Exam 1 Flashcards
Botany
The scientific study of autotrophs, including their physiology, structure, genetics, ecology, distribution, classification, and economic importance
Botany as a science
Originally the study of plants but has come to include autotrophs and fungi (archaebacteria, bacteria, fungi, plantae, and protista)
Diversification of plant study
Plant anatomy, plant physiology, taxonomy, geography, ecology, morphology, genetics, cell biology, and economic botany and ethnobotany
Eight attributes of living organisms
Composition and structure, growth, reproduction, response to stimuli, metabolism, movement, complexity of organization, and environmental adaptation
Cell
Structural units of organisms
Cytoplasm
Interior cell matrix
Nucleus
DNA suspended in cytoplasm
Cell wall
Bounds cytoplasm
Respiration
Energy release
Photosynthesis
Energy harnessing
Digestion
Conversion of large insoluble food molecules to smaller soluble molecules
Assimilation
Conversion of raw materials into cell substances
Cohesion
Attraction of similar molecules (capillary movement in plants)
Adhesion
Attraction of dissimilar molecules
Hydrolysis
Occurs when a hydrogen becomes attached to one monomer and a hydroxyl group to the other. Energy is released, which may be stored temporarily or used in the manufacture or renewal of cell components
Starch
Coils of glucose molecules. Main carbohydrate reserve of plants
Cellulose
Unbranched chain of glucose molecules. Main structural polymer in plant cell walls
Prokaryotic
Cells lack a nucleus (bacteria)
Eukaryotic
Cell contains a nucleus. Plants and animals
Cell walls
Rigid boundary of cells
Organelles
Membrane bound bodies found in eukaryotic cells. Various shapes and sizes with various functions. Not all are bound by membranes
Protoplasm
All components of a living cell
Cytoplasm
All cellular components between the plasma membrane and the nucleus
Cytosol
Fluid within cytoplasm containing organelles
Vacuole
Provides turgor pressure
Microtubule
Conducts intercellular communication
Dictyosome
Plant equivalent of golgi body
Intracellular space
Provides structural support
Middle lamella
Hard when unripe, breaks down when ripening
Hemicellulose
Holds cellulose fibrils together
Pectin
Gives stiffness (like in fruit jellies)
Glycoproteins
Proteins with associated sugars
Plasmodesmata
Cytoplasmic strands that extend between cells through minute openings
Chloroplasts
Most conspicuous plastids, bound by double membrane
Grana
Made up of thylakoids
Thylakoid membranes
Contain chlorophyll. Hosts of first steps of photosynthesis.
Stroma
Matrix of enzymes involved in photosynthesis
Chromoplasts
Other type of plastid. Synthesize and accumulate carotenoids (yellow, orange, red)
Leucoplasts
Colorless plastids, may synthesize starches (amyloplasts) or oils (elaioplasts)
Cristae
Folds of inner mitochondrial membrane
Cell cycle
Orderly series of events when cells divide. Interphase, mitosis, cytokinesis
In telophase in plant cells
Phragmoplast and cell plate form at equator
Cell plate formation
Phragmoplast develops between daughter cell nuclei. Microtubules trap dictyosome derived vesicles. Vesicles fuse to form cell plate. Portions of ER are trapped between vesicles, forming plasmodesmata.
Phragmoplast
Complex of microtubules and ER
Meristematic tissue
Tissue that actively divides (shoots, tips)
Simple tissues
One type of cell
Complex tissues
Two plus types of cell
Four major groups of plant organs
Roots, stens, leaves, and flowers
Meristems
Permanent regions of growth and active cell division
Apical meristem
A meristem at the tip of a root or shoot, which increase in length as the apical meristems produce new cells (= primary growth)
Primary meristem
Develop from apical meristem. Produce primary tissue: protoderm, ground meristem, and procambium.
Lateral meristem
Produce secondary tissues that increase the girth if roots and stems (secondary growth)
Vascular cambium
Produces xylem and phloem (tissues primarily for support and conduction). Composed of a thin cylinder of brick-shaped cells that extends the length of stems and roots
Cork cambium
Lies outside the vascular cambium just inside the outer bark. Produces bark
Intercalary meristems
In vicinity of nodes (leaf attachment area), add to stem length.
