Cones and seeds are developed by Gymnosperms, which are flowerless plants. Gymnosperm seeds are referred to as “bare seeds” since they are not housed within an ovary. Instead, they are placed on the surface of bracts, which are leaf-like structures. Conifers, cycads, ginkgoes, and gnetophytes are instances of gymnosperms, which are vascular plants belonging to the Embyophyta subkingdom.

Gymnosperms Definition

“Gymnosperms are seedless seeded plants that developed before flowering plants. Their seeds are visible on the megasporophylls or carpels. They are most likely the first surviving seed plants.”

Gymnosperm comes from a combination of two Greek words: “gymnos” means “naked,” and “Sperma” means “seed,” making it literally “naked seed.”

The woody cones of the pine tree add to its appeal and familiarity, yet many of us are unaware that pine trees and other conifers are gymnosperms. It’s also possible that people believe gymnosperms are only made up of conifers. Among seed plants, the massive flowered angiosperms are probably more well-known, but Gymnosperms are equally worth exploring. The gymnosperm is assumed to have first appeared during the late Carboniferous epoch. Gymnosperms are the result of a genome duplication that took place millions of years ago.

Gymnosperms are divided into four primary categories, each of which is generally regarded as its phylum: Cycadophyta, Ginkgophyta, Gnetophyta, and Pinophyta. 

Gymnosperms Characteristics

Gymnosperms are seed-producing plants, but unlike angiosperms, they do not produce fruits. With less than 900 species, they constitute a small group of plants. Gymnosperm factors are listed:

Occurrence

Gymnosperms can be found all over the world. The majority of them may be found in the northern hemisphere’s temperate and subarctic zones.

 Size

Gymnosperms are trees that are tall and perennial. Zamia pygmaea is the smallest gymnosperm, and Sequoia sempervirens is the highest. Gnetum ula is a climber which prefers to be in the woods.

Plant body

The root, stem, and leaves make up the sporophyte plant body.

Habit

Gymnosperms are mostly woody, evergreen plants. Gymnosperms are mostly trees and shrubs. Some of them may be lianas or climbers.

Roots

They have a fibrous root system, often referred to as a taproot system.

Stems

They have erect stems since they are woody plants. Gymnosperm stems are either unbranched or heavily branched.

Leaves

Simple, needle-like leaves (Pinus, Juniper, etc.) or compound leaves (palms) are common. With a thick cuticle (Cycas).

Xylem

The xylem transports water and minerals throughout the plant while also providing support. The xylem of gymnosperms is devoid of vessels. In the secondary wood, Gnetum contains vessels.

 Phloem

Companion cells are lacking in the phloem in the majority of cases, according to the sieve tube. Rather, sieve cells are used to transport food. In pine, albuminous cells have taken the position of partner cells.

Flower

Flowers are not generated by them.

Seeds

Gymnosperm seeds are naked and borne in cones that are not visible until maturity.

Classification of Gymnosperms

As per Kramer and Green, the Gymnosperms are further split into four classes (See Kubitzki, 1990). Gymnosperms are divided into four groups:

Cycadopsia

1. Both fossil and live members are used to symbolise them. They were first discovered during the Triassic epoch. Many of them can be found in tropical environments.
2. They have a woody, dioecious appearance (separate male and female plants).
3. At the summit of the plant, they have a single, usually unbranched trunk. On top of the trunk, the leaves are borne together.
4. Cycad cones are enormous, with many fertile leaves organised into cones, similar to sporophylls.
5. Because of their attractive shape, they are widely applied as ornamental plants.
6. Cycas and Zamia are two instances.

Ginkgopsida

1. Because Ginkgo biloba is the only living species in this class, it is commonly referred to as a living fossil; all other species are extinct.
2. Their leaves are fan-shaped and have dichotomous venation.
3. They have a dioecious nature. Male or female cones are produced by individual plants.

Ginkgo biloba is a fine example.

Coniferopsida

1. The most common and prominent gymnosperms are evergreen and tall gymnosperms.
2. The leaves are needle- shaped.
3. Adapted to drier climates and found at higher elevations.
4. A stem is surrounded by sporophylls.
5. Cones are often woody, but can also be soft and mushy.
6. They have two sexes.

Cedrus, Spruce, and Firs, for instance.

Gnetopsida

1. They consist of shrubs and tiny trees.
2. Gnetum has angiosperm-like exterior and internal properties.
3. Their reproductive structures resemble flowering plants in appearance.
4. Female reproductive organs are carried in whorls or inflorescence.
5. The xylem contains vessels.
6. Gnetum and Ephedra are two instances.

Gymnosperms Life Cycle

(a) Gymnosperms exhibit generational alternation.

(b) The life cycle is dominated by the formation of diploid photosynthetic sporophytes.

(c) The sporophyte and haploid are required for gametophytic generation.

Examples of Gymnosperms Plants

Gymnosperm plants include the following:

• Cycas
• Pinus
• Ginkgo
• Gnetum
• Ephedra
• Juniperus
• Spruce
• Abies
• Cedrus
• Thuja

Smallest gymnosperm

Zamia pygmaea is the world’s smallest live cycad and (probably) gymnosperm, growing no more than 10 inches tall. This plant is only found in Cuba and is described by a variety of names, including “guayaro,” “guayra,” and “guayra.”.

Gymnosperm tree

Gymnosperms are a type of woody plant that includes shrubs, trees, and vines (some gnetophytes). Their seeds are not trapped in an ovary like those of blooming plants and are therefore exposed to a variety of structures, the most well-known of which are cones.

Gymnosperms Importance

Gymnosperms are important for both ecological and economic reasons:

Ecological Importance

Gymnosperms are a wonderful source of food and a great place for animals to live. Pinus gerardiana is a food tree.

Gymnosperm plants help to keep soil from eroding.

Gymnosperms generate a lot of oxygen, which helps to decrease greenhouse gas emissions.

Economic Importance

• Paper pulp, lumber, turpentine, and resins are all made from Gymnosperms. Paper pulp is made from Pinus roxburghii.
• Gymnosperms are a fuel source.
• Gymnosperms are employed in the field of pharmaceuticals. Asthma and bronchitis are treated with Ephedra gerardiana.
• Gymnosperms produce a lot of wood, which can be used to make furniture and other structures. Doors, boats, and railway sleepers are all made from Cedrus deodar.
• Gymnosperm plants are sometimes employed as ornaments and decorations.
• Taxus baccata is used to make Taxol, an anti-cancer medication.

Conclusion

Gymnosperms are ancient plants that have been around for millions of years, as per this article. They are said to be the first plant to produce seeds. They do not, meanwhile, produce blooms or fruits; instead, their seeds are referred to as naked seeds because they lack an exterior coating or shell. The majority of these plants may be found in tropical climates. The world’s tiniest live cycad and (possibly) gymnosperm, Zamia pygmaea, grows no more than 10 inches tall. The name “guayaro,” “guayra,” and “guayra” are all used to designate this shrub, which is solely found in Cuba.