Gymnosperms are a group of seed-bearing plants that do not produce flowers or fruits. Gymnosperms are not surrounded by fruit. They are believed to have first appeared during the Carboniferous period and became the dominant land plants during the Mesozoic era. In this article, we will cover gymnosperm notes, their classification, characteristics, and more.

What are Gymnosperms?

Gymnosperm lack flowers and fruits, which are typical features of angiosperms. Gymnosperm word originates from the Greek language (gymnos-naked; Sperma-seed) i.e., Naked Seed. Gymnosperms plants produce the seed but without fruits like in angiosperms. One of the characteristics of gymnosperms is their seeds, which are typically exposed on the surface of cones or in a naked condition. This is in contrast to angiosperms (flowering plants), which enclose their seeds within fruits. Gymnosperms also have vascular tissue that transports water and nutrients throughout the plant and typically has needles or scales as leaves.

Gymnosperms

Gymnosperms is a subtype of the Plant Kingdom, and the subkingdom is Embryophyta. Some fossil records give evidence that the gymnosperm is evolve in the Paleozoic era, around 390 million years ago. The gymnosperm plant ovule is not closed and it remains open whereas the angiosperm ovule is covered with ovary. To decrease the transpiration rate gymnosperm plant leaves are need-like, sunken stomata over the leaf. 

Characteristics of Gymnosperms

Mentioned below are the characteristics of gymnosperm:

• They are the most primitive and simple seed plants.
• The seeds produced by these plants are naked and are not enclosed within fruits.
• Usually perennial, evergreen, and woody plants, are present in colder areas.
• Gymnosperms usually have needle-like leaves.
• Sporophylls are aggregated to form cones. These are separate male and female cones.
• Xylem lacks vessels and the phloem lacks companion cells.
• The plant body is saprophytic and is differentiated into roots, stems, and leaves.
• Leaves are generally spirally arranged. They may be whorled as in Cedrus or opposite and decussate as in Gnetum.
• Vegetative methods of reproduction are rare in gymnosperms. Cycads do propagate through bulbils.
• Pollination is direct i.e., pollen grains come in contact in direct contact with the ovule.
• All gymnosperms are wind-pollinated because stigma is absent in gymnosperms.
• The number of cotyledons in a seed is one or two as in Cycas or many as in Pinus.

Classification of Gymnosperms

Gymnosperms are classified into 4 types. Each group is distinguished by its unique characteristics, and they all play important ecological roles in their respective habitats, those are:

Cycadophyta

Cycads are dioecious (meaning: individual plants are either all male or female). Cycads are seed-bearing plants and most of the individuals are presently extinct. They grow during the Jurassic and late Triassic times. These days, plants are considered relics from past times. 

Cycadophyta

These gymnosperms plants generally have big compound leaves, thick trunks, and little pamphlets which are connected to a central stem. They range in level from any place between some centimeters to a few meters. Cycads are generally seen in the tropics and subtropics region. Some Cycadophyta is adapted to dry conditions and some likewise have adjusted to oxygen-poor damp conditions. Examples: Cycas, Zamia, Zamiaceae.

Ginkgophyta

Only one, Ginkgophyta is a living animal group. Any remaining individuals from this class are extinct. The Ginkgo trees are described by their big size and their fan-like leaves. Likewise, Ginkgo trees have an enormous number of uses going from medication to cooking. Ginkgo leaves are ingested as a solution for memory-related diseases like Alzheimer’s. 

Ginkgophyta

Gnetophyta

Gnetophytes are additionally relics from an earlier time. Today, just three individuals from this family exist. Gnetophytes typically comprise tropical plants, trees, and shrubs. They show the phenotype of colorful leaves that are covered with a soft coating. This cover tells a hereditary association with angiosperms. Gnetophytes vary from different individuals from this class as they have vessel components in their xylem. Example: Ephedra, Gnetum.

Gnetophyta

Coniferophyta

These are the most ordinarily known species among the gymnosperm family. They are evergreen; consequently, in winters they don’t shed their leaves. These are essentially described by male and female cones with structures like a needle. Coniferous trees are normally found in temperate zones where the typical temperature is 10 ℃. Monster sequoia, pines, cedar, and redwood are instances of Conifers. Examples: redwood trees, junipers, cypress trees, tidy trees, and hemlocks.

Coniferophyta

Gymnosperms Example

Some examples of gymnosperms are:

• Pinus
• Araucaria
• Cycas
• Picea
• Thuja
• Cedrus
• Larix
• Abies

Gymnosperm Life Cycle

Gymnosperm plants have both haploid and diploid life cycles that is they reproduce via generation alteration. The life cycle of gymnosperms involves a complex process of alternation between two generations, the sporophyte, and the gametophyte. Gymnosperm have sporophyte-dominant life cycle.

Gymnosperms are heterosporous plants i.e., plants produce spores that are haploid microspores or megaspores. The gametic phase of the gymnosperm is short. Reproduyctive organ of gymnosperms are:

• Male Cones: The male cones of gymnosperms develop from the sporophyte. They contain the male gametophyte, which produces pollen grain. Microsporangium forms microspores that are haploid in structure, some microspheres develop into pollen grains and others degrade.
• Female Cones: The female cones of gymnosperms develop from the megasporophylls. Megasporangium contains the female ovule, which produces megaspores.

Once the pollen reaches the female cones via wind or any pollinating agent, it fertilizes the eggs, resulting in the formation of a diploid zygote. The zygote develops into an embryo, which is enclosed in a seed. The seed is then dispersed and can grow into a new sporophyte plant. 

The life cycle of gymnosperms is different from that of angiosperms because gymnosperms do not produce flowers or fruits. Instead, they produce cones and seeds that are usually exposed. The life cycle of gymnosperms is an essential process that ensures the continued growth and reproduction of these plants.

Economic Importance of Gymnosperms

The economic importance of gymnosperms are:

• Timber: Gymnosperms, such as pines, firs, and spruces, are valuable sources of timber for construction, furniture, and paper production.
• Paper Production: Gymnosperm wood pulp is used in the papermaking industry.
• Resin: Some gymnosperms, like pines, produce resin, which is used in various products such as varnishes, adhesives, and pharmaceuticals.
• Ornamental Plants: Certain gymnosperms, like cedars and junipers, are cultivated for their ornamental value in landscaping and gardens.
• Medicinal Uses: Extracts from certain gymnosperms have medicinal properties and are used in traditional medicine for treating various ailments.

Also Read: Economic Importance of Gymnosperms

Gymnosperms and Angiosperms Difference

The major difference between Gymnosperms and Angiosperms are: