Buds and Leaves
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Transcript of Buds and Leaves
Buds and LeavesBuds and Leaves
UnderstandingUnderstanding
VegetativeVegetative
MorphologyMorphology
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.
Axillary BudsAxillary Buds
Terminal BudTerminal Bud
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
Generalized Angiosperm StemGeneralized Angiosperm Stem
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.
LenticelsLenticels
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.
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!
Leaf ArrangementsLeaf Arrangements
Generalized Angiosperm LeafGeneralized Angiosperm Leaf
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.
Bifacial LeafBifacial LeafPopulus albaPopulus alba L. L.
Adaxial or upper surface Abaxial or lower surface
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.
Axillary BudsAxillary Buds
Leaf ExamplesLeaf Examples
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
Compound Leaf ExamplesCompound Leaf Examples
Margin Patterns and Leaf Margin Patterns and Leaf ShapesShapes
Leaf ShapesLeaf Shapes
Leaf MarginsLeaf Margins
As viewed from the sideAs viewed from the side
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.
Venation PatternsVenation Patterns
Percurrent or Percurrent or scalariformscalariform
LadderlikeLadderlike
ReticulateReticulate NetlikeNetlike
Pinnate VenationPinnate Venation
Pinnate means ‘feather-like’Pinnate means ‘feather-like’
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.
Leaf Apex ShapesLeaf Apex Shapes
Leaf Base ShapesLeaf Base Shapes
Leaf TextureLeaf Texture
Membranous Membranous – very thin– very thin ChartaceousChartaceous – papery in texture – papery in texture
CoriaceousCoriaceous – very thick – very thick
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.
Selected Features of HairsSelected Features of Hairs
Liriodendron tulipiferaLiriodendron tulipifera L. L.
Simple leafSimple leaf Pinnate venationPinnate venation Truncate apexTruncate apex Cordate baseCordate base Long-petioledLong-petioled LobedLobed
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
ColeusColeus x x hybridushybridus Voss. Voss.
Simple leafSimple leaf Margins serrateMargins serrate Acute apexAcute apex Obtuse baseObtuse base Pinnate venationPinnate venation
Ricinus communisRicinus communis L. L.
Simple leafSimple leaf Palmately veinedPalmately veined PeltatePeltate Long-petioledLong-petioled 5-11 lobed5-11 lobed
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.
AmorphaAmorpha L. L.
Leaves odd-pinnateLeaves odd-pinnate Many leafletsMany leaflets Leaflets entireLeaflets entire Compound leavesCompound leaves
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
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.
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.
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
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