Gymnosperms: Features and Characteristics

“Gymnosperm” is derived from the Greek terms “gymnos” meaning naked, and “Sperma” meaning seed, so “Naked seeds.” The Gymnosperms belong to the group Spermatophyta, which includes flowering plants and Angiosperms. Ovuliferous scales, which are not contained in carpels, bear exposed ovules on flat scale leaves called Gymnospermae (ovary). Cones are formed by the ovuliferous scales.

These plants generate a cone-like structure on the surface of scales or leaves, or at the end of stalks. Gymnosperms are members of the Plantae kingdom and the subkingdom Embryophyta. They are thought to have developed some 390 million years ago, i.e., during the Paleozoic era.

Gymnosperms have the following key features:

1. Gymnosperms are non-flowering plants that belong to the Embryophytes sub-kingdom
2. An ovary or fruit does not encapsulate the seeds. They can be located on the surface of gymnosperms’ leaf-like structures
3. Cycadophyta, Coniferophyta, Ginkgophyta and Gnetophyta are the four classes of plants
4. Gymnosperms can be present in temperate and boreal woods

Gymnosperm Characteristics:

1. The adult plant, which is called sporophyte, is a tall, woody perennial tree or shrub that is mostly evergreen in appearance
2. The stem is normally branching, although in some cases, such as in Cycas, it is unbranched
3. There are two types of leaves: simple and complex
4. Leaves can be dimorphic or monomorphic. The foliage leaves of Pinus and Cycas are enormous green, plain or pinnately compound, needle-like, and grow on the dwarf branch or straight on the primary trunk. Scale leaves are basic and brown
5. Secondary growth is visible in the stem’s vascular bundles, which are organized in a circle
6. Gymnosperms have cones that are normally unisexual, meaning either male or female, with the exception of Gnetum, which is bisexual
7. Pollen grains are haploid and generated in male cone microsporangia. Each pollen grain in Pinus has two enormous sacs called wings that aid in wind dissemination. The pollen grains produce two male gametes
8. Gymnosperms are known as “naked seeds” because their ovules are not encased in the ovary as they are in Angiosperms but instead are carried barely on the female cone’s leafy megasporophylls. Ovules are created alongside each other, each containing a female gamete or egg. In the ovule, the male gamete combines with the female gamete. After fertilisation, the ovule grows into a seed, winged in the case of Pinus

Gymnosperm classification

Cycadophyta:

• It is a dioecious genus of cycads, which means the individual plants are either all male or female

• Cycads are seed-bearing plants that have become extinct in the largest of their species. During the Jurassic and late Triassic periods, they thrived. Plants are now regarded as pieces of history

• Large compound leaves, robust trunks, and little leaflets linked to a single central stem characterize these plants. They can be anything from a few centimeters to many meters tall

• The tropics and subtropics are where you’ll find cycads. Some individuals have acclimated to dry, arid surroundings, while others have evolved to marshy, oxygen-poor habitats

Ginkgophyta

• Ginkgophyta, another Gymnosperm class, has just a single extant species. This class’s other members have become extinct

• The Ginkgo tree is distinguished by its huge size and fan-like leaves. Ginkgo trees also have a variety of uses, ranging from culinary to medicine. Ginkgo leaves are used to treat cognitive impairments such as Alzheimer’s disease

• Ginkgo trees are also extremely resistant to pollutants, as well as illnesses and parasitic insects. In fact, six Ginkgo trees have been the only living beings to remain within a kilometer or two of the blast radius after the nuclear bombs were dropped on Hiroshima

Gnetophyta

• Gnetophytes, like the rest of the gymnosperm family, are remnants of the past. Today, there are only three species of this genus left

• Tropical plants, trees, and shrubs make up the majority of gnetophytes. They are distinguished by their softly coated floral leaves. This coating suggests a phylogenetic relationship with angiosperms

• Gnetophytes vary from other members of this class because their xylem contains vessel components

Coniferophyta

• Among many of the types of gymnosperms, these are the most well-known species

• They are evergreen; thus, their leaves do not fall off in the winter. Male and female cones that produce needle-like formations are the most distinguishing features

• Coniferous trees grow best in temperate climates having temperatures of 10 degrees Celsius

• Conifers include giant sequoia, pines, cedar, and redwood

Examples:

Cedar- Cedrus, Pine- Pinus, Juniper- Juniperus, Redwood- Sequoia, and Sago’s palm- Cycas are gymnosperms examples.

Uses:

• Timber, resins, turpentine, and a variety of other goods are produced by gymnosperms, including the dried fruit chilgoza
• The aged stems of Cycas are used to make sago, also known as sabudana