves and reproduce with spores in a manner more similar to mold and fungus reproduction. Spores are a type of asexual reproduction, in which a copy of the parent plant grows from a small storage system containing all necessary genetic information. In ferns, spores are produced and released from the undersides of their fronds.
  
  

Non vascular Plants

• Non vascular plants do not have root structures or vein systems. Plants in this category include mosses, liverworts, hornworts and some algae (although algae is usually considered a separate organism because of its simplified structure). These plants do use photosynthesis to convert sunlight into energy, but their lifespan and processes differ drastically from vascular plants. Their lack of veins inhibits their growing ability, which is why mosses and liverworts are small and stay close to the surface of the earth.
  
  

Non vascular Reproduction

• Non vascular plants rarely produce spores. If they produce asexually at all, it is through regeneration of plant structures, which allow new plants to form from broken-off parts of the original specimen. Sexual reproduction is the more common method. Sperm cells are developed in one part of the plant, and an egg is produced in another. If enough moisture is present, the sperm cells can migrated over to egg cells and fertilize them. This does not mean non vascular plants have to live underwater--usually, a layer of dew is enough for them to reproduce.