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Vascular plants: FERN and FERN ALLIES. Tracheophytes : The Vascular Plants. xylem (for transporting water and mineral nutrients) phloem (for transporting sugars from leaves to the rest of the plant) larger and more complex sporophyte is more prominent
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Tracheophytes: The Vascular Plants • xylem (for transporting water and mineral nutrients) • phloem (for transporting sugars from leaves to the rest of the plant) • larger and more complex • sporophyte is more prominent • demonstrate increased levels of organization
Division Lycophyta: club mosses • oldest extant group of vascular plants • sporangia organized into strobili (sing.: strobilus) • may be either HOMOSPOROUS or HETEROSPOROUS • Leaves that contained vascular tissue
REPRESENTATIVE SPECIES • Lycopodium • isospores • bisexual gametophyte
REPRESENTATIVE SPECIES • Selaginella • small spores (microspores) that germinate to produce the male gametophyte • larger spores (megaspores) that germinate to produce the female gametophyte
Division Sphenophyta:scouring rushes • leaves produced at a node (WHORLS) • production of isospores • spores bearing elaters (devices to aid in spore dispersal) • gametophyte is small, photosynthetic and free-living • Silica concentrated • jointed stems
Division Psilophyta • traditionally considered to be the oldest living lineage of vascular plants • lack roots • stem is photosynthetic • no leaves but rather minute enations
sporangia occur in fused groups (synangia) • bilobedsynangia of Tmesipteris • trilobedsynangia of Psilotum • resembles what paleobotanists believe Cooksonia
CHARACTERISTICS: 1. Underground rhizome 2. Unicellular rhizoids 3. Erect stems dichotomize into the main photosynthetic organ
REPRESENTATIVE species • Psilotum (2 species) and Tmesipteris (2-5 species)
Division Pteridophyta • reproduce by spores from which the free-living bisexual gametophyte generation develops • megaphyllousleaves • leaf is called a frond • fiddleheads • central axis of a compound frond is called the rachis
ANTHERIDIUM ARCHAEGONIUM
READING ASSIGNMENT • READ ON GYMNOSPERMS AND ANGIOSPERMS • You may also use Biology by Campbell and Reece