VASCULAR PLANTS FERN AND FERN ALLIES Tracheophytes The

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 � demonstrate increased levels of organization

Major evolutionary advances of the vascular plants

Major evolutionary advances of the vascular plants

Major evolutionary advances of the vascular plants

PRIMITIVE VASCULAR PLANTS: THE FERN ALLIES

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) �bilobed synangia of Tmesipteris �trilobed synangia of Psilotum � resembles Cooksonia what paleobotanists believe

CHARACTERISTICS: 1. Underground rhizome 2. Unicellular rhizoids 3. Erect stems dichotomize into the main photosynthetic organ

REPRESENTATIVE species � Psilotum (2 species) and Tmesipteris (25 species)

TRUE FERNS

Division Pteridophyta � reproduce by spores from which the free -living bisexual gametophyte generation develops � megaphyllous leaves � 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