Dive into the fascinating world of Pteridophyta, the diverse group of vascular plants commonly known as ferns and their allies. This comprehensive guide will explore:
- General characteristics of Pteridophyta
- Classification of fern groups
- Early land plants: Cooksonia and Rhynia
- In-depth study of key genera:
- Evolutionary insights:
- Ecological significance of Pteridophytes
- Economic importance and applications
Discover the morphology, anatomy, and reproductive strategies of these ancient plants. Uncover their role in ecosystems and learn about their practical uses in today’s world. Whether you’re a botany student, researcher, or nature enthusiast, this article provides essential knowledge about these remarkable plants.
What is Pteridophyta?
- Pteridophyta, commonly known as pteridophytes, are vascular plants characterized by the presence of xylem and phloem. These plants reproduce via spores rather than seeds or flowers, earning them the classification of cryptogams—plants with hidden reproductive processes.
- Ferns, horsetails, and lycophytes fall under the pteridophyte category. Although these groups share similarities, they do not form a monophyletic group. This means ferns and horsetails are more closely related to seed plants than they are to lycophytes. As a result, “Pteridophyta” is no longer a widely accepted taxonomic group, yet the term “pteridophyte” remains prevalent in botanical discussions and studies.
- The term pteridophyte originates from Greek, where “pteron” means feather, and “phyton” means plant. Ernst Hackel coined this term due to the feather-like appearance of their fronds. Pteridophytes are considered one of the most primitive groups of seedless vascular plants. They lack flowers, fruits, and seeds, relying solely on spores for reproduction. This unique reproductive strategy, dependent on water for fertilization, parallels the life cycle of bryophytes, thus earning them the nickname “amphibians of the plant kingdom.”
- Pteridophytes are also referred to as “Botanical Snakes” or “Snakes of the Plant Kingdom.” This metaphor highlights their ancient and somewhat mysterious nature in the plant world. Despite their primitive status, pteridophytes play a crucial role in understanding plant evolution and the transition from aquatic to terrestrial life forms.
Habitat of Pteridophyta
Pteridophyta, commonly known as pteridophytes, have specific habitat preferences that reflect their evolutionary adaptations and ecological requirements. Below is a detailed explanation of their habitat characteristics:
- Shady Environments:
- Pteridophytes are often found in areas with limited direct sunlight. Forest understories provide the ideal conditions with dappled light and protection from intense sun exposure. The shade helps maintain the moisture levels essential for their survival.
- Damp Locations:
- Moisture is crucial for the growth and reproduction of pteridophytes. They thrive in damp environments such as riverbanks, wetlands, and areas near streams or waterfalls. The high humidity in these locations supports their need for water, especially during the fertilization process.
- Forests and Woodlands:
- Dense forests and woodlands offer an optimal habitat for pteridophytes. These areas provide a consistent microclimate with stable humidity and temperature, protecting the plants from extreme environmental conditions.
- Tropical and Subtropical Regions:
- Pteridophytes are commonly found in tropical and subtropical regions where the climate is warm and humid year-round. The consistent moisture and warmth in these regions create ideal conditions for their growth and reproduction.
- Temperate Zones:
- While less common, some pteridophytes also inhabit temperate zones. In these regions, they are often found in microhabitats that mimic the conditions of their tropical counterparts, such as shaded ravines, moist woodlands, and sheltered valleys.
- Rock Crevices and Cliff Faces:
- Certain pteridophytes are adapted to grow in rock crevices and on cliff faces. These locations provide the necessary shade and moisture retention while offering protection from herbivores and competition from other plants.
- Swampy and Marshy Areas:
- Swamps, marshes, and bogs are also favorable habitats. These wetland areas provide the constant water supply needed for the lifecycle of pteridophytes, from spore germination to gametophyte development and fertilization.
