2. Liverworts and Mosses
16,000 bryophytes species show some adaptations for life on land
They have root-like structures for anchoring called rhizoids
These structures can also bring water up but they have to rely on diffusion to distribute the water throughout the plant
Because of this most bryophytes are less than 2 cm. tall

4. Enclosed Reproductive Structures
These structures represent adaptation to terrestrial life
they prevent the gametes from drying out
The archaegonia house the eggs while antheridia house the sperm
some species have separate male and female plants
Some plants have both parts
In all species, the sperm has to swim to the egg

5. Liverwort archaegonia
Sperm cells have to swim up the stalks, through a film of water to fertilize the eggs

7. Tracheophytes Vascular plants
Two types of adaptations allowed some plants to become taller
Structures that provide support
vessels that conduct water and nutrients

8. Seedless Vascular Plants
These plants reached tree-like heights and dominated the landscape from 360 mya to 286 mya
Modern versions are the club mosses, ferns and horsetails
The ancient ancestors are coal today

9. CLUB MOSS
Lycopodium

10. HORSETAILS
Equisetum

11. FERNS

12. Lycopodium and Equisetum
There are only 15 species of horsetails
commonly called “scouring rushes”
they are abrasive due to deposits of silica in their outer layer of cells
club mosses are commonly called “ground pine”
all are only a few centimeters tall

13. Ferns There are 12000 species of ferns
In the tropics, there are “tree ferns”
Ferns are the only seedless plant with broad leaves
This gives them an advantage and may account for their relative success

14. Seed Plants Have dominated the land for the past 250 million years
this was made possible by the development of pollen and seeds
In seed plants both the female and male gametophytes are greatly reduced in size
the female gametophyte is a small group of cells that produce eggs
the pollen is the male gametophyte

15. The Seed It is analogous to the egg in birds and reptiles
The seed consists of an embryonic plant, a food supply for the embryo, and a protective coat
The embryo can lay dormant until the conditions are right for growth
Some seeds possess elaborate adaptations for dispersal

17. Gymnosperms Non-flowering seed plants There are three divisions
coniferophyta
ginkgophyta
cycadophyta

18. Conifers There are 500 species of conifers
They include pines, firs, spruce, hemlocks and cypresses
Most abundant in cold latitudes and high elevations
Their advantages are retaining their leaves all year as to photosynthesize when other plants are dormant

19. continued
And, their needle-like leaves have small surface area so evaporation is minimized
Third, they have a substance in their sap that acts like an anti-freeze. It also gives them the pine scent.

21. Ginkgo Were once widespread during the Jurassic period
Today, there is only one species, Ginkgo biloba
Ginkgos have separate male and female plants
they are very resistant to pollution and the males are used for landscaping

23. Cycads Kind of look like ferns but aren’t
There are about 160 species today
They live in the tropics and sub-tropical areas
Grow slowly and live for a loooooooong time
Some specimens are estimated to be 5000 years old
Seeds used to be food but they contain a neurotoxin so….not so much anymore

25. Angiosperms Flowering plants Incredibly diverse with 352,000 species
They can be a few millimeters wide (duckweed) to 328 feet tall (eucalyptus tree)
Have been around for more than 100 million years

26. Three Major Adaptations
Flowers
fruit
broad leaves
Broad leaves are appealing to herbivores so angiosperms have evolved lots of defense mechanisms
thorns, spikes, resins, toxins
Humans have used many of the poisons as medicine

29. Two Types of Angiosperms
Dicotyledons (dicots)
Monocotyledons (monocots)

30. Monocots About 65,000 species
Includes grasses, grains, corn, irises, lilies, and palms
Have one cotyledon or “seed leaf”
Vascular bundles (xylem and phloem) scattered throughout stem
Xylem conducts water up from roots
Phloem conducts sugars from photosynthesis

31. Dicots About 170,000 species Includes most trees, shrubs, and herbs
Have two cotyledons
Vascular bundles arranged in rings in stem