Lesson 1 What is a plant?
Lesson 2 Seedless Plants
Lesson 3 Seed Plants
Plant Classification
Plants
Non
Vascular
Mosses
Vascular
Seedless
(Spores)
Seed
• One way to classify
plants is:
Non
Ferns
Flowering
Flowering
non-vascular
and
vascular
plants.
Gymnosperms
Angiosperms
Plant Classification
Plants
Non
Vascular
Mosses
Vascular
Seedless
(Spores)
Ferns
Seed
Non
Flowering
Flowering
Gymnosperms
Angiosperms
Non-vascular Seedless Plants
• Non-vascular plants are called
bryophytes, they have no vascular
tissue, no true seeds, roots, stems or
leaves.
• Because they lack vascular tissue,
the bryophytes usually live in moist
environments, they use diffusion and
osmosis for nutrient transport.
• Instead of roots, they have rhizoids.
• Instead of stems, they have stalks.
Non-vascular Seedless Plants (cont.)
• Examples of non-vascular plants are
mosses, liverworts, and hornworts.
• Mosses, the most common bryophytes,
are small, green plants that usually grow
in shady, damp environments.
Plant Classification
Plants
Non
Vascular
Mosses
Vascular
Seedless
(Spores)
Ferns
Seed
Non
Flowering
Flowering
Gymnosperms
Angiosperms
Vascular Seedless Plants
• Over 90 percent of plant species are
vascular plants which contain vascular
tissue in their roots, stems and leaves.
• There are two kinds of vascular plants:
seedless and seed plants.
Plant Classification
Plants
Non
Vascular
Mosses
Vascular
Seedless
(Spores)
Ferns
Seed
Non
Flowering
Flowering
Gymnosperms
Angiosperms
Vascular Seedless Plants
• Examples of vascular seedless plants
are ferns, club mosses and horsetails
that reproduce using spores.
Vascular Seedless Plants (cont.)
• The fronds, or leaves of ferns, make up
most of a fern.
• Ferns grow
in a variety
of habitats,
including
damp, swampy
areas and dry,
rocky cliffs.
Steven P. Lynch
Vascular Seedless Plants (cont.)
Unlike mosses, club mosses have roots,
stems, and leaves.
Steven P. Lynch
Vascular Seedless Plants (cont.)
• Horsetails have
small leaves
growing in circles
around the stems.
• Horsetail stems
are hollow, and the
tissues contain
silica, a mineral in
sand, that makes
them abrasive.
S. Solum/PhotoLink/Getty Images
Plant Classification
Plants
Non
Vascular
Mosses
Vascular
Seedless
(Spores)
Ferns
Seed
Non
Flowering
Flowering
Gymnosperms
Angiosperms
Vascular Seed Plants
• There are two kinds of vascular seed
plants: non-flowering gymnosperms
and flowering angiosperms.
Quarto, Inc./Photodisc/Getty Images
Steven P. Lynch
Plant Classification
Plants
Non
Vascular
Mosses
Vascular
Seedless
(Spores)
Ferns
Seed
Non
Flowering
Flowering
Gymnosperms
Angiosperms
Gymnosperms
• Non-flowering
gymnosperms
produce seed in a
cone.
• Examples
of gymnosperms
include conifers,
cyads, ginkoes,
and gnetophytes.
Siede Preis/Getty Images
Plant Classification
Plants
Non
Vascular
Mosses
Vascular
Seedless
(Spores)
Ferns
Seed
Non
Flowering
Flowering
Gymnosperms
Angiosperms
Angiosperms (cont.)
• Flowering
angiosperms
produce seeds in a
fruit, fruits grow from
flowers.
CORBIS
Angiosperms
• There are more than 260,000 species
of flowering plants, or angiosperms.
• Almost all of the food eaten by humans
comes from angiosperms or from
animals that eat angiosperms.
Characteristics of Seed Plants (cont.)
• All seed plants have vascular tissue,
roots, stems, and leaves.
Characteristics of Seed Plants (cont.)
• There are two types of vascular tissue:
xylem that carries water and nutrients,
from roots to leaves and phloem that
carries sugar from leaves to everywhere
else.
Characteristics of Seed Plants (cont.)
• Roots anchor a plant, either in soil or
onto another plant or an object such as
a rock.
• All root systems help a plant absorb
water and other substance from the soil.
Characteristics of Seed Plants (cont.)
• The part of a plant that connects its roots
to its leaves is the stem.
• Stems support branches and leaves,
and their vascular tissues transport
water, minerals, and food.
• Plant stems are usually classified as
either herbaceous, which are usually
soft and green, or woody, which are stiff
and typically not green.
Dr. Gerald Van Dyke/Visuals Unlimited/Getty Images
• The top and bottom surface of leaves
consists of epidermal tissue coated by a
layer of cuticle to prevent water loss,
and embedded by stomata to allow
water evaporation and gas exchange.
Characteristics of Seed Plants (cont.)
Below the upper epidermis are rows of
tightly packed cells called palisade
mesophyll cells where photosynthesis
mainly occurs.
Angiosperms (cont.)
• There are three kinds of growth
methods: annual, biennials, and
• Plants that grow, flower, and produce
seeds in one growing season are called
annuals.
Angiosperms (cont.)
• Biennials complete their life cycles in
two growing seasons.
• During the first year, the plant grows
roots, stems and leaves.
• In the second growing season the plant
produces new stems, leaves, flowers,
and seeds.
Angiosperms (cont.)
• Perennial plants, like trees and shrubs,
can live for more than two growing
seasons.
• Flowering plants are organized into two
groups—monocots and dicots.
• These groups are based on the number
of leaves in early development, or
cotyledons, in a seed.