- Garden and Cultivated Settings:
- In addition to natural habitats, pteridophytes are often found in botanical gardens and cultivated landscapes. These settings replicate their natural environments with controlled humidity, shade, and soil conditions.
Characteristics of Pteridophyta
Pteridophyta, commonly known as pteridophytes, exhibit several distinctive characteristics that differentiate them from other plant groups. Below are the general characteristics of Pteridophyta:
- Habitat:
- Pteridophytes primarily thrive in shady or damp environments. They are commonly found in forests and moist areas where humidity is high.
- Plant Body Structure:
- The plant body is differentiated into true roots, stems, and leaves. This differentiation allows for efficient nutrient and water absorption, transport, and photosynthesis.
- Vascular System:
- Pteridophytes possess a well-developed vascular system composed of xylem and phloem. This system facilitates the conduction of water, nutrients, and other essential substances throughout the plant body.
- Reproduction:
- These plants reproduce through spores, as they do not produce flowers or seeds. The reproductive organs are multicellular, with male organs known as antheridia and female organs called archegonia.
- Sporangia and Sporophylls:
- Spores develop within structures called sporangia, which are often grouped on specialized leaves known as sporophylls. These sporophylls sometimes curl inward to protect the developing spores.
- Alternation of Generations:
- Diversity in Form:
- There is considerable variation in the form, size, and habit of pteridophytes. They range from small, delicate annuals to large, tree-like perennials.
- Evolutionary Significance:
- Pteridophytes are considered some of the first plants to have evolved on land. Their adaptation to terrestrial life marked a significant evolutionary step from aquatic to land-based plant life.
- Cryptogamic Nature:
- As cryptogams, pteridophytes reproduce through spores, which are often hidden and not produced in visible flowers. This cryptic reproduction method gives them their name.
- Water Dependence:
- Water is essential for the fertilization process in pteridophytes. The male gametes (sperm) require a water medium to reach the female gametes (eggs).
Classification of Pteridophyta
Pteridophytes, are classified into four main classes based on their distinct characteristics and evolutionary traits. These classes are Psilopsida, Lycopsida, Sphenopsida, and Pteropsida.
1. Psilopsida
- Primitive Nature:
- Psilopsida represents the most primitive class of pteridophytes. Many of its members are now known only as fossils.
- Morphology:
- The plants in this class lack true leaves but possess rhizoids. Their stems are photosynthetic and exhibit dichotomous branching.
- Reproduction:
- Psilopsida are homosporous, producing one type of spore within structures called synangia.
- Examples:
- Psilotum and Tmesipteris are prominent examples of this class.
2. Lycopsida
- Common Name:
- Members of this class are commonly referred to as “club mosses.”
- Plant Body:
- They have a well-differentiated plant body with roots, stems, and leaves. The leaves, known as microphylls, are small and have a single unbranched vein.
- Reproductive Structures:
- Sporophylls, the spore-bearing leaves, form clusters called strobili. Lycopsida can be either homosporous or heterosporous.
- Examples:
- Lycopodium and Selaginella are typical representatives of this class.
3. Sphenopsida
- Common Name:
- Sphenopsida are commonly known as “horsetails.”
- Morphology:
- These plants have a distinct structure with nodes and internodes. Their leaves are microphyllous, arranged in whorls around the stem.
- Reproductive Structures:
- At the tips of fertile branches, sporangia form compact cones known as strobili. Sphenopsida are typically homosporous.
- Examples:
- Equisetum is the most well-known example of this class.
4. Pteropsida
- Common Name:
- This class includes plants commonly known as “ferns.”
- Plant Body:
- Pteropsida have a well-developed plant body with true roots, stems, and large leaves called megaphylls.
- Reproductive Structures:
- Sporangia are clustered on the ventral surface of the sporophylls, forming structures called sori. These plants can be homosporous or heterosporous, and their antherozoids are multiflagellate.
- Examples:
- Common examples include Pteris, Dryopteris, and Adiantum.