Parenchyma
Simple tissue. Thin, pliable walls. Usually 14-sided at maturity. Living cytoplasm, often containing large vacuoles and various secretions. May remain alive a long time. Have spaces between them. Food/water storage/repair.
Aerenchyma
Parenchyma tissue with extensive, connected air spaces, usually in aquatic plants
Chlorenchyma
Parenchyma cells containing chloroplasts that function in photosynthesis
Transfer cells
Develop irregular extensions of inner wall that greatly increases surface area of plasma membrane (nectaries of flowers
Sclerenchyma
Characteristics: thick, tough, lignin infused. Dead at maturity. Function in support.
Sclereids
Stone cells. Scattered in tissue. Cells as long as wide.
Fibers
Much longer than wide and contain lumen (tiny cavity)
Vascular tissues
Complex tissues that include xylem and phloem.
Xylem
Chief conducting tissue for water and minerals that are absorbed by the roots. Composed of parenchyma cells, fibers, vessels, tracheids, and ray cells
Vessels
Made of vessel elements
Vessel elements
Open at each end, but may have a perforation plate. Dead at maturity. Thick secondary cell walls. Many have spiral thickenings on vessel walls.
Tracheids
Tapered at the ends with pairs of pits that allow water to pass from cell to cell. Pits. Dead at maturity. Thick secondary cell wall. May have spiral thickenings on cell walls. Composed of parenchyma cells.
Pits
Areas without secondary cell wall
Rays
Function in lateral conduction and food storage.
Phloem
Complex tissue that moves products of photosynthesis from leaves to other areas of the plant. Sieve tube members (large), sieve cells (smaller), fibers
Sieve tube members (large)
Lack secondary cells and nuclei. Lay end to end to form sieve tubes. Sieve plates with small pores. Callose forms plug, preventing leaks during injury. Companion cells aid in conduction of food.
Sieve cells (smaller)
Ferns and gymnosperms. Lack secondary cell walls and nuclei. Much narrower than sieve tube members. Lay overlapped at ends. Walls have sieve plates with small pores. Albuminous cells.
Albuminous cells
Companion cells aid in conduction
Fibers
Much longer than wide and contain lumen (tiny cavity). High strength
Epidermis
Complex tissue. Protective layer that is one cell layer thick covering all plant organs. Composed mostly of parenchyma cells, guard cells of stomata, secretory glands, and hairs
Cutin
Produced by leaf and stem epidermal cells, a fatty substance on the surface of outer walls of epidermis that forms cuticle
Cuticle
Wax secreted on cuticle, cuticle and wax prevent water loss by evaporation. Resistant to bacteria and other disease organisms
Root hairs
Root epidermis produced. Greatly increases surface area. Increases absorptive area of root surface
Periderm
Replaces epidermis when cork cambium begins producing more tissue. Constitutes outer bark. Primarily cork cells
Cork cells
Dead at maturity. While alive cytoplasm secretes suberin (fatty substance) into walls. Makes cork cells waterproof and helps protect phloem
Lenticels
Loosely arranged pockets of parenchyma cells formed by cork cambium that protrude through the surface of periderm
Secretory cells and tissue
May function individually or as part of a tissue. Flower nectar, citrus oils, glandular hair mucilage, latex, and resins
Function of roots
Anchor plants into soil, absorb water and minerals, and store food and water
Radicle
Emerges at germination and develops into first root
Taproot
Main root with thinner branch roots
Fibrous root system
Many thinner branching roots
Fibrous roots
Large number of fine roots of similar diameter formed adventitiously
Adventitious roots
Do not develop from another root but from a stem or leaf
Régions of the root
Root cap, région of cell division, region of cell elongation, region of maturation
Root cap
Thimble shaped mass of parenchyma cells covering each root tip. Protects tissues from damage as root grows. Secretes mucigel that acts as lubricant. Functions in gravitropism
Région of cell division
Composed if apical meristem in center of root tip. Subdivided into 3 meristematic areas
Protoderm
Area of cell division region that gives rise to epidermis
Ground meristem
Area of cell division region that gives rise to the cortex and pith
Procambium
Area of cell division region that gives rise to primary xylem and primary phloem
Région of elongation
Cells become several times their original length. Vacuoles merge, and movement occurs
Région of maturation
Cells differentiate into various distinctive cell types.
