1. Mosses and Their Relatives
Bryophytes
Mosses and Their Relatives

2. Lack true stems, leaves, or roots
bryophytes
Lack true stems, leaves, or roots
Are non-vascular which means they do not have vascular tissues
Vascular tissues are specialized to conduct water and nutrients

3. Grow in almost all biomes: tropical, temperate and polar
Since they don’t have vascular tissue, how do they get water and nutrients to all of their cells?
They must be in a wet environment
Sperm must swim to eggs
Need rainfall or dew for at least part of the year
They cannot grow very tall
No true roots
Have rhizoids
Long, thin cells that anchor them and absorb water and minerals
Water moves through via osmosis
Their “leaves” are only one cell layer think to allow for movement of water and minerals
Grow in almost all biomes: tropical, temperate and polar

4. Three groups
Mosses
Liverworts
Hornworts

5. mosses
Most common
Grow in swamps, bogs, near streams and rain forests where there is a lot of moisture
Well adapted to wet habitats and poor soil
Tolerate low temperatures making them the most abundant plant in polar regions
 Green part we are familiar with is the gametophyte
Thin stalk with capsule at top formed for reproduction is the sporophyte

7. liverworts Flat plants resembling the shape of a liver
Broad, flat, thin structure called gametophyte which draws moisture directly from surface
Need damp soil nearly year round
Umbrella like structures for reproduction called sporophytes 
Some can produce asexually via structures called gemmae
Very cool little system
Gemmae produced in gemma cup
Get washed out of cups and can then reproduce via mitosis

8. hornworts
Similar to liverworts
Sporophyte looks like a tiny green horn

9. Life cycle: part 1 Gametophyte is dominant
Easily recognizable
Carries out most of the photosynthesis
Sporophyte depends on gametophyte to supply water and nutrients 
Reproduction cycle is alternation of generations
Moss spore germinates (if conditions are correct) 
Grows into protonema (look it up!)
Rhizoids form that grow into ground
Shoots form that grow into air
Form gametophyte

10. Life cycle: part 2 Gametes develop Sperm develop in antheridia
Eggs develop in archegonia
Depending on species, may have both structures on one plant or on separate plant 
Sperm release and swim to egg
Fertilization occurs forming diploid zygote
Zygote is beginning of sporophyte stage
Sporophyte grows out of gametophyte
Haploid spores produced in capsule via meiosis
When mature, capsule opens, spores released, spread and cycle starts again

12. Ecology of mosses Natural sponges absorbing large amounts of water
Can be used to reduce water loss from plant containers
Dead remains accumulate forming thick deposits of peat
Useful as fuel
Useful in gardens
Improves water retention
Increases soil acidity which is good for some plants