Life Cycle of Pteridophyta
The life cycle of Pteridophyta, or pteridophytes, is characterized by a distinct alternation of generations. This cycle involves a dominant diploid sporophytic generation and a short-lived haploid gametophytic generation. The life cycle is haplodiplontic, meaning that both the haploid and diploid phases are almost equally balanced. Each generation is independent and free-living, with specific functions that ensure the continuity of the species.
Sporophytic Generation
- Diploid Phase:
- The dominant phase in pteridophytes is the diploid sporophyte. This phase comprises the main plant body, which is well-developed with roots, stems, and leaves.
- Spore Production:
- The sporophyte produces spores through meiosis. These spores are haploid and serve as the starting point for the next generation.
Gametophytic Generation
- Spore Germination:
- When the spores land in a moist and suitable environment, they germinate into haploid gametophytes. The gametophyte is a small, independent structure known as the prothallus.
- Gametophyte Structure:
- The prothallus bears the sex organs: antheridia (male) and archegonia (female).
- Sex Organ Functions:
- Antheridia produce sperm.
- Archegonia produce eggs.
Fertilization and Zygote Formation
- Water Dependence:
- Pteridophytes require water for fertilization. Sperm swim through a thin film of water to reach the egg in the archegonium.
- Zygote Formation:
- The fusion of sperm and egg results in a diploid zygote. This zygote then develops into a new sporophyte, completing the cycle.
Variations in Gametophyte Sexuality
- Dioicous Gametophytes:
- Individual gametophytes are either male or female. Male gametophytes produce only antheridia, while female gametophytes produce only archegonia.
- Monoicous Gametophytes:
- Each gametophyte can produce both antheridia and archegonia, functioning as both male and female.
- Protandrous Gametophytes:
- Antheridia mature before archegonia. This timing reduces the likelihood of self-fertilization.
- Protogynous Gametophytes:
- Archegonia mature before antheridia, also minimizing self-fertilization and promoting genetic diversity.
Heterospory
Heterospory represents a significant evolutionary adaptation in pteridophytes, where plants produce two distinct types of spores: microspores and megaspores. This division of labor in spore production enhances reproductive efficiency and reduces reliance on water for fertilization.
Definition and Mechanism
- Two Types of Spores
- Microspores: These are smaller spores that develop into male gametophytes. Their primary function is to produce sperm cells.
- Megaspores: These are larger and more nutrient-rich spores that develop into female gametophytes. Their main role is to produce egg cells.
- Production and Dispersal
- Microspores: Formed through meiosis in microsporangia, they are numerous and dispersed widely. Their small size facilitates longer distance dispersal.
- Megaspores: Produced in megasporangia, they are fewer in number and retained close to the parent plant. They provide significant resources to support the developing embryo.
Evolutionary Advantages
- Resource Efficiency
- Specialization: By dividing spore production into microspores and megaspores, plants allocate resources more efficiently. Microspores are numerous but small, reducing resource expenditure on each spore. Megaspores are fewer but large, providing ample nutrition for the developing gametophyte.
- Reduced Waste: This specialization minimizes the waste of resources compared to producing numerous large spores.
- Reduced Dependency on Water
- Gamete Production: The heterosporous life cycle decreases the dependency on water for fertilization. Microspores are adapted for wider dispersal, while megaspores are retained close to the parent plant, reducing the need for water to transport gametes.
- Pollination: In extreme cases, the megaspore remains within the parent plant, waiting for fertilization by a nearby microgametophyte. This adaptation represents an evolutionary step toward pollination and seed development.
Life Cycle of Heterosporous Pteridophytes
- Gamete Formation
- Microgametophyte: Develops from microspores, producing antheridia that generate sperm cells.
- Megagametophyte: Develops from megaspores, producing archegonia that generate egg cells.
- Fertilization
- Sperm cells from the microgametophyte fertilize the egg cells in the megagametophyte, resulting in the formation of a zygote.
