Phyla of Bryophytes

General Botany Lab

Bryophytes General Characteristics:

Among the most ancient terrestrial plants

Small in size; can colonize sterile soils

Essential for nutrient cycling and soil formation

Found in humid and shady habitats

Water is required for sexual reproduction

Bryophytes Phyla:

Bryophyta

Hepatophyta

Anthocerotophyta

Bryophyta:

Mosses

Bryophyta Dominant Phase:

Gametophyte (n)

Bryophyta Gametophyte Male:

Produces antheridia

Bryophyta Gametophyte Female:

Produces archegonia

Bryophyta Gametophyte Rhizoids:

Multicellular structures for anchorage

Bryophyta Gametophyte Structures:

Leaf-like structures with a costa (midvein-like structure)

Bryophyta Reproductive Structures:

Antheridial Head

Archegonial Head

Antheridial Head:

Found at tips of male gametophytes

Houses antheridia with sperm cells

Archegonial Head:

Found at tips of female gametophytes

Houses archegonia with eff cell

Bryophyta Fertilization:

Sperm cells splash to archegonia via water

Swim to the archegonium’s neck, fertilizing the egg in the venter

Forms a zygote (2n), initiating sporophyte development

Bryophyta Sporophyte:

Dependent on gametophyte for nutrition

Develops within the archegonium

Composed of: Capsule, Calyptra

Bryophyta Capsule:

Spore production site via meiosis

Bryophyta Calyptra:

remnant of gametophyte tissue covering the capsule

Bryophyta Life Cycle:

1. Meiosis in the capsule → Haploid spores

2. Spores germinate into protonema

3. Protonema develops into gametophyte with antheridia and archegonia

4. Fertilization produces a zygote → Sporophyte

Hepatophyta:

Liverworts

Hepatophyta General Features:

Thallus

Rhizoids

Leafy gametophytes lack a costa

Biflagellate sperm

Monoecious or dioecious species

Thallus:

Some resemble liver in shape; many are leafy

Rhizoids:

Unicellular

Hepatophyta Reproductive Structures:

Antheridiophores

Archegoniophores

Antheridiophores:

Structures that bear antheridia (produce sperm)

Archegoniophore:

Structures that bear archegonia (produce eggs)

Hepatophyta Sporophyte:

Forms after fertilization within the archegonium

Develops into a capsule (2n)

Hepatophyta Asexual Reproduction:

Gemmae cups on the thallus produce gemmae (n)

Gemmae are dispersed by rain and develop into new gametophytes

Hepatophyta Example:

Marchantia

Marchantia:

Gametophytes with distinct antheridiophores and archegoniophores

Life cycle includes both sexual and asexual reproduction