Root hairs form
Epidermal cell extensions with thin cuticle; absorb water and minerals; adhere tightly to to soil particles; increase of total absorptive surface of root
Cortex
Parenchyma cells between epidermis and vascular cylinder. Stores food and water
Endodermis
Inner boundary of cortex, consisting of a single-layered cylinder of compact cells. Cell walls with suberin bands called casparian strips. Eventually inner cell walls become thickened with suberin, except for passage cells
Casparian strips
Forces water and dissolved substances entering and leaving the central core to pass through endodermis. Regulates types of minerals absorbed
Vascular cylinder
Core of tissues inside endodermis. Primary xylem or phloem
Pericycle
Outer boundary of vascular cylinder. Continues to divide, even after maturity. Forms lateral roots and part of the vascular cambium
Dicot and conifer vascular cylinder
Solid core of xylem with arms in cross section. Phloem in patches between xylem arms.
Vascular cylinder
Forms secondary phloem to the outside and secondary xylem to the inside
Monocot vascular cylinder
Xylem surrounds pith
Determinate growth
Growth that stops after an organ is fully expanded or after a plant has reached a certain size
Indeterminate growth
New tissues are added indefinitely (season after season)
Food storage growth
Starch and other carbohydrates. Sweet potatoes
Water storage roots
Pumpkin family, especially in arid regions
Propagative roots
Adventitious buds on roots. Develop into suckers (aerial stems). (Fruit trees, tomatoes)
Pneumatophores
Spongy roots in water, extend above water surface, enhance gas exchange
Aerial roots
In air, not soil
Orchids
Velamen roots with epidermis several layers thick to reduce water loss
Corn
Prop roots support plants in high wind
Ivies (English ivy, Virginia creeper)
Aerial roots aid plants in climbing
Contractile roots
Pull plant deeper into the soil (lily bulbs, dandelions)
Buttress roots
Stability in shallow soil (tropical trees)
Parasitic roots
Plants with no chlorophyll are dependent on chlorophyll bearing plants for nutrition
Mycorrhizae
Mutualistic association, both fungus and root benefit and are dependent on association for normal development. Fungi facilitate absorption of water and nutrients, especially phosphorus for roots. Plant furnishes sugars and amino acids to fungus. Fungus is particularly susceptible to acid rain
Rhizobium bacteria
Produce enzymes that convert atmospheric nitrogen into nitrates and other nitrogenous substances. Root nodules contain large numbers of nitrogen-fixing bacteria. They team up with the legume family
Human relevance of roots
Source of food, spices, dyes, drugs, insecticide
Soil formation
Air 25, water 25, mineral matter 45, organic matter 5
Soil divided into horizons
A, E, B, C
A horizon
Dark loam, with more organic material than lower layers
E horizon
Light loam
B horizon
Subsoil. More clay, lighter in color
C horizon
Parent material
Parent material
Rock that has not been broken down into smaller particles
Rock types
Igneous-volcanic. Sedimentary - deposited by glaciers, water, or wind. Metamorphic - changes in igneous or sedimentary rooks from heat and/or pressure
Soil contains many organisms and plant parts
Bacteria and fungi decompose. Roots and other living organisms produce carbon dioxide. Small animals alter soil. Humus
Humus
Partially decomposed organic matter, gives soil a dark color
Topography
Surface features. Steep areas: soil subject to erosion (wind water ice). Flat, poorly drained areas: pools and ponds may appear (slowing plant growth), development of soil arrested. Ideal topography permits drainage without erosion
Soil texture
Percentage of silt, sand, and clay
Sand
Small particles 2-.1 mm
Silt
Most microscopic .05-.002
Clay
Electron microscope <.002 mm
Micelles
Individual clay particles. Negatively charged. attract, exchange, or retain positively charged ions, such as K + or Mg ++
Best agricultural soils
Loams composed of 40 silt, 40 sand, and 20 clay. Coarse soils drain water too quickly. Clay soils allow little water to pass.
