BRYOPHYTES | GENERAL CHARACTERISTICS, CLASSIFICATION

Bryophytes 

The word "bryophyte" comes from Greek bryon, "tree-moss, and phyton means "plant". 

Oldest land plants on earth.

General Characteristics

• Bryophytes do not have true vascular tissue and thus they are non-vascular plants, among the simplest of the terrestrial plants. 

• They are lacking cuticle and stomata, roots, stems or leaves.

• Cell wall contains cellulose.

• They are small, ground-hugging and moisture- loving plant.

• Most are 2–5 cm (0.8–2 inches) in length or sometime the length increases more than one meter. 

• Length is also limited by the absence of lignin.

▪ Bryophytes lack true leaves. But they have leaf-like scales containing chloroplasts in which photosynthesis takes place.

▪ They lack true stems and true roots.

➢ They have root-like structures called rhizoids through which they anchor themselves in soil.

All of bryophytes are land plants with some aquatic forms.

• Morphologies of sporophyte and gametophyte are different (heteromorphic generations).

Classification Bryophyta into three classes

1. Bryopsida

e.g., Mosses, Funaria

2. Hepatica 

e.g., Liverworts-Riccia and Marchantia

3. Anthocerotae 

e.g., Hornworts, Anthoceros

1: Class Hepaticae (Liverworts)

▪ Because of resemblance of the lobes of the thallus with the lobes of the liver, the name liverwort arose.

Occurrence 

Liverworts seem as small, flat green patches that are attached to ground. Even though they may in abundance in favorable habitats e.g., moist, shaded rocks or soil, tree trunks or branches and some even directly grow in water.

General characteristics of Liverworts

They are flowerless and spore-producing plant.

• Generally small; 2-20 mm wide with individual plants less than 10cm in length.

• The most familiar liverworts have a prostrate, flattened, ribbon-like or 

branching structure known as a thallus (plant body). These liverworts are called thallose liverworts. 

• But most liverworts have flattened stems with overlapping scales or 

leaves in two or more ranks. These are known as leafy liverworts or scale liverworts.

 2. Class Anthocerotae (Hornworts) 

The sporophytes of hornworts appear as small green broom handles.  

Hornworts may be present all over the world, though they favor to grow only in damp or humid places. They may be growing on the bark of trees. Only one hundred species identified.

3. Class Bryopsida (Mosses)

▪ Generally, the body of the moss is leafy-like.

▪ Most favor damp, shaded locations in the temperate zone.

▪ Mosses may also reproduce by budding (asexually).

▪ They are small, soft plants that are commonly 1-10 cm tall.

▪ Some found on rocks and in arid locations 

▪ They are flowerless and seedless