Buds and Leaves

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Buds and Leaves Buds and Leaves Understanding Understanding Vegetative Vegetative Morphology Morphology

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Buds and Leaves. Understanding Vegetative Morphology. Buds. Buds are short embryonic stems. In angiosperms, buds are found at the nodes, in the leaf axil, or at the end of a stem. Buds are especially useful for identifying twigs in winter condition. - PowerPoint PPT Presentation

Transcript of Buds and Leaves

Page 1: Buds and Leaves

Buds and LeavesBuds and Leaves

UnderstandingUnderstanding

VegetativeVegetative

MorphologyMorphology

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BudsBuds

Buds are short embryonic stems.Buds are short embryonic stems. In angiosperms, buds are found at the nodes, In angiosperms, buds are found at the nodes,

in the leaf axil, or at the end of a stem. in the leaf axil, or at the end of a stem. Buds are especially useful for identifying Buds are especially useful for identifying

twigs in winter condition.twigs in winter condition. Buds are protected by bud scales, a dense Buds are protected by bud scales, a dense

covering of hairs, and/or a sticky secretion.covering of hairs, and/or a sticky secretion.

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Axillary BudsAxillary Buds

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Terminal BudTerminal Bud

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Bud TypesBud Types

Accessory BudAccessory Bud Axillary BudAxillary Bud Flower BudFlower Bud Leaf BudLeaf Bud Mixed BudMixed Bud Naked BudNaked Bud Pseudoterminal BudPseudoterminal Bud Superposed BudSuperposed Bud Terminal BudTerminal Bud

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Generalized Angiosperm StemGeneralized Angiosperm Stem

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Lenticels and Leaf ScarsLenticels and Leaf Scars

Lenticels are breathing pores in the young bark Lenticels are breathing pores in the young bark of a woody stem. Scattered lenticels dot the of a woody stem. Scattered lenticels dot the stem between leaf scars.stem between leaf scars.

Leaf scars remain on a stem after the leaves Leaf scars remain on a stem after the leaves have fallen. The circles within each scar are have fallen. The circles within each scar are the severed ends of food and water-conducting the severed ends of food and water-conducting bundles. bundles.

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LenticelsLenticels

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Leaf DurationLeaf Duration

Leaves may function from a few days to many Leaves may function from a few days to many years, but most leaves function for only one or years, but most leaves function for only one or two growing seasons.two growing seasons.

DeciduousDeciduous leaves fall at the end of the leaves fall at the end of the growing season.growing season.

EvergreenEvergreen plants are leafy throughout the plants are leafy throughout the year.year.

Marcescent Marcescent leaves wither but do not fall leaves wither but do not fall during the winter or dry season.during the winter or dry season.

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Marcescent LeavesMarcescent Leaves

Many oaks, beeches, Many oaks, beeches, and hornbeams are and hornbeams are marcescentmarcescent. This may . This may be an adaptation to be an adaptation to protect winter buds protect winter buds from browsing animals. from browsing animals. The dried leaves The dried leaves remaining on the plant remaining on the plant are not very tasty!are not very tasty!

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Leaf ArrangementsLeaf Arrangements

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Generalized Angiosperm LeafGeneralized Angiosperm Leaf

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Upper and lower leaf surfacesUpper and lower leaf surfaces

UnifacialUnifacial leaves lack any differentation leaves lack any differentation between adaxial (upper) and abaxial (lower) between adaxial (upper) and abaxial (lower) leaf surfaces.leaf surfaces.

Bifacial Bifacial leaves have definite differences leaves have definite differences between adaxial (upper) and abaxial (lower) between adaxial (upper) and abaxial (lower) leaf surfaces.leaf surfaces.

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Bifacial LeafBifacial LeafPopulus albaPopulus alba L. L.

Adaxial or upper surface Abaxial or lower surface

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Leaf StructureLeaf Structure

A leaf with a single blade is termed A leaf with a single blade is termed simple.simple. A leaf with two or more blades, or A leaf with two or more blades, or leafletsleaflets, is , is

said to be compoundsaid to be compound..

The distinction between simple and compound The distinction between simple and compound leaves can be made by locating an axillary leaves can be made by locating an axillary bud: an axillary bud is subtended by the entire bud: an axillary bud is subtended by the entire leaf and never by individual leaflets. leaf and never by individual leaflets.

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Axillary BudsAxillary Buds

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Leaf ExamplesLeaf Examples

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Simple and Compound LeavesSimple and Compound Leaves

Simple LeavesSimple Leaves a. Pinnate Venationa. Pinnate Venation b. Palmate Venationb. Palmate Venation c. Parallel Venationc. Parallel Venation Compound LeavesCompound Leaves d. Pinnately Compoundd. Pinnately Compound e. Bi-pinnately e. Bi-pinnately

CompoundCompound f. Palmately compoundf. Palmately compound

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Compound Leaf ExamplesCompound Leaf Examples

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Margin Patterns and Leaf Margin Patterns and Leaf ShapesShapes

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Leaf ShapesLeaf Shapes

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Leaf MarginsLeaf Margins

As viewed from the sideAs viewed from the side

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Venation TypesVenation Types

Primary vein (midvein)Primary vein (midvein) The one most prominent vein in the leaf.The one most prominent vein in the leaf. Secondary veinsSecondary veins Veins that branch from the primary vein.Veins that branch from the primary vein. Tertiary veinsTertiary veins Veins that link the secondaries.Veins that link the secondaries.