Soil structure
Arrangement or soil particles into aggregates. Productive agricultural soils are granular with pore spaces occupying between 40-60% of the total soil volume. Particle size more important than total volume.
Gravitational water
Drains out of pore spaces after a rain
Capillary water
Water held against the force of gravity in soil pores. Determined by structure and organic matter, by density and type of vegetation, and by the location of most underground water tables. Plants depend mostly on this type
Hygroscopic water
Physically bound to soil particles and unavailable to plants
Field capacity
Water remaining in soil after water drains away by gravity. Determined by texture, structure, and organic content of soil
Permanent wilting point
Insufficient water, and plant permanently wilts
Available water
Soil water between field capacity and the permanent wilting point
Soil pH
Affects nutrient availability. Usually best is 6.8. Alkalinity causes some minerals to become less available. Acidity inhibits growth of nitrogen fixing bacteria
shoot system
Branches and leaves
A woody twig
axis with attached leaves
node
area of stem where leaves are attached
alternate
single leaf at node
opposite
pairs of leaves at node
whorled
three or more leaves at node
internode
stem region between nodes
petiole
leaf attachment to twig. “stem” of leaf
axil
angle between petiole and stem
axillary bud
located in axil. becomes branches or flowers.
bud scales
protect buds
terminal bud
at twig tip. growth makes twig longer. number of groups of bud scale scars tells age of twig
stipules
leaf-like appendages at base of leaf
deciduous trees and shrubs
lose all leaves annually. after leaves fall, have dormant axillary buds with leaf scars below
bundle scars
mark vascular tissue within leaf scars
apical meristem at stem tip
contributes to increase in stem length. dormant before growing season begins. protected by bud scales and by leaf primordia
leaf primordia
tiny embryonic leaves that develop into mature leaves
three primary meristems of stems
protoderm, procambium, and ground meristem
protoderm
produces epidermis
procambium
produces primary xylem and phloem
ground meristem
produces pith and cortex, both composed of parenchyma cells (for storage)
leaf primordia and bud primordia
develop into mature leaves and buds
trace
strand of xylem and phloem. they branch off from stem and enter leaf or bud. each one leaves a gap filled with parenchyma in the cylinder of vascular tissue, forming leaf gap or bud gap
vascular cambium of stems
develops from a narrow band of cells between the primary xylem and phloem. cells produced by them become components of secondary xylem toward center and secondary phloem toward surface
cork cambium of stems
produced externally to the phloem. Highly “waterproof” to reduce water loss. Protects stem against injury. contains lenticels
Lenticels
Parenchyma cells in cork for exchange of gases.
Cotyledons
Seed leaves attached to embryonic stems (not new tissue in seed). May store food needed by young seedling.
Dicotyledons (dicots)
Flowering plants that develop from seeds having two cotyledons.
Monocotyledons (monocots)
Flowering plants that develop from seeds with a single cotyledon.
Annual
Plant that dies after going from seed to maturity within one growing season. Usually green, herbaceous plants. Most monocots are annuals, but many dicots are also annuals. Tissues largely primary.
Biennial
2 years from germination to flowering. (Doesn’t flower the first year)
Perennial
Plants with indefinite growth.
Vascular bundles of herbaceous dicot stems
arranged in a cylinder. vascular cambium arises between primary xylem and primary phloem. adds secondary xylem and secondary phloem
Wood
secondary xylem (over 90% of log is xylem)
Differences in wood if vascular cambium and cork cambium are active seasonally
during spring, relatively large vessel elements of secondary xylem produced (spring wood). during summer, fewer, smaller vessel elements in proportion to tracheids and fibers (summer wood). Conifers lack vessel elements and fibers; tracheids larger in spring than later in the season
Differences in wood if vascular cambium and cork cambium active year-round
ungrained, uniform wood produced (some tropical trees)
Annual ring
one year’s growth of xylem. Vascular cambium produces more secondary xylem than phloem. bulk of tree trunk consists of annual rings of wood. Indicates age of a tree. Indicates climate during tree’s lifetime.
