Plant Diversity 1: The Colonization of Land Plant Unit Plant Diversity 1: The Colonization of Land

The Colonization of Land An Overview of Plant Evolution Structural, chemical, and reproductive adaptations enabled plants to colonize land The history of terrestrial adaptation is the key to modern plant diversity The Origin of Plants Plants probably evolved from green algae called charophytes Alternation of generations in plants may have originated by delayed meiosis Adaptations to shallow water preadapted plants for living on land

The Colonization of Land Bryophytes The embryophyte adaptation evolved into bryophytes The gametophyte is the dominant generation I the life cycle of bryophytes The three divisions of bryophytes are mosses, liverworts, and hornworts The Origin of Vascular Plants Additional terrestrial adaptations evolved as vascular plants descended from bryophyte-like anscestors The branched sporophytes of vascular plants amplified the production of spores and made complex bodies possible Seedless Vascular Plants A sporophyte-dominant life-cycle evolved in seedless vascular plants The three divisions of seedless vascular plants are lycophytes, horsetails, and ferns Seedless vascular plants formed vast “coal forests” during the carboniferous period

Chara

Coleochaete

Charophyceans

Apical Meristems

Marchantia Embryo

Embryos of Land Plants

Alternation of Generation

Fern Spore

Hornwort Sporangium

Archegonium Antheridium Gametangia

Cuticle

Polypodium Stem

Phloem and Xylem

Fossil Spores and Tissue

Plant Alternation of Generation Hypothesis

Thalloid Liverwort, Leafy Liverwort, [Bryophyte collage] Thalloid Liverwort, Leafy Liverwort, Hornwort and Moss

Quillwort

Polytrichum Life- Cycle

Gametophytes

Archegonium

Sporophytes

Sporangium

Spores

Protonemata

Moss Life Cycle

Sporophyte Section

Moss Sporangium

Peat Moss Bog

Sphagnum Moss

Sphagnum Leaf

Pteridophytes: Club Moss, Whisk Fern, Horsetail, Polypodium Fern

Lycophyte

Leaf Evolution Hypothesis

Fern Life Cycle

Mature Fern

Sorus

Sporgangium

Mature Sporangium

Germinating Spore

Gametophyte

Archegonia

Sporophytes

Polypodium Fern

Polypodium Sori

Polypodium Sorus

Carboniferous (replica)

The Colonization of Land An Overview of Plant Evolution Structural, chemical, and reproductive adaptations enabled plants to colonize land The history of terrestrial adaptation is the key to modern plant diversity The Origin of Plants Plants probably evolved from green algae called charophytes Alternation of generations in plants may have originated by delayed meiosis Adaptations to shallow water preadapted plants for living on land

The Colonization of Land Bryophytes The embryophyte adaptation evolved into bryophytes The gametophyte is the dominant generation I the life cycle of bryophytes The three divisions of bryophytes are mosses, liverworts, and hornworts The Origin of Vascular Plants Additional terrestrial adaptations evolved as vascular plants descended from bryophyte-like anscestors The branched sporophytes of vascular plants amplified the production of spores and made complex bodies possible Seedless Vascular Plants A sporophyte-dominant life-cycle evolved in seedless vascular plants The three divisions of seedless vascular plants are lycophytes, horsetails, and ferns Seedless vascular plants formed vast “coal forests” during the carboniferous period