Types of Plants: Plants are all unique regarding 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 to classify them. In fact, classifying plants is considered as one of the oldest approaches in studying botany.
In general, botanists 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 plant classification is the more specific one: by classifying them into different phyla.
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Types of Plants
The first classification of plants is the non-vascular plants; As their name implies, nonvascular plants 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.
- Among all plant phyla, the members of the Phylum Bryophyta are considered the simplest. Regarding physical appearance, mosses are small and inconspicuous. Bryophytes lack vascular tissue and wood that can render them structural support. They also lack true leaves, stems, 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 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 permafrost. Also see the biological weathering article.
- Regarding habitats and physical structures, bryophytes are related to lichens (symbiotic relationship between a fungus and algae). For instance, both of them utilize the moisture in the environment 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 remains arbitrary and is up for further studies.
Also the next classification of plants is also known as the tracheophytes, vascular plants have been allowed by evolution to possess 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 are seedless plants; being such, they are incapable of passing on their genetic material to their offspring using cones, fruits, or seeds. Instead, this classification of plants produces spores that are located on the underside of their leaves, known as sporophylls.
- Pteridophytes can catapult their spores even at long distances because of the spring-like structures of these sporangia-containing spores.
- Regarding physical appearance, pteridophytes are extremely diverse, and no single characteristic 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.
- 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” 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.
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- 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:
- 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.
Did you find this way of classifying plants effective? Are there any other ways you might have classified the types of plants?