Download Vascular plants

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
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 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 (25 species)
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