- Development of Sporophyte
- The zygote develops into a sporophyte, which then produces two types of sporangia: microsporangia and megasporangia.
- Microsporangia: Undergo meiosis to produce numerous microspores.
- Megasporangia: Undergo meiosis to produce one or a few megaspores.
- Cycle Continuation
- Both types of spores develop into their respective gametophytes, and the cycle continues with new spore production.
Stelar Evolution
Stelar evolution refers to the development and diversification of the central vascular tissue system in plants. The stelar system is crucial for the efficient transport of water, nutrients, and sugars throughout the plant. In pteridophytes, stelar evolution showcases the progression from simple to more complex vascular structures.
- Protostele
- Structure: The protostele is the simplest type of stele, characterized by a central solid core of vascular tissue surrounded by a cortex.
- Occurrence: It is commonly found in early vascular plants, such as certain lycophytes and some primitive pteridophytes.
- Siphonostele
- Structure: The siphonostele features a central pith surrounded by vascular tissue. This structure allows for a more efficient transport system compared to the protostele.
- Occurrence: It is seen in some more advanced pteridophytes, including certain ferns and horsetails.
- Eustele
- Structure: The eustele is characterized by vascular tissue arranged in discrete bundles that are scattered throughout the stem, separated by ground tissue.
- Occurrence: This type of stele is found in some advanced pteridophytes and is a precursor to the complex vascular systems seen in seed plants.
- Evolutionary Trends
- From Simple to Complex: As pteridophytes evolved, there was a trend from simpler stele types, such as the protostele, to more complex structures like the eustele. This progression reflects an adaptation to larger plant sizes and more complex growth forms.
- Increased Efficiency: The evolution of stelar types allowed for improved nutrient and water transport, supporting larger and more diverse plant forms.
Pteridophyta Examples
Pteridophyta, commonly known as ferns and their allies, exhibit a wide variety of species that are classified into different classes based on their unique characteristics. Below are notable examples of Pteridophyta, each representing different genera within the group.
Whisk Fern (Psilotum)
- Characteristics: Whisk ferns are among the most primitive pteridophytes. They have a simple structure with dichotomously branching stems and lack true roots and leaves. Instead, they have rhizoids for anchorage.
- Function: Their stems are photosynthetic, aiding in nutrient absorption and photosynthesis.
- Example: Psilotum.
Club Moss (Lycopodium)
- Characteristics: Known as club mosses, these plants have small, needle-like leaves and reproduce via spores produced in cone-like structures called strobili.
- Function: The small leaves, or microphylls, efficiently conduct photosynthesis and provide structural support.
- Example: Lycopodium.
Spike Moss (Selaginella)
- Characteristics: Selaginella, or spike moss, displays a distinctive branching pattern and often forms dense mats. They are heterosporous, producing two types of spores.
- Function: Their unique branching and spore production allow for efficient reproduction and colonization of damp environments.
- Example: Selaginella.
Horsetail (Equisetum)
- Characteristics: Horsetails have a segmented stem with nodes and internodes, and their leaves are reduced to small scales.
- Function: The segmented stems contain silica, providing rigidity and defense against herbivores.
- Example: Equisetum.
Fern (Pteris)
- Characteristics: Pteris ferns have well-developed fronds (leaves) that are often divided into leaflets. They reproduce via spores produced on the underside of the fronds.
- Function: The large fronds increase photosynthetic efficiency and spore dispersal.
- Example: Pteris.
Shield Fern (Dryopteris)
- Characteristics: Dryopteris ferns are known for their large, shield-shaped fronds. They thrive in moist, shaded environments.
- Function: Their broad fronds facilitate photosynthesis in low-light conditions, while their sori (spore-producing structures) ensure effective reproduction.
- Example: Dryopteris.
Maidenhair Fern (Adiantum)
- Characteristics: Adiantum ferns, or maidenhair ferns, have delicate, fan-shaped fronds with a unique texture and appearance. They prefer humid environments.
