Seedless Vascular Plants Ferns & Lycophytes Chapter 23
Seedless Vascular Plants 2 Groups Ferns Whisk Ferns Horsetails Lycophytes Club Mosses Spike Mosses Quillworts
Evolution from Bryophytes to Seedless Vascular Plants Development of Vascular Tissue Xylem – conducts water and dissolved minerals Phloem – conducts dissolved sugar Vascular tissue allows for taller plants Dominant sporophyte generation Reproduction still depends on water to transport sperm Evolution of True Leaves
Evolution of True Leaves 2 Types of True Leaves Microphylls Type of leaf found in lycophytes Contains one vascular strand Megaphylls Type of leaf found in ferns, horsetails, and seed plants Contains multiple vascular strands (branched) Probably evolved from the webbing of side branches
Evolution of True Leaves
Ferns Phylum Pteridophyta Remember: “I’m Terrified of Ferns” Seedless - Reproduce by spores produced in sporangia Spores are homosporous Give rise to bisexual gametophytes Vascular Undergo alternation of generations Dominant Sporophyte Generation Gametophyte generation (prothallus) Includes ferns, whisk ferns, and horsetails
Ferns An ancient group of plants Very diverse group
Parts of a Fern Rhizome – horizontal underground stem Frond- megaphyll leaf Fiddlehead – young, tightly coiled frond Sporangia – spore cases Sori – clusters of sporangia on bottom side of frond 6th hr left off here!
Fiddleheads
Sori
Fern Life Cycle
Prothallus – Fern Gametophyte
Whisk Ferns Exhibit Dichotomous branching Genera: Psilophyta
Horsetails Have hollow, jointed stems Stems contain silica Wet, marshy habitats Genera: Equisetophyta 2nd Hour Left off Here!
Lycophytes Phylum Lycopodiophyta Remember: “I Like-o-Fight with Clubs & Spikes, & go for the Quill” Seedless – Reproduce by spores Spores can be heterosporous 2 types of n spores – megaspores (form a female gametophyte) microspores (form a male gametophyte) Vascular Dominant Sporophyte generation Includes Club Mosses, Spike Mosses, & Quillworts 6th Hour left off here
3 Groups of Lycophytes Club Moss True roots Rhizomes & erect or trailing aerial stems Small, scale-like microphyll leaves 1st Hour 1st Hour Left off Here
3 Groups of Lycophytes 2. Spike Moss Long, creeping rhizomes Typically branch dichotomously Roots branch dichotomously Overlapping, scale-like microphylls 2nd Hour Left off here! Resurrection Plant
3 Groups of Lycophytes 3. Quillwort Underground corm A short, swollen underground stem Cylindrical, quill-like microphyll leafs Roots
Ecological & Economic Impacts Ferns & Lycophytes Help form soil Prevent soil erosion Branching underground rhizomes and roots or rhizoids hold soil in place Coal deposits Formed by remains of ancient ferns Powered Industrial Revolution of 19th Century Used today to produce electricity