Transcript VEGETATIVE MORPHOLOGY

VEGETATIVE
MORPHOLOGY
The Life Span of an Individual Plant
• Annual – Lives for a single growing
season.
• Biennial – Lives for two seasons, growing
vegetatively during the first and flowering
in the second.
• Perennial – Lives for three or more years
and usually flowers and fruits repeatedly.
Plant Habit
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Herb
Subshrub (Suffrutescent plant)
Shrub
Tree
Succulent
Vine
Liana
Epiphyte
Herb
Helianthus maximiliani Schrad.
Subshrub
Gutierrezia sarothrae
Shrub
Artemisia tridentata
Tree
Sequoia sempervirens
Succulent
Cactaceae
Vine
Convolvulus arvensis L.
Liana
Parthenocissus inserta
Epiphytes
Orchids, bromeliads,and others
Roots
• Usually cylindrical plant axes that lack
external nodes and buds. Branch roots
arise from the interior of other roots.
Usually the portion of a plant that absorbs
water and minerals. Most commonly,
roots are underground structures, but
some plants produce above-ground roots.
Types of Roots
• Adventitious – From stem or leaf tissue
rather than the interior of another root.
• Fibrous – With all portions of the root
system of more or less equal thickness,
often well branched, and the primary root
(taproot) absent or not obvious.
• Taproot – The major root, usually
enlarged and growing downward.
Other Types of Roots
• Aerial – Growing above ground or water.
• Fleshy – Thick with water or carbohydrate
storage tissue.
• Haustorial – Specialized for penetrating
other plants and absorbing water and
nutrients from them (as in parasites).
Stem Types
• Aerial stem – Prostrate to erect aboveground stems. These are the most
commonly encountered types of stems.
• Rhizome – Elongated, underground
horizontal stem.
• Stolon – Above ground, horizontal stems
called runners.
More Stem Types
• Bulb – An underground stem with many
fleshy scale leaves filled with stored food.
• Corm – A solid underground stem in which
food is stored.
• Tuber – A much enlarged, short, fleshy,
underground stem.
More Stem Types
• Bulb – An underground stem with many
fleshy scale leaves filled with stored food.
• Corm – A solid underground stem in which
food is stored.
• Tuber – A much enlarged, short, fleshy,
underground stem.
Stem Features 1/4
• Node – The position on a stem where a
leaf was or is attached.
• Internode – The part of a stem axis
between two nodes.
• Axil – The upper angle formed by a leaf
and the twig to which the leaf is attached.
Typically, an auxillary bud (lateral bud)
forms in each leaf axil.
Stem Features 2/4
• Bud – An external meristem (either naked
or protected by bud scales) found on
stems. A bud may give rise to a leafy
stem, a flower or a combination of
vegetative and reproductive structures.
• Axillary bud – A bud borne in the axil of a
leaf; a lateral bud.
• Terminal bud – A bud borne at the end of
a stem.
Stem Features 3/4
• Bud scales – Scale leaves that cover and
protect terminal and axillary buds.
• Bud scale scars – The rough places or
scars left on a stem when bud scales fall
off.
• Stipule scars – A pair of rough places or
scars (or sometimes a single ring-like
scar) left when stipules fall from a twig.
Stem Features 4/4
• Leaf scar – The rough place or scar left
when a leaf falls from a twig. Leaf scars
contain one or more dot-like scars called
vascular bundle scars. The pattern of
bundle scars along with the shape of the
leaf scar can sometimes be used to
determine the species of the plant.
More About Stems
• Acaulescent – Having an inconspicuous
stem.
• Caulescent – Having a distinct stem.
• Woody – Hard in texture, containing
secondary xylem, and persisting for more
than one growing season.
• Twining – Spiraling around a support in
order to climb.
Thorns, spines, prickles
• Thorn – A reduced, sharp-pointed stem.
• Spine – A reduced, sharp-pointed leaf or
stipule or sharp-pointed marginal tooth.
• Prickle – A sharp-pointed hair or
emergence.
Gleditsia triacanthos
Thorns
Opuntia sp.
Example of Spines
Rosa sp.
Example of prickles