- Function: Their fine fronds and high surface area optimize water absorption and photosynthesis.
- Example: Adiantum.
Tree Fern (Dicksonia)
- Characteristics: Dicksonia, commonly known as tree ferns, have a trunk-like stem and large, arching fronds. They are among the largest ferns.
- Function: The trunk elevates the fronds to capture sunlight more effectively, while also providing support for the large leaves.
- Example: Dicksonia.
Man Fern (Cyathea)
- Characteristics: Man ferns, like tree ferns, have a tall, woody trunk and large, divided fronds. They are prominent in tropical and subtropical forests.
- Function: Their structure supports a large canopy, aiding in photosynthesis and spore dispersal.
- Example: Cyathea.
Silver Fern (Pteridium)
- Characteristics: Silver ferns, known for their silvery undersides of fronds, are widespread and can form extensive colonies through underground rhizomes.
- Function: The rhizomes aid in vegetative reproduction, while the fronds perform photosynthesis and spore production.
- Example: Pteridium.
Morphology, Anatomy and Reproduction of Selaginella, Equisetum and Pteris
1. Selaginella
Morphology:
- Habit: Selaginella, commonly known as spike moss, is a small, creeping or trailing plant that often forms dense mats.
- Leaves: The leaves are small, simple, and arranged in four rows along the stem. They are usually lanceolate to ovate, with a single vein.
- Stem: The stem is typically branching, with a distinct, often green, photosynthetic portion.
- Roots: Roots arise from the nodes of the stems and can be adventitious.
Anatomy:
- Vascular System: Selaginella has a protostelic vascular system. The stele is solid and centrally located, consisting of xylem and phloem.
- Leaves: The leaves have a simple vascular system with a central vein. The vascular tissue does not form a continuous cylinder.
- Rhizophore: Special structures called rhizophores arise from the nodes and help in anchoring the plant to the substrate.
Reproduction:
- Sporophyte Generation: Selaginella exhibits heterospory, producing two types of spores: microspores and megaspores.
- Spore Production: The microspores develop into male gametophytes and the megaspores into female gametophytes.
- Gametes Formation: Male gametophytes produce antheridia (sperm), and female gametophytes produce archegonia (egg cells).
- Fertilization: Fertilization occurs when sperm from the male gametophyte reaches the egg in the archegonium of the female gametophyte. This results in the formation of a zygote that develops into a new sporophyte.
2. Equisetum
Morphology:
- Habit: Equisetum, known as horsetail, typically grows in moist, sandy, or marshy environments. It has a distinctive jointed, often ridged appearance.
- Stems: The stems are hollow, jointed, and covered with a sheathing of small, scale-like leaves. The stem is the primary photosynthetic organ.
- Leaves: Leaves are reduced to small, tooth-like structures that are fused into whorls around the stem.
- Roots: Roots are adventitious, arising from the nodes of the underground rhizomes.
Anatomy:
- Vascular System: Equisetum has a siphonostelic structure. The vascular tissue is arranged in a central core surrounded by a pith.
- Stem Structure: The stem has a vascular cylinder with well-developed xylem and phloem. The xylem is often arranged in a star-like pattern.
- Silica Deposition: The cell walls of Equisetum contain high amounts of silica, making them rigid and tough.
Reproduction:
- Sporophyte Generation: Equisetum is homosporous, producing spores that are all of the same type.
- Spore Production: Spores are produced in strobili, which are cone-like structures located at the tips of the fertile stems.
- Gametophyte Formation: The spores germinate into a small, independent gametophyte that is green and photosynthetic.
- Fertilization: The gametophyte produces both antheridia and archegonia. Fertilization occurs when sperm reaches the egg within the archegonium, leading to the development of a new sporophyte.
3. Pteris
Morphology:
- Habit: Pteris is a genus of ferns that typically grows in a variety of habitats, including tropical and subtropical regions.