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Venation PatternsVenation Patterns

Percurrent or Percurrent or scalariformscalariform

LadderlikeLadderlike

ReticulateReticulate NetlikeNetlike

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Pinnate VenationPinnate Venation

Pinnate means ‘feather-like’Pinnate means ‘feather-like’

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Palmate VenationPalmate Venation

Arise from one point at the tip of the petiole, like Arise from one point at the tip of the petiole, like fingers of an outstretched hand.fingers of an outstretched hand.

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Leaf Apex ShapesLeaf Apex Shapes

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Leaf Base ShapesLeaf Base Shapes

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Leaf TextureLeaf Texture

Membranous Membranous – very thin– very thin ChartaceousChartaceous – papery in texture – papery in texture

CoriaceousCoriaceous – very thick – very thick

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Surface Texture TermsSurface Texture Terms

Glabrous – lacking hairs.Glabrous – lacking hairs. Pubescent – with various hairs.Pubescent – with various hairs.

Glaucous – with a waxy covering.Glaucous – with a waxy covering. Other Terms:Other Terms:

Arachnoid, canescent, hirsute, hispid, lanate, Arachnoid, canescent, hirsute, hispid, lanate, pilose, puberulent, scabrous, sericeous, pilose, puberulent, scabrous, sericeous, strigose,tomentose,velutinous, villous.strigose,tomentose,velutinous, villous.

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Selected Features of HairsSelected Features of Hairs

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Liriodendron tulipiferaLiriodendron tulipifera L. L.

Simple leafSimple leaf Pinnate venationPinnate venation Truncate apexTruncate apex Cordate baseCordate base Long-petioledLong-petioled LobedLobed

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Lonicera sempervirensLonicera sempervirens L. L.

Perfoliate upper leavesPerfoliate upper leaves Ovate to oblongOvate to oblong Glaucous beneath on Glaucous beneath on

abaxial surfaceabaxial surface Simple leavesSimple leaves

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ColeusColeus x x hybridushybridus Voss. Voss.

Simple leafSimple leaf Margins serrateMargins serrate Acute apexAcute apex Obtuse baseObtuse base Pinnate venationPinnate venation

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Ricinus communisRicinus communis L. L.

Simple leafSimple leaf Palmately veinedPalmately veined PeltatePeltate Long-petioledLong-petioled 5-11 lobed5-11 lobed

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Gymnocladus dioicaGymnocladus dioica

Bi-pinnately compound Bi-pinnately compound leafleaf

Leaflets entireLeaflets entire Pinnae in 3-7 pairsPinnae in 3-7 pairs Larger terminal ones Larger terminal ones

with 3-7 pairs of ovate, with 3-7 pairs of ovate, acute leaflets to 3 inches acute leaflets to 3 inches long.long.

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AmorphaAmorpha L. L.

Leaves odd-pinnateLeaves odd-pinnate Many leafletsMany leaflets Leaflets entireLeaflets entire Compound leavesCompound leaves

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Populus albaPopulus alba L. L.

Simple leafSimple leaf Long petioledLong petioled Palmate venationPalmate venation Lobed Lobed Rounded or slightly Rounded or slightly

cordatecordate Truncate baseTruncate base

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Taraxacum officinaleTaraxacum officinale

Leaves simpleLeaves simple Leaves oblong, Leaves oblong,

spatulate, or spatulate, or oblanceolate.oblanceolate.

Nearly entire to sinuate-Nearly entire to sinuate-pinnatifid.pinnatifid.

Terminal segment Terminal segment largest. largest.

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Pinus ponderosaPinus ponderosa

Leaves linearLeaves linear Leaves needle shapedLeaves needle shaped Leaves usually in Leaves usually in

fascicles of 3.fascicles of 3. 5 to 11 inches long.5 to 11 inches long.

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Cercis canadensisCercis canadensis L. L.

Leaves simpleLeaves simple Leaves entireLeaves entire Palmately veined.Palmately veined. Leaves broadly ovate to Leaves broadly ovate to

nearly orbicular.nearly orbicular. Cordate at base.Cordate at base. Attenuate at apexAttenuate at apex

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Quercus macrocarpaQuercus macrocarpa Michx. Michx.

Leaves obovateLeaves obovate Leaves simpleLeaves simple Leaves pinnatifid with Leaves pinnatifid with

large terminal lobe.large terminal lobe. Grayish-pubescent Grayish-pubescent

abaxial surface.abaxial surface. DeciduousDeciduous