Raunkiaer`s classification

Raunkiaer’s classification
Raunkiaer’s classification is a
system published by Christen
Raunkiaer in 1934 to describe
plant life forms.
It is based on the location of the
buds on the plant and the way the
resting bud survives periods of
adverse conditions – like cold or
drought.
It is a useful way to relate plant
and environmental interactions.
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Modified Raunkiaer classification
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Phanerophyte
Chamaephyte
Hemicryptophyte
Cryptophyte
• Geophyte
• Helophyte
• Hydrophyte
• Therophyte
• Epiphyte
• Aerophyte
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Raunkiaer’s classification
Phanerophytes are the woody
perennials (trees and shrubs).
The resting buds are > 0.5 m
above ground.
Phanerophytes have been further
subdivided based on the size of
the plants into
megaphanerophytes,
mesophanerophytes and
nanophanerophytes.
Additional modification to this
class recognizes differences in
deciduous and evergreen species.
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Magnolia
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Raunkiaer’s classification
Chamaephytes are woody
perennials with the resting
bud < 0.5 m above the ground.
These include small shrubs.
Bunchberry (Cornus canadensis) and Vaccinium are chamaephytes.
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Raunkiaer’s classification
Hemicryptophytes are herbaceous
perennial plants with the resting
bud at or near the soil line.
Grasses, clover and dandelion are
all hemicryptophytes.
Drabra
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Raunkiaer’s classification
Cryptophytes are
perennial plants where
the resting bud is below
ground including those
below water.
Cryptophytes can be
further subdivided into
geophytes, helophytes
and hydrophytes.
Flowering onion
Iris
Daffodil
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Tulip
Hyacinth
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Raunkiaer’s classification
Cryptophyte
Geophytes have roots or shoots
that are modified as storage
organs.
Geophytes include bulbs, corms,
rhizomes, tubers, tuberous
shoots, and tuberous roots.
Rhizome
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Tuber
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Bulb
Corm
Tuberous stem
Tuberous root
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Raunkiaer’s classification
Cryptophyte
Helophytes are those plants that grow
in wet soils. The resting bud is below
ground in the wet soil.
Marsh marigold (Caltha)
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Cattail (Typha)
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Raunkiaer’s classification
Cryptophyte
Hydrophytes grow in water and resting
bud overwinters below the surface of the
water often in the lake bed floor.
Lotus (Nelumbo nucifera)
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Waterlily (Nymphaea)
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Raunkiaer’s classification
Therophytes are those
plants that survive adverse
climatic conditions as seeds.
These include all of the
annual plants.
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Raunkiaer’s classification
An epiphyte is a plant that grows on
another plant, but does not derive
water or nutrients from the
association.
Epiphytic vascular plants occur
most often in the moist tropics and
include ferns, aroids, orchids,
bromeliads, peperomias, and cactus.
Non-vascular epiphytes include
mosses and lichens.
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Raunkiaer’s classification
Aerophytes are epiphytes, but they
have no functional roots and absorb
moisture and nutrients through their
leaves.
A good example of this type of plant
is Tillandsia.
Tillandsia cyanea)
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Spanish moss (Tillandsia usneoides)
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