Vascular Rays of Stems
Consist of parenchyma cells that function in lateral conduction of nutrients and water
Xylem ray of stem
Part of a ray withing xylem
Phloem ray of stem
Part of ray through phloem
Tyloses
Protursions of adjacent parenchyma cells into conducting cells of xylem. Prevent conduction of water. Resins, gums, and tannins accumulate and darken wood, forming heartwood
Heartwood
Older, darker wood in center
Sapwood
lighter, still-functioning xylem closest to cambium
Hardwood
Wood of dicot trees
Softwood
Wood of conifers. No fibers or vessel elements
Resin canals
Tubelike canals scattered throughout xylem and other tissues. Lined with specialized cells that secrete resin. Common in conifers and some tropical trees (olibanum frankincense, myrrh)
Bark
Tissues outside the vascular cambium, including the secondary phloem. Mature may consist of alternating layeers of chrushed phloem and cork
Laticifers
ducts found mostly in phloem that have latex-secreting cells (rubber, chicle chewing gum, morphine)
Monocot stems
have neither a vascular cambium nor a cork cambium. produce no secondary vascular tissues or cork. primary xylem and phloem in discrete vascular bundles scattered throughout the stem, oriented with xylem closer to interior of stem and phloem closer to exterior. Parenchyma (ground tissue) surrounds vascular bundles.
In a typical monocot vascular bundle
2-3 large vessels with several small vessels. first formed xylem cells stretch and collapse, leaving irregularly shaped air space. Phloem consists of sieve tubes and companion cells. Vascular bundle surrounded by sheath of sclerenchyma cells.
Rhizomes
Specialized stem. Horizontal stems that grow below ground and have long to short internodes (irises, some grasses, ferns).
Runners
Specialized stems. Horizontal stems that grow above ground and have long internodes (strawberry).
Stolons
Specialized stems. Produced beneath the surface of the ground and tending to grow in different directions. (potato formed at end of stolon as tuber).
Tubers
Swollen, fleshy, underground specialized stem that stores food. (potatoes - eyes of potato are nodes).
Bulbs
Specialized stem. Large buds surrounded by numerous fleshy leaves with a small stem at lower end. (Onions, lilies, hyacinths, tulips).
Corms
Resemble bulbs, but composed almost entirely of stem tissue with papery leaves. Store food. (crocus and gladiolus)
Cladophylls
Flattened, leaf-like stems. (greenbriars, some orchids, prickly pear cactus)
Primordia
Leaf origin in buds
At maturity, most leaves have
Stalk, flattened blade, network of veins, stipules
Stalk of Leaf
petiole. Leaves sessile if lacking petiole
Flattened blade
lamina
Network of veins
vascular bundles
Stipules
at base of petiole
Leaves of flowering plants
associated with leaf gaps and have axillary buds at base
Simple leaves
have a single blade
Compound leaves
blade divided into leaflets
Pinnately compound leaves
leaflets in pairs along rachis (petiole)
Bipinnately compound leaf
leaflets subdivided
Palmately compound leaves
All leaflets attached at same point at end of petiole
Photosynthesis
Capture and storage by green leaves of energy in sugar molecules that are constructed from water and carbon dioxide.
Stomata
Tiny pores most numerous on lower surfaces of leaves. Allows air circulation (CO2 in, O2 out during photosynthesis). Water vapor also escapes via stomata.
