Plant Anatomy
and Physiology
Just the Concepts
PLANT CLASSIFICATION
• Explain systems used to classify plants;
• Compare and contrast the hierarchical classification of
agricultural plants; and
• Classify plants according to life cycles, plant use, and
status as monocot or dicot.
Objectives
• What are some ways that we could classify plants?
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Classification Systems
• Taxonomy: the science of classification
• To classify into ordered categories
Classification Systems
• Why Classify?
• Carolus Linnaeus (1707-1778)
• Swedish botanist / physician that
collected plants for their curative
properties needed to organize his
collection.
• Contributed to the development of our
modern system of taxonomy.
• Developed binomial nomenclature, a
two-word naming system still used today.
Carl
Classification Systems
• Botanical Classification
• DKPCOFGS
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Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Classification Systems
Classification Systems
• Mode of Reproduction
• Sexual
• Develop from a seed or spore after the union of male and
female gametes
• Gametes: Sex cells
• Asexual
• Reproduce by vegetative means without sexual gametes
Classification Systems
• Mode of Pollination
• Naturally self-pollinated
• Pollen and embryo sac are produced in the same floral structure
or different flowers on the same plant
• Naturally cross-pollinated
• Pollen transferred from one flower to another flower of a
different plant
• Both self- and cross-pollinated
• Largely self-pollinated, but a some cross-pollination will occur
Classification Systems
• Life Cycle
• Annual
• Plants germinate, grow, flower, produce seed, and die all in one
season
• Biennial
• Requires two growing seasons to complete its life cycle
• The first accumulating food reserves; the second producing
reproductive parts
• Perennial
• Plant that lives indefinitely; produces seeds year after year
Classification Systems
• Growth Habit
• Herbs
• Succulent plants with self-supporting stems
• Vines
• Herbaceous climbing, or twining plants without self-supporting stems
• Lianas
• Woody climbing or twining plants that require other plants for vertical
support
• Shrubs
• Small tree-like plants generally less than 15 feet tall; produce several
trunks from the base
• Trees
• Plants with continuous growth and a large development of woody tissue;
single, distinct stem; more than 15 feet tall
Classification Systems
• Leaf Retention
• Evergreen
• Maintain their leaves throughout the year
• Deciduous
• Naturally shed their leaves annually for extended periods
Classification Systems
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Ecological Adaptation or Habitat
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Epiphyte
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Halophyte
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Adapted to low light conditions
Terrestrial
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Grow in decaying matter and have no green tissue
Sciophyte
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Grows on another plant and takes its nourishment from that plant
Saprophyte
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Adapted to growing in moderate conditions (most of the plants that we know)
Parasite
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Grow in rocks or rocky terrain
Mesophyte
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Grow in water or in waterlogged soil
Lithophyte
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Can grow in high salt conditions
Hydrophyte (Aquatic)
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Grow above ground on another plant for vertical support; not a parasite
Grows on land with roots under ground absorbing water and a shoot above ground (most of the
plants that we know
Xerophyte
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Adapted to grow in areas with little or no water
Classification Systems
• Flowering vs. Non-Flowering
• Flowering plants produce seeds
• Seed Parts (Cotyledons)
• Monocot
• Dicot
Classification Systems
• Monocot
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Embryo with one Cotyledon
Pollen with one furrow or pore
Flower parts in multiples of three
Major leaf veins are parallel
Vascular bundles are scattered in the stem
Roots are adventitious
• Dicot
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Embryo with two cotyledons
Pollen with three furrows or pores
Flower parts in multiples of four or five
Major leaf veins are netted
Vascular bindles are a ring in the stem
Roots develop from a radicle
Classification Systems
• Crops vs. Weeds
• Crop
• A useful plant grown for a specific purpose
• Used by humans directly or indirectly, raw or processed
• Intentionally grown and managed
• Weed
• Any plant growing where it is not wanted
• Competes with the intended plant for space, light, nutrients,
and water
Agricultural Classification
• Agronomic Crops vs. Horticultural Crops
• Agronomic (Field Crops)
• Mostly annual, herbaceous plants grown under extensive or
large-scale culture
• Usually dried and processed prior to use
• Horticulture crops
• Annual and perennial plants grown under intensive culture
• Intensive: large input of capitol, labor, and technology per acre
• High moisture content, spoil quickly
• Used for food, medicine, beauty
Agricultural Classification
• Could some plants be classified in several groups?
• Which ones?
Agricultural Classification
• We have got to have some order
• We base most classifications on Primary Use rather than
on the other minor uses
Agricultural Classification
Agricultural Classification