Seedless vascular plants have xylem and phloem but no seeds

seedless vascular plants

has xylem and phloem but does not produce seeds

1. includes ferns and their close relatives

2. have true roots, leaves and stems

   1. in many species, the leaves and roots arise from underground stems call rhizomes

13,000

About how many seedles vascular plants are there?

fossil evidence

earliest species are exinct but preserved in

silurian period 425 mya

When did seedless vascular plants originate?

club moss

What type of moss is descended from seedless vascular plants?

vascular tissue

What enables plants to grow much larger in height and girth than nonvascular plants and also allowed for diversification?

rhizomes

underground stems

1. sometimes also store carbohydrates that provide energy for the growth of new leaves and roots

2

How many phyla are there for seedless vascular plants?

4

How many lineages are the two phyla for seedless vascular plants divided into?

club mosses

phylum Lycopodiophyta

1. small plants in genus Lycopodium

2. have simple leaves resembling scales or needles

3. club-shaped reproductive structures

4. close relatives are spike mosses (Selaginella)

5. collectively, this and spike mosses are somtimes called lycopods

lycopods

club+spike mosses

Whisk Ferns

phylum Pteridophyta

1. simple plants that have rhizomes but not roots

2. no obvious leaves

3. Psilotum branches —> resemble whisk brooms

horsetails

phylum Pteridophyta

1. grow along streams or at borders of forests

2. also called scouring rushes because their stems and leaves contain abrasive hsilica particles

3. only living genus —> Equisetum

   1. includes plants with branched rhizomes that give rise to green aerial stems bering spores at their tips

true ferns

phylum Pteridophyta

1. largest group of seedless vascular plants

2. about 11,000 species

3. widespread and abundant during Carboniferous period

   1. huge frond in most forests

Azolla

tiny species of true fern that lives in water

1. their leaves house cyanobacteria that fix nitrogen

sporophyte

produces haploid spres by meiosis in collections of sporangia on the unsersie of each frond

1. once shed, the spores germinate and develop into tiny, heart shaped gametophytes that produce gametes by mitotic cell division

   1. the swimming sperm require a film of water to reach an egg cell (typically a different gametophyte)

      1. The gametes fuse, forming a zygote —→

         this diploid cell divides mitotically and forms the sporophyte, which quicklhy dwarfs the gametophyte

shady moist habitats

Where do many seedless vascular plants live?

production of swimming sperm

How are seedless vascular plants similar to bryophytes?

1. because of this, they cannot reproduce sexually in the absence of water