Guard cells
Control water loss by opening or closing pore of stomatal apparatus
Other functions of leaves
Wastes from metabolic processes accumulate in leaves and are disposed when leaves are shed. Play major role in movement of water absorbed by roots
Transpiration
Occurs when water evaporates from leaf surface
Guttation
Root pressure forces water out hydathodes at tips of leaf veins (esp. overnight)
Phyllotaxy
Arrangement of leaves on stem
Alternate
One leaf per node
Opposite
Two leaves per node
Whorled
Three or more leaves at a node
Venation
Arrangement of veins in a leaf or leaflet blade
Pinnate Venation
Main midvein included within enlarged midrib. Secondary veins branch from midvein.
Palmate venation
Several primary veins fan out from base of blade
Parallel venation
Monocots - primary veins parallel
Netted or reticulate venation
Dicots - Primary veins divergent in various ways
Dichotomous venation
veins fork evenly and progressively from base of blade
Three regions of leaf
Epidermis, mesophyll, veins (vascular bundles).
Epidermis of leaves
Single layer of cells covering the entire surface of the leaf. Devoid of chloroplasts. Coated cuticle (with cutin). Functions to protect tissues inside leaves. Waste materials may accumulate in epidermal cells. Different types of glands may also by present in the epidermis.
Lower epidermis
typically has a thinner layer of cutin and is perforated by numerous stomata
Stomata
Bordered by two guard cells.
Guard cell function
Gas exchange. Regulate water
Guard cell operation
Water pressure used to inflate or deflate. Deflate: stomata closed. Inflate: stomata open. Also contain chloroplasts (providing E to themselves)
Mesophyll of leaves
Site of most photosynthesis between epidermal layers.
Palisade Mesophyll
Compactly stacked, barrel shaped parenchyma cells, commonly in two rows. Contains most of the leaf’s chloroplasts.
Spongy mesophyll
Loosely arranged parenchyma cells with abundant air spaces.
Veins (vascular bundles of leaves)
Scattered throughout mesophyll, consisting of xylem and phloem tissues surrounded by bundle sheath of thicker-walled parenchyma.
Monocot Leaf Mesophyll
Usually not differentiated into palisade and spongy layers. often have bulliform cells on either side of the main central vein
Bulliform cells
partly collapse under dry conditions, causing leaf to fold or roll, reducing transpiration by reducing heat load and light reaching chlorophyll.
Shade leaves
Specialized leaves that receive less total light than sun leaves. Compared to sun leaves, they tend to be larger, thinner, have fewer will defined mesophyll layers and fewer chloroplasts, and have fewer hairs
Leaves of arid regions
Specialized; reduce loss of water by thick, leathery leaves; fewer (and/or sunken) stomata; succulent, water-retaining leaves or no leaves; dense, hairy coverings
Leaves of aquatic areas
Specialized. Less xylem and phloem; mesophyll not differentiated into palisade and spongy layers; large air spaces.
Tendrils
Modified leaves that curl around more rigid objects, helping the plant to climb or to support weak stems (garden peas)
Spines
Modified leaves that reduce leaf surface and water loss and protect from herbivory
Cacti leaves
Leaf tissue replaced with sclerenchyma. Photosynthesis occurs in stems
Thorns
Modified stems arising in the axils of leaves of woody plants
Prickles
Outgrowths from epidermis or cortex (like root hairs)
Storage leaves
Succulent leaves are modified for water storage - have parenchyma cells with large vacuoles; many desert plants store water in this way (aloe vera). Fleshy leaves store carbohydrates (onions, lily)
Flower-pot leaves
Leaves develop into urn-like pouches that become home of ant colonies. Ants carry in soil and add nitrogenous wastes that provide good growing medium for the plant’s own roots (Dischidia, an epiphyte of Australia).
Window leaves
Demonstrated in succulent desert plants of Africa. Leaves buried in ground except for exposed end. End has transparent, thick epidermis and transparent water storage cells underneath that allows light into leaf. Buried leaves keep plant from drying out
Reproductive leaves
Walking fern - New plants form at leaf tips.
Air plant - Tiny plantlets along leaf margins
Floral Leaves (bracts)
At bases of flowers or flower stalks.
Poinsettia - Flowers do not have petals, instead brightly colored bracts surround flowers.
Clary’s sage - Colorful bracts are at top of flowering stalks above flowers.
