chapter 8 section 2 plants without seeds. nonvascular plants three major groups of nonvascular...

C H A P T E R 8 S E C T I O N 2

PLANTS WITHOUT SEEDS

NONVASCULAR PLANTS

• Three major groups of nonvascular plants

• Mosses

• Liverworts

• Hornworts

CHARACTERISTICS OF NONVASCULAR PLANTS

• Low-growing

• Live in moist environments

• Absorb water and other nutrients directly

• Watery surroundings enable sperm cells to swim to egg cells

MOSSES

10,000 species • Green, fuzzy moss is the gametophyte

generation of the plant

• Rhizods: thin, rootlike structures that anchor the moss and absorb water and nutrients from the soil

• The sporophyte generation grows out of the gametophyte

• The sporophyte consists of a slender stalk with a capsule at the end

• The capsule contains spores

A MOSS PLANT

LIVERWORTS

8,000 species

• Often found growing as a thick crust on moist rocks or soil along the sides of a stream

HORNWORTS

• Fewer than 100 species

• Live in moist soil, often mixed in with grass plants

SEEDLESS VASCULAR PLANTS

• Characteristics• Ferns, club mosses and horsetails have true vascular

tissue

• Do not produce seeds, these plants reproduce by releasing spores

• Can grow tall because vascular tissues effectively transport materials

• Provide strength and stability

• Grow in moist environments• There must be enough water for the

sperm to swim to the eggs

FERNS

• Stems of most ferns grow underground

• Fronds• Fern leaves, divided into many

smaller parts that look like small leaves

• The cuticle is found on the upper surface of each frond, helps retain plant water

• Tiny spore cases are found on the underside of the fronds

HORSETAILS

• Seedless, vascular plant

• Stems are jointed

• Long, coarse, needle-like branches

• Resemble a horse’s tail

• Silica• Stem contains a gritty

substance also found in sand

CLUB MOSSES

• Seedless, vascular plant

• Not to be confused with moss

• Grow in moist woodlands and near streams