- Fronds: The fronds are typically large, pinnate (feather-like), and compound, with leaflets arranged along a central rachis.
- Roots: Roots are adventitious, arising from the base of the stem.
Anatomy:
- Vascular System: Pteris ferns have a vascular system with a central cylinder of vascular tissue in the stem. The xylem and phloem are arranged in a more complex pattern compared to simpler pteridophytes.
- Leaf Structure: The fronds have a well-developed vascular system with vascular bundles running throughout the leaflets.
- Sori: Sori, clusters of sporangia, are found on the underside of the fronds.
Reproduction:
- Sporophyte Generation: Pteris ferns are homosporous, producing only one type of spore.
- Spore Production: Spores are produced in sori, which are located on the underside of the fronds. Each sorus is covered by a protective structure called an indusium.
- Gametophyte Formation: Spores germinate into a small, heart-shaped gametophyte called a prothallus.
- Fertilization: The prothallus bears both antheridia and archegonia. Fertilization occurs when sperm from the antheridia reaches the egg in the archegonium. This results in the formation of a zygote that develops into a new sporophyte.
Ecological and economical importance of Pteridophytes
Ecological Importance
- Habitat Formation and Biodiversity Support
- Forest Ecosystems: Pteridophytes contribute to the complexity of forest ecosystems. They provide habitat and shelter for various microorganisms, insects, and small animals.
- Biodiversity: By forming dense ground cover in many ecosystems, they support a range of species, contributing to overall biodiversity.
- Soil Stabilization
- Erosion Control: Many pteridophytes, such as Selaginella, play a crucial role in preventing soil erosion. Their extensive root systems help stabilize soil, reducing the risk of landslides and promoting soil health.
- Soil Enrichment: The decomposition of pteridophyte fronds adds organic matter to the soil, enhancing soil fertility and structure.
- Moisture Regulation
- Water Retention: Pteridophytes contribute to maintaining soil moisture. Their presence in damp and shaded environments helps regulate local humidity and prevents soil desiccation.
- Carbon Sequestration
- Climate Regulation: As photosynthetic organisms, pteridophytes absorb carbon dioxide from the atmosphere, aiding in carbon sequestration and thus helping mitigate climate change.
Economic Importance
- Agricultural Use
- Animal Feed: The dry fronds of certain ferns are utilized as feed for livestock, particularly in regions where other feed sources are limited.
- Medicinal Applications
- Lycopodium: Used in traditional medicine for treating skin conditions and other ailments.
- Dryopteris: Provides compounds used in the preparation of anthelminthic drugs, which are essential for treating parasitic infections.
- Human Consumption
- Food Source: Pteridium aquilinum, or bracken fern, is consumed as a traditional food source in various cultures. It provides nutritional benefits and is a staple in some diets.
- Ornamental Value
- Gardening and Landscaping: Ferns and other pteridophytes are valued for their aesthetic qualities. They are widely cultivated for decorative purposes in gardens and indoor spaces due to their lush foliage and varied forms.
- Environmental Management
- Soil Conservation: Pteridophytes such as Selaginella assist in soil conservation efforts by stabilizing soil and preventing erosion, which is beneficial for land management and agricultural practices.
