Q.57 Which one of the following is a peat moss?
1. Pellia
2. Sphagnum
3. Marchantia
4. Funaria
Sphagnum is the peat moss, forming extensive bogs through its water-holding dead tissue that accumulates as peat. Other options are bryophytes but lack this defining peat-forming trait.
Peat Moss Characteristics
Peat mosses (Sphagnum spp.) are acrocarpous bryophytes thriving in acidic wetlands, with unique hyaline cells for massive water retention (20x dry weight).
Dead lower stems decay slowly, forming peat deposits used in horticulture for aeration and moisture.
Over 300 species dominate northern bogs, key in carbon sequestration.
Correct Answer: 2. Sphagnum
Sphagnum is universally recognized as “peat moss” due to its bog-forming habit and commercial peat harvesting from Sphagnum-derived deposits.
Its spiral-retaining cell walls prevent collapse, maintaining spongy structure in peat.
Option Breakdown
| Option | Group & Habitat | Peat Moss? | Explanation |
|---|---|---|---|
| 1. Pellia | Thalloid liverwort (Pelliales) | No | Simple flat gametophyte; no peat formation. |
| 2. Sphagnum | Peat moss (Sphagnales) | Yes | Bog specialist; dead tissue → peat. |
| 3. Marchantia | Thalloid liverwort (Marchantiales) | No | Gemmae cups; dichotomous thallus; terrestrial. |
| 4. Funaria | True moss (Funariaceae) | No | Cushion moss; common on soil; no peat role. |
Ecological Role
Sphagnum acidifies water (pH 4-5), creating unique habitats; peat stores 30% global soil carbon.
Harvesting sustainable due to slow growth (1mm/year accumulation).
