Plants without seeds

Chapter 8, section 2

Key concepts

What characteristics do the three groups of nonvascular plants share

What characteristics do the three groups of seedless vascular plants share?

Introduction

Imagine you are hiking in the forest. You see many ferns along the trail. You walk a little father and stop to rest near a stream. Here you see mosses everywhere=on the forest floor on rocks and along the banks of the stream. Although ferns and mosses look very different, they have something in common. They reproduce without forming seeds.

Nonvascular Plants

Three major groups of nonvascular plants Mosses Liverworts and hornworts They are low growing plants that live in moist

areas where they can absorb water and other nutrients directly from their environment

Mosses

Green, fuzzy in the gametophyte generation

Rhizoids anchor the moss and absorb water and nutrients from the soil

Liverworts

Grow on a thick crust of moist rocks or soil along the sides of a stream

Hornworts

Seldom found on tree trunks or rocks, live in moist soil, mixed in with grass plants

Seedless vascular plants

Among the plants were huge, tree-sized ferns as well as trees with branches that grew in a series of circles along the trunk. Other trees resembled giant sticks with leaves up to one meter long. When the leaves dropped off, they left diamond-shaped scars. These tall odd-looking trees were the ancestors of three groups of plants that are alive today-ferns-horsetails, and club mosses. They are seedless plants that have vascular tissue

Characteristics of seedless vascular plants

Do not produce seedsReproduce by producing sporesVascular plants grow tallStrong cell walls providing strength and

stabilityNeed to grow in moist surroundings in

order for gametophytes produce egg cells and sperm cells

Ferns

Underground root system

Horsetails

Long, coarse, needlelike branches grow in a circle around each joint

Stems contains silicaDuring colonial times, Americans used the

plants to scrub their pots and pans

Club Mosses

Club mosses have vascular tissueGrow in moist woodlands and near

streams

1. Which part of plant look like roots

rhyzoids

2. Which parts look like true stems and leaves

Green stem like and leaf like structures

3. Why do scientists call these moss parts roots, stems and leaves?

They do not have transport tissue as true roots, stems and leaves do

4. How are mosses and other nonvascular plants limited by their lack of vascular tissue?

They do not grow very because they cannot transport water as far and as fast as is needed for a tall plant to survive

5. How are these plants similar to most larger plants today?

They have vascular tissue

6. What structures give these seedless plants strength and stability?

Vascular tissue

7. Why is moisture important for reproduction in seedless vascular plants?

Sperm must swim through water to the eggs

8. What advantage is the cuticle to the plant?

It helps prevent water loss from the plant

9. What two characteristics do mosses, liverworts, and hornworts share?

They are low growing and live in moist environments where they can absorb water and nutrients directly from their environment

10. What two characteristics do ferns horsetails and club mosses share?

Vascular tissue and the use of spores to reproduce