BRYOPHYTES (23.3)

Tasha Fisher and Emily Crawford

What are Bryophytes?

Archidium ohioense, a moss

Include the mosses, liverworts, and hornworts.

Are the simplest of plants. About 20,000 species Found throughout the world,

but are prevalent in moist and shady areas can be found in alpine regions,

where they are subjected to freezing, and some in deserts, where they are desiccated most of the time

Many are highly specialized, and found in restricted habitats

Unique Characteristics

Gottschelia schizopleura, a liverwort

Lack vascular tissue must absorb all water and nutrients at

the surface and pass them from cell to cell.

few have modified water transport cells called hydroids, and a few have solute conducting cells, called leptoids, but this is rare.

leaves are not true leaves because most species lack vascular tissue.

Leaves are functionally equivalent to “real leaves” because they contain chlorophylls a and b.

“Leaves” are usually one-cell thick, except for the midrib, which may be up to 15 cells thick.

satisfy their nutritional requirements by absorbing minerals from dust, rainfall, and water running over their surface.

Lack of Vascular Tissue

Unique Characteristics

Phaeoceros oreganus, a hornwort

Bryophytes are small and the tallest are 20 cm in height while the shortest are about 2 cm in height.

Often grow in prostrate masses or clumps because they don’t have any vascular tissues needed for upright growth.

They do not have roots therefore they attach to the soil with rhizoids.

Most of them are soft and pliable.

Unique Characteristics

Barbula indica,

a moss

Survive best in moist habitats but many can tolerate dry areas by lowering metabolic needs.

Also known as desiccating All mosses, liverworts, and

hornworts have three traits that they share and that evolved in early plants: a waxy cuticle, cellular jacket, and large gametophytes.

If they dry out, they can simply be revived by water.

Uses of Bryophytes

Japanese Moss

Garden

Mosses are used in gardening, agriculture, medicine, and the construction of homes.

Other uses for mosses are all-natural insect repellants, boot liners, and fuel.

Liverworts are sometimes used for medicinal purposes.

They also very useful in determining any environmental changes.

Life Cycle of Bryophytes

Varies among the three divisions In General….

Sperm is released from the antheridium and uses water to reach the egg in the archeogonium.

A zygote forms and undergoes mitotic division until it develops into an embryo.

Embryo grows until it becomes a sporophyte in which spores form.

The spores are then released and germinate. The spores will form either male or female gametophytes.

Life Cycle of Moss