Sphagnum - Diagram, Classification, Uses, Reproduction and Life Cycle

Sphagnum:  Sphagnum, also known as peat moss, sphagnum moss, or bog moss, is a genus of mosses with approximately 380 accepted species.  These mosses are ecologically significant because they produce peat moss, which acts as a carbon sink in the ecosystem. Sphagnum thrives in wet, boggy environments and requires acidic soil conditions.  Sphagnum is notable for its ability to store large amounts of water, with both living and dead plants retaining 16 to 26 times their dry weight, depending on the species. Detailed NEET Biology notes on Sphagnum are provided in the article below.

Free Study Material for NEET Preparation

Sphagnum Diagram

Sphagnum Classification

Explore - NEET Online Courses by PW

Sphagnum Structure

Gametophyte (Dominant Phase)

Cell The Unit of Life

• Pith: The inner core responsible for food production and storage.
• Cortical Layer: The outer layer containing specialized cells for water absorption and protection. Sphagnum moss lacks a vascular system, so its tissues are typically one cell thick to facilitate diffusion.

• Chlorophyllose Cells: Small, green, living cells with chlorophyll that produce food through photosynthesis.
• Hyaline Cells: Large, dead, empty cells without chlorophyll, with perforated walls that allow the plant to hold water up to 30 times its dry weight. This water-holding capacity is crucial for survival in bogs and waterlogged habitats.

Structural Organisation in Animals

Sporophyte (Reproductive Phase)

• Capsule: The spore-bearing structure, consisting of a central columella surrounded by a spore sac and a protective outer wall. The capsule is covered by a disc-shaped lid (operculum), which pops off to release spores for dispersal.

Sphagnum Characteristics

1. Water Retention: Sphagnum moss can retain large amounts of water, up to 20 times its dry weight, due to its specialized cells known as hyaline cells.
2. Acidic Environment: It creates an acidic environment by releasing organic acids, which lower the pH of the surrounding water and soil.
3. Peat Formation: As Sphagnum decomposes, it forms peat, a dense, waterlogged layer that builds up over time and captures carbon.
4. Growth Form: Sphagnum grows in thick mats or cushions. The older parts decompose into peat while the upper parts remain alive.
5. Leaf Structure: The leaves contain large, empty hyaline cells for water retention and smaller chlorophyllose cells for photosynthesis.
6. Reproduction: It mainly reproduces asexually through fragmentation but also reproduces sexually by producing spores.
7. Habitat: Sphagnum moss is commonly found in bogs, fens, and wetlands, thriving in cool and moist environments.
8. Color: The color of Sphagnum moss varies from green to red, depending on the species and environmental conditions.
9. Global Distribution: Sphagnum moss is found worldwide, particularly abundant in the Northern Hemisphere's boreal and temperate regions.
10. Ecological Role: It plays a crucial role in storing carbon and maintaining wetland ecosystems.

Sphagnum Uses

• Soil Amendment: Improves soil structure by retaining water and nutrients.
• Seed Starting and Growing Medium: Ideal for starting seeds and cultivating plants like orchids.

• Carbon Sequestration: Sphagnum bogs trap CO2, aiding in climate change mitigation.
• Habitat Creation: Supports diverse ecosystems in peatlands and bogs.

• Packaging Material: Cushions and regulates moisture.
• Preservation : Used to preserve food and biological specimens.

• Floral Arrangements: Retains moisture and adds natural beauty.
• Craft Projects: Used in terrariums and model landscapes.

• Bedding Material: Soft and insulating.
• Construction: Peat used in traditional building materials.

Sphagnum Reproduction

Vegetative Reproduction

Medulla Oblongata

Sexual Reproduction

• The gametophyte stage is the dominant phase in Sphagnum's life cycle.
• It includes the juvenile protonema (initial growth) and the leafy gametophore (mature stage).
• Young gametophytes have multicellular rhizoids, but mature ones do not.
• The main stem becomes upright and thick, with many branches.
• Leaves are small, sessile, and lack a distinct midrib.

• Antheridia develop on specialized male branches.
• They are club-shaped, with a long multicellular stalk and a globular body.
• Inside the antheridium, androgonial cells develop into spirally coiled sperm with flagella.

Bones in Human Body

• Archegonia grow on specialized female branches.
• They are flask-shaped, with a swollen neck and a long twisted venter.
• The neck has six vertical layers of neck cells and cover cells.
• The venter contains a ventral canal cell and a basal egg cell.

• Fertilization occurs in the presence of water.
• Sperm cells swim up to the archegonia.
• The neck canal cells and ventral canal cells disorganize to form a passage for sperm entry.
• The sperm reaches the egg cell, resulting in the formation of a diploid zygote.

Female External Genitalia

Sphagnum Life Cycle

1. Spores: The cycle starts with spores produced in capsules on the diploid sporophyte. These spores are dispersed by wind or water.
2. Protonema: When spores land in a moist environment, they germinate into a filamentous protonema. This stage is short-lived but essential for developing the next phase.
3. Gametophore: Buds on the protonema grow into the leafy gametophore, the familiar green moss plant. Unlike other mosses, mature gametophores of Sphagnum lack rhizoids and absorb water directly through their leaves.
4. Sexual Reproduction: Sphagnum can be unisexual (separate male and female plants) or bisexual (both male and female organs on one plant). Fertilization occurs when a sperm from the antheridium (male organ) reaches an egg in the archegonium (female organ).
5. Sporophyte: Fertilization forms a diploid sporophyte, which relies on the gametophore for nutrition. It develops in the capsule on the archegonium of the gametophore.
6. Spore Release: The sporophyte matures, undergoes meiosis, and produces haploid spores. The capsule splits, releasing the spores to begin the cycle again.

Economic Importance of Algae