Types of Plants: The Four Major Classifications of Plants

Types of Plants

Types of Plants: Plants are all unique in terms of physical appearance, structure, and physiological behavior. Aside from that, they also vary in their habitats, tolerance, and nutrient requirement.

So with that kind of diversity, the big question is, how do you exactly start to classify them? Good thing botanists have already devised ways in order to classify them. In fact, classifying plants is considered as one of the oldest approaches in studying botany.

In general, scientists group plants into two major groups: non-vascular and vascular. The former being composed of early plants while the latter consists of plants which had developed a vascular system.

However, this kind of grouping seems to be very general and covers a wide variety of scope. The more commonly used classification is the more specific one: by classifying them into different phyla.

Types of Plants

Plant Kingdom Classifications

Non-vascular Plants

As their name implies, nonvascular plants[1] lack vascular tissues that can help them transport water and nutrients. Nonvascular plants are considered to be the earliest living plants in the planet. However, fossils have not been found because these types of plants fossilized poorly. The most common non-vascular plants include the members of the Phylum Bryophyta and is described below.

Bryophytes

Bryophytes - Moss plants in Iceland
Bryophytes – Moss plants in Iceland
The Phylum Bryophyta[2], are the most diverse group with more than 10,000 plant species. This phylum include the mosses, liverworts, and hornworts.

  • Among all plant phyla, the members of the Phylum Bryophyta are considered as the simplest. In terms of physical appearance, mosses are small and inconspicuous. Basically,bryophytes lack vascular tissue and wood that can render them structural support. They also lack true leaves, stem, and roots that can help them transport water and nutrients. Because of this, they are limited to a narrow range of habitats.
  • Despite lacking some some essential plant organs, bryophytes play an important role in minimizing erosion along bodies of water, carrying out water and nutrient cycling in forests, and regulating temperature in permafrosts. Also see the biological weathering article.
  • In terms of habitats and physical structures, bryophytes are related to lichens[3] (symbiotic relationship between a fungus and an algae). For instance, both of them utilize the moisture in the environment in order to transport minerals and nutrients.
  • Because of that, bryophytes live in moist places and somehow have adapted several methods that can help them thrive in dry periods.
  • Bryophytes reproduce through spores. Check out the life cycle of Bryophytes in detail here.
  • At present, the classification of some species of bryophytes still remains arbitrary and is up for further studies.

Bryophyte Examples

  • Mosses

    Mosses
  • Liverworts

    Liverworts
  • Hornworts

    Hornworts

Vascular Plants

Also known as the tracheophytes, vascular plants have been allowed by evolution to posses vascular tissues (xylem and phloem) that aid them to transport water and minerals. All other plants like the members of the Phylum Pteridophyta, Gymnosperms, and Angiosperms are classified as vascular plants. The said plant phyla are described below.

Pteridophytes

Pteridophytes Plants The next phylum in this list is the Phylum Pteridophyta which is composed of almost 12,000 (with over two-thirds are tropical) species of true ferns and fern allies.

  • Pteridophytes[4] are seedless plants; being such, they are incapable of passing on their genetic material to their offspring using cones, fruits, or seeds. Instead, these group of plants produce spores that are located on the underside of their leaves known as sporophylls.
  • Pteridophytes are able to catapult their spores even at long distances because of the spring-like structures of these sporangia-containing spores.
  • In terms of physical appearance, pteridophytes[5] are extremely diverse and there is no single characteristic that can describe them. Leaves of ferns are called fronds, which typically are coiled until they unroll at maturity. They also have horizontal stems called rhizomes and have simple leaves roots. Unlike bryophytes, they are already vascular plants and capable of transporting fluids.
  • Through time, pteridophytes have already adapted to a wide range of habitat: they can be aquatic, terrestrial, and even cold-resistant, but most of them still prefer to thrive in tropical regions. See the life cycle of Pteridophytes in detail here.

Pteridophyte Examples

  • Salvinia Natans

    Salvinia Natans
  • Horsetail

    Horsetail
  • Fern

    Fern

Gymnosperms

Gymnosperm plants Gymnosperms[6], as compared with other plant phyla, include the tallest, the thickest, and the oldest living plants. They are widely distributed in the planet but dominate the temperate and arctic regions.

  • Members of this phylum include pines, hemlocks, firs, and spruces, which all are characterized by having wood, and green needle-like or scale-like foliage.
  • The name “gymnosperm[7]” literally means “naked seed“, which is exhibited by the members by having cones (or strobilus, plural: strobili) instead of seeds to reproduce.
  • Gymnosperms are considered to be heterosporous. This means that they produce two distinct types of cones for the male and female. Usually, male cones are smaller as compared to the large cone of the female.
  • In relation to what was alluded above, gymnosperms are good sources of wood and paper. Aside from that, they provide food and habitat for animals, and in return, these animals become important in the dispersal of their propagules.

Gymnosperm Examples

  • Giant Sequioa Tree

    Giant Sequioa Tree
  • Sago Palm

    Sago Palm
  • Maidenhair Tree

    Maidenhair Tree

Angiosperms

Angiosperm Plants Angiosperms[8], also referred to as the flowering plants, are the most diverse plant phylum with at least 260,000 living plant species.

  • Angiosperms display a vast diversity of plants as they include trees, herbs, shrubs, bulbs, epiphytes (parasitic plants), and plants living in both marine and freshwater habitats.
  • The largest families in this phylum are the Orchidaceae (family of orchids), Asteraceae (family of daisies), and Fabaceae (family of legumes).
  • Despite their diversity, this phylum is united by several distinguishing characteristics:
    1. ovules/seeds that are enclosed within the carpel/fruit.
    2. double fertilization, which is the process that leads to the formation of the nutritive tissue called the endosperm.
    3. male reproductive tissue composed of two pairs of pollen sacs, and many more. Refer to life cycle of angiosperms in detail here.
  • The oldest known angiosperms were a group of plants known as the magnoliids, which are composed of small inconspicuous flowering plants. Scientists think that this group gave rise to the monocots and eudicots.
  • Because of their many types, angiosperms offer a wide variety of uses for animals, especially humans. Most angiosperms are good sources of food, medicine, clothing fibers, and wood. Check out 25 most beautiful purple flowers and their classifications.

Angiosperm Examples

  • Water Lily

    Water Lily
  • Cosmos Flower

    Cosmos Flower
  • Sunflower

    Sunflower

Did you find this way of classifying plants effective? Are there any other ways you might have classified the types of plants?

Cite this article as: "Types of Plants: The Four Major Classifications of Plants," in Bio Explorer, March 11, 2017, http://www.bioexplorer.net/types-of-plants.html/.

References

  • [1]“Evolution of Plants – Biology Encyclopedia – cells, body, human, process, system, different, organisms, life, structure”. Accessed March 11, 2017. Link.
  • [2]“Introduction to the Bryophyta”. Accessed March 11, 2017. Link.
  • [3]“Phylum Bryophyta”. Accessed March 11, 2017. Link.
  • [4]“Phylum Pteridophyta: Characteristics, Classification & Life Cycle – Video & Lesson Transcript | Study.com”. Accessed March 11, 2017. Link.
  • [5]“Phylum Pterophyta: Ferns”. Accessed March 11, 2017. Link.
  • [6]“Gymnosperms”. Accessed March 11, 2017. Link.
  • [7]“Gymnosperm – New World Encyclopedia”. Accessed March 11, 2017. Link.
  • [8]“Angiosperms (Flowering plants) — The Plant List”. Accessed March 11, 2017. Link.
Types of Plants: The Four Major Classifications of Plants
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