Transcript Plants 4.2 - Hazlet.org

Seedless
Gymnosperm
Angiosperms
Vascular
Seed
PLANTS
Nonvascular
4-2: Seedless Plants
Mosses and Liverworts
-small
-grow on soil, tree bark, rocks
-no vascular system
-live in wet places
-don't have true stems, roots or leaves
-similar structures:
-rhizoids (like roots)
-slender, hairlike threads of cells
-help hold plant in place
Importance of Mosses and Liverworts
-First to inhabit new environment
-Form a thin layer of soil when they die
-Cover the soil and help hold it in place (reduces erosion)
-Birds use to make nests
-Peat mosses
-grow in bogs and other wet places
-dried and burned as fuel
Ferns, Horsetails and Club Mosses
-Ancient
-grew tall
Ferns
-many places
-relatively small
-2 part life cycle
-gametophyte
-sporophyte
-have rhizomes
-underground stem
-produces fronds (leaves)
-young fronds
-called fiddleheads
-edible
Horsetails
-only 15 species surviving
-small, vascular
-grow in wet, marshy places
-hollow stems
-contain silica
-feel gritty
-called "scouring rushes"
(pioneers)
-used to scrub pots and
pans
Club Mosses
-grow in
woodlands
-not actually
mosses
-have vascular
tissue
Importance of Seedless Vascular
1. help form soil
2. prevent erosion
3. ferns
-houseplants
-fiddleheads = eaten
4. remains of ancient plants form coal
Review Questions
1. What's the difference between a rhizoid and a
rhizome?
A rhizoid is a threadlike extension of cells that
anchors a moss to the ground. A rhizome is the
underground stem of a fern.
2. Describe the ecological importance of mosses
and liverworts.
They can grow in areas that previously had no
plants. When they die, they form a thin soil in
which other plants can grow.