Primitive vascular plants evolved adaptations for life on land including vascular tissue for transport and alternation of generations. They include psilophytes which were the earliest vascular plants with no specialized organs, lycophytes with true roots, stems and scale-like leaves requiring water for reproduction, and sphenophytes with whorled leaves and siliceous stems requiring water for motile sperm. Advanced ferns have well-developed vascular tissue and xylem and phloem, thriving in damp habitats with a dominant sporophyte and inconspicuous gametophyte reproducing via spores in sori on fronds.

1. PRIMITIVE VASCULAR
PLANTS
Ferns and Fern Allies

2. Adaptations to life on land
vascular tissue – specialized tissues for
transport
xylem – e.g. tracheid  Tracheophyta
phloem
 complex organization – possess true plant organs
(basic structure and function)

3. root
stem
leaf (cuticle)
 alternation of generations – sporophyte dominant
(gametophyte independent in primitive forms,
dependent on s’phyte in advanced forms)
embryophyte condition – gametes and
embryo protected (no need for env’l
water)

4. Psilophytes (Whisk Ferns)

5.  whisk ferns
 first vascular plants (earliest to evolve accdg to
the fossil record  extinct or not extinct)
 no specialized organs  no differentiation
between root and shoot
 small and creeping
 sporophyll  specialized leaves containing
sporangia
 motile sperm swims in water
 e.g. Psilotum

6. Lycophytes (Club Mosses)

7.  club mosses
 true roots, stems and leaves (small and scale-
like, arranged spirally)
 sporophyll  specialized leaves containing
sporangia
 water required for reproduction
 e.g. Lycopodium (ground pine)
 Selaginella

8. Sphenophytes (Horse Tails)

9.  horsetails
 leaves arranged in whorls (small & simple) on
the stem (siliceous)
 motile sperm must swim in water
 e.g. Equisetum (scouring rush)

10. Pterophytes (Ferns)

11.  vascular tissue well-developed  w/ xylem &
phloem
 thrive in predominantly damp or seasonally wet
habitats
 sporophyte dominant, gametophyte
inconspicuous
 structure of the sporophyte:
leafy frond bearing sori (sorus) ctg.
spores
fiddlehead with circinate vernation

12. rhizome (underground stem)
 structure of the gametophyte
heart-shaped prothallus
rhizoids
antheridia & archegonia  reproduction
requires water
 e.g. Pteris, Adiantum, Christella