Classifying and Identifying Plants
Classifying and Identifying Plants
Introduction to Plant
Science & Plant
The basic industry of agriculture is
dependant on plants.
The animal grower needs many kinds of
plants to feed livestock.
The plant industry needs superior plants
that are productive and resistant to
insects, disease, and drought.
Plants are needed for landscaping the
inside and outside of homes & office
Wildlife are dependant upon plants for
food and shelter.
Careers involving plants
Plant scientists: Plant breeders develop new
varieties with improved traits of economically
Agronomists specialize in the production &
cultivation practices of plants for food and
fiber. They understand soils, irrigation
practices, planting & harvesting practices
fertilizers, insects & pesticides.
Horticulturalists produce ornamental plants in
greenhouses & nurseries that used in homes,
offices and landscapes. They specialize in
flowers, trees, shrubs, and turf grass.
Careers involving plants
Foresters grow, manage and harvest trees
for lumber, poles, posts, and pulpwood.
Range managers, manage water sheds,
wetlands and rangeland used for grazing,
both livestock and wildlife.
There are literally hundreds of careers
that are either directly or indirectly
associated with plants and require a basic
understanding of plants.
There are many different types of plants and ways
of classifying them.
In the scientific Taxonomy system of classification.
There are two major kingdoms. Plants & Animals.
The plant kingdom is divided into four divisions or
1. Algae & Fungi
2. Green plants without roots or flowers like
mosses & Lichens
3. Green plants with vascular tissue, true roots,
distinct leaves and stems but no true flowers or
seeds & they reproduce by means of spores on
the backs of the leaves like ferns.
4. Plants which have true flowers and produce
seeds. (The majority of our agriculture crops.)
This 4th Division is refered to as
Spermatophyta and are your seed producing
plants. There are two classes of plants within
Gymnosperms are most of your cone bearing
trees. (Used to harvest lumber)
Angiosperms are those species that have
flowers and seeds always protected by a
Most of our food producing crops are Angiosperms.
Angiosperms have to main divisions
Monocotyledons or (Monocots) 1 Cotlyledon
Dicotlyledons or (Dicots) 2 cotlyedons
A Cotyledon is the first leaf that emerges from a
Broad leaf plants have two cotyledons and are
refered to as Dicots. (Peas, Beans, alfalfa,
Tomatoes, most weeds)
Monocots make up all of the grasses, and cereal
grains (Corn, wheat, barley, oats, ext.)
Plants are also sometimes classified by their life
Plant life cycles.
Annual: Plants start from seed, produce seed
and die in one year.
Biennial: Plants live two years, sprouting from
seed the first year and grows leaves, stems &
roots. The second year the plants produce
seed and die after the seed matures. Many
broad leaf weeds are considered biennials.
Perennial; Plants live three or more years.
Each year new stems grow from the crowns.
Perennial plants have deep root systems.
Alfalfa and the majority of Montana’s range
plants are perennials.
Plant Growth Season
Plants are also classified based on their
season of growth.
Cool Season Plants: Grow best and flower
during the spring and early summer when
weather conditions are cool. These plants
may grow again in the fall if temperatures
and moisture conditions are ideal.
Warm Season Plants: Warm Season plants
grow and flower in the mid to late summer.
Evergreens: Perennial plants that have green
leaves the entire year.
Deciduous: Plants that loose there leaves
Cool Season Plants
Cool and warm season plants have different
Cool season plants originate in cooler regions
of the earth and have a C3 photosynthetic
process. In comparison to warm season
plants, cool season plants are less efficient at
gathering carbon dioxide and using water.
Optimum temperature for cool season plants is
a cool 65 to 75 degrees. These plants are most
productive in early spring and late fall.
Most of the range plants in Montana are cool
Warm Season Plants
Warm Season plants originated in tropical
conditions and have a C4 photosynthetic
process. Warm season plants are very
efficient at gathering and processing
carbon dioxide and water.
Ideal temperature for warm season plants
is 90 to 95 degrees. These plants are
most productive in the hot summer
months. Many of today’s noxious weeds
are warm season plants.
Plant Identification & Anatomy
Regardless of class or type, all plants have
four basic physiological structures that
influence plant growth and are important
in plant identification.
Seed head / Flowers
The largest part of the plant is the root system. The
roots take up more space in the soil than does the top
part of the plant seen in the air above the ground.
Some roots may extend, 6,8 even 10 ft into the soil.
Roots anchor the plant to the soil. They provide plants
with water and minerals that are absorbed from the
Healthy plants have healthy roots.
There are two main types of root systems.
Leaves are the food factories of the plant.
Undergo Photosynthesis and use sunlight,
water and carbon dioxide to build
carbohydrates for growth and release
Several aspects of the leaf are used to
identify the type of plant.
There are two basic types of leafs: Simple
Simple leaves have a single leaf blade
generally with a petiole attached to the
main plant stem.
Compound leaves have secondary, small
leaves, called leaflets, attached to each leaf
stalk. The leaf stalk is connected to the
Simple & Compound Leaves
Leaf veins also fall into three categories.
Parallel: Veins run up and down (vertical)
and are spaced equally apart.
Pinnate: Veins are attached to the main
(central) vein at many different points.
Palmate: Veins are attached at the base of
the main (Central) vein.
The function of the plant stem is to hold
the plant upright and through various
vascular tissues, (xylem & phloem)
transport water and minerals and food
through out the plant.
Another name for plant stems are plant
Plant Stem Growth Forms
Plant Seed head / Flowers
The seed head ultimately produces genetic
material for reproduction.
Another name for the seed head is an
parts to a plant