Resemblances to Bryophytes
Pteridophytes share several characteristics with bryophytes, highlighting their evolutionary connections:
| Characteristic | Pteridophytes | Bryophytes | Similarity |
|---|---|---|---|
| Heteromorphic Alternation of Generations | Both exhibit a life cycle with alternation between haploid gametophyte and diploid sporophyte. | Both exhibit a life cycle with alternation between haploid gametophyte and diploid sporophyte. | Both groups share this reproductive strategy involving two distinct life stages. |
| Oogamous Reproduction | Sexual reproduction involves motile sperm and non-motile egg, with structures called antheridia and archegonia. | Sexual reproduction involves motile sperm and non-motile egg, with structures called antheridia and archegonia. | Both groups use oogamous reproduction involving specific reproductive structures. |
| Water Dependency | Water is essential for fertilization, aiding in the opening of sex organs and fusion of gametes. | Water is essential for fertilization, aiding in the opening of sex organs and fusion of gametes. | Both groups rely on water for successful fertilization and reproduction. |
| Homosporous Condition | Some pteridophytes are homosporous, producing a single type of spore that develops into gametophytes capable of producing both gametes. | Bryophytes are always homosporous, producing a single type of spore that develops into gametophytes capable of producing both gametes. | Both groups share the homosporous condition, producing spores that give rise to bisexual gametophytes. |
Differences Between Bryophytes and Pteridophytes
| Characteristic | Pteridophytes | Bryophytes | Difference |
|---|---|---|---|
| Plant Body Structure | Plant body is differentiated with distinct roots, stems, and leaves. | Plant body is thalloid or foliose, lacking distinct roots, stems, and leaves. | Pteridophytes have a more complex structure compared to the simpler bryophytes. |
| Vegetative Reproduction | Less frequent; primarily relies on sexual reproduction. | Commonly uses vegetative reproduction. | Bryophytes more often reproduce vegetatively, while pteridophytes do so less frequently. |
| Spore Type | Many are heterosporous, producing microspores and megaspores. | Exclusively homosporous, producing one type of spore. | Pteridophytes exhibit heterospory with two spore types, unlike the homosporous bryophytes. |
Resemblances to Gymnosperms
Pteridophytes also share similarities with gymnosperms, reflecting their advanced evolutionary traits:
| Characteristic | Pteridophytes | Gymnosperms | Resemblance |
|---|---|---|---|
| Sporophytic Plant Body | Plant body is primarily sporophytic with well-differentiated roots, stems, and leaves. | Plant body is primarily sporophytic with well-differentiated roots, stems, and leaves. | Both groups share a sporophytic plant body structure with distinct organs. |
| Vascular System | Possesses a developed vascular system, including xylem and phloem for nutrient and water transport. | Also has a developed vascular system, including xylem and phloem for nutrient and water transport. | Both have a well-developed vascular system. |
| Heterospory | Many species exhibit heterospory, producing distinct types of spores. | Heterospory is present in many species, producing distinct types of spores. | Both groups display heterospory. |
| Ciliated Antherozoids | Antherozoids (sperm) in some species are ciliated. | Antherozoids (sperm) in some species are also ciliated. | Both have ciliated antherozoids in some species. |
Differences Between Pteridophytes and Gymnosperms:
| Characteristic | Pteridophytes | Gymnosperms | Difference |
|---|---|---|---|
| Habitat | Typically found in moist and shaded environments. | Adapted to xerophytic (dry) habitats. | Pteridophytes prefer moist environments, while gymnosperms thrive in dry conditions. |
| Root Structure | Features ephemeral taproots, which are soon replaced by adventitious roots. | Develops permanent taproots. | Pteridophytes have temporary taproots, whereas gymnosperms have enduring taproots. |
| Archegonial Structure | Archegonium includes neck canal cells. | Neck canal cells are absent in the archegonium. | Pteridophytes have neck canal cells in their archegonia, unlike gymnosperms. |
References
- https://www.jsscacs.edu.in/sites/default/files/Department%20Files/AN-%20HC%201.2-%20PTERIDOPHYTES_compressed%20%282%29_compressed.pdf
- https://www.brainkart.com/article/Pteridophyta–the-ferns—Growing-Diversity-of-Plants_17049/
- https://www.vedantu.com/biology/pteridophytes
- https://www.geeksforgeeks.org/pteridophyta-definition-characteristics-classification-uses/
- https://www.toppr.com/guides/biology/plant-kingdom/pteridophytes/
- https://en.wikipedia.org/wiki/Pteridophyte
