Seedless Plants
Feb 12, 2016
Seedless Plants
Plant Evolution
Plant Evolution Nonvascular Seedless plants
– (Ordovician - 475 mya) Vascular Seedless plants
– (Devonian - 400 mya) Vascular Seed plants
– (Carboniferous - 360 mya) Flowering plants
– (Cretaceous - 130 mya)
Plant Evolution(Common with Algae)
Multicellular and Eukaryotic Cell walls made of Cellulose Chlorophyll a and b Store excess sugar as starch
Charophyceans Homologous Cell Walls Peroxisome enzyme
(Photorespiration) Homologous
Chloroplasts Sperm ultrastructure Phragmoplasts (Mitosis
& Cytokinesis) Genetic Relationships
Adaptations to Terrestrial Life
Apical Meristems Multicellular Dependent Embryos Alternation of Generation Walled Spores produced in Sporangia Other Adaptations
– Cuticle, stomata, Xylem & Phloem, secondary compounds
Apical Meristems
Multicellular Dependent Embryos
Alternation of Generation
Walled Spores produced in Sporangia
Other Adaptations
Adaptations in Shallow Water Algae
Subjected to occasional drying Protection of gametes and embryos in
gametangia Sporopollenin
Classification of Seedless Plants
Nonvascular Seedless plants– Bryophyta
Mosses– Hepatophyta
Liverworts– Anthocerophyta
Hornworts
Vascular Seedless plants– Lycophyta
Club mosses– Psilophyta
Whiskferns– Spenophyta
Horsetails– Pterophyta
Ferns
Nonvascular Seedless Plants
Plant is a thallus (no vascular tissue)– no true leaves, roots, stems
Embryophytes– gametangia
(antheridium and archegonium)– sporangium (produces spores)
Hepatophyta
Liverworts– Two forms
leafy (80%) thalloid (20%)
Hepatophyta Liverworts
– Reproduction asexual
(gemmae cups) sexual
Anthocerophyta Hornworts
– Similar to liverworts except for sporophytes
– Most closely related to higher plants
BryophytaMosses
Bryophyta
Mosses
Vascular Seedless Plants Formation of vascular tissue
– Xylem (water)– Phloem (food)– True leaves, roots, and stems
Lignin Sporophyte generation dominate Sperm with flagella
Lycophyta Lycophytes
– true leaves microphylls
– true stems– true roots– sporophylls
leaves that produce spores
Psilophyta Whisk Ferns
– no true leaves– no true roots
Sphenophyta Horsetails
– true leaves microphylls
– true stems silica
– true roots
Division: Pterophyta
Division: Pterophyta
Fern Life Cycle