Insect-trapping Leaves (“Carnivorous”)
Grow in swampy areas and bogs. Nitrogen and other elements are deficient in soil. Specialized leaves trap and digest insects.
Pitcher plants
Insects trapped and digested inside cone-shaped leaves.
Sundews
Have round to oval leaves covered with glandular hairs that have a sticky fluid of digestive enzymes at tip
Venus flytraps
Only found in the Carolinas. Blade halves trap insects
Bladderworts
Submerged or floating in shallow water. Tiny bladders on leaves have trap doors that trap insects inside bladders in less than 1/100th of a second
Pigments of chloroplasts of mature leaves
Chlorophylls, carotenoids, and xanthophylls. In fall, Chlorophylls break down to reveal other colors
Chlorophyll pigment
Green
Carotenoid and Xanthophyll pigment
Yellow
Also present in the vacuole
Water soluble anthocyanins (red or blue based on pH) and betacyanins (red)
Tannins and proteins of many oak leaves
react to produce brown leaves
Deciduous plants
drop leaves seasonally
Abscission
Process by which leaves are shed. Occurs as a result of changes in zone near base of petiole
Protective layer of abscission zone
Cells coated and filled with suberin
Separation layer of abscission zone
Pectins in middle lamella of cells are broken down by enzymes
Two major classes of flowering plants
Magnoliopsida (dicot) - vascular bundles of stem in ring - and Liliopsida (monocots) - vascular bundles of stem scattered.
Embryonic primordium
Flower origin that develops into a bud
Peduncles
Specialized branches at the end of which flowers occur. may have branchlets of pedicels
Receptacle
Swollen end of peduncle or pedicel.
Whorls
Other parts of flower attached to the receptacle: sepals, petals, stamens, and pistil
Sepals
outermost whorl. Collectively referred to as calyx. Protects flower while in bud
Petals
Next whorl inside sepals. Collectively referred to as a corolla. Showy corollas attract pollinators. Inconspicuous or missing corollas in many trees, weeds, grasses, and wind-pollinated plants
Perianth
Calyx and corolla together
Stamens
Attached around base of pistil. Each one consists of filament with anther on top. Pollen grains developed in anthers
Pistil
Consists of stigma, style, and ovary. Ovary develops into fruit
Carpel
Ovule-bearing unit that is part of the pistil. may be fused together into compound ovary. Pistil can contain one to several of these, affecting number of seeds.
Superior ovary
Calyx and corolla attached to receptacle at base of ovary
Inferior ovary
receptacle grows up and around the ovary. Calyx and corolla appear attached at top of ovary
Ovules
Contained by ovary, they develop into seeds after fertilization
Inflorescence
groups of flowers
Fruit
Matured ovary and its accessory parts. Contains seeds. All of them develop from flower ovaries and accordingly are found exclusively in flowering plants.
Fruit regions
Pericarp
Exocarp - Skin
Mesocarp - tissue between exocarp and endocarp
Endocarp - inner boundary around seed(s)
Fleshy fruits
Mesocarp at least partly fleshy at maturity
Simple fleshy fruits
develop from flower with single pistil
Drupe
simple fleshy fruit with single seed enclosed by hard, stony endocarp (pit)
Berry
From compound ovary with more than one seed and with fleshy pericarp
True berry
with thin skin and relatively soft pericarp (tomatoes, grapes, peppers, blueberries, bananas)
Pepo berry
relatively thick rind (pumpkins, cucumbers)
Hesperidium berry
Leathery skin containing oils. (citrus - orange, lemon, lime)
Pome
Flesh comes from enlarged floral tube or receptacle that grows up around ovary. Endocarp papery or leathery. Core and a little of adjacent tissue is from ovary; remainder is from floral tube and receptacle. (Apples and pears).
Aggregate fruits
Derived from single flower with several to many pistils. Individual pistils mature as clustered unit on a single receptacle (raspberries, blackberries, strawberries).
Multiple fruits
Derived from several to many flowers in single inflorescence. Individual flowers mature as cluster. (mulberries, Osage orange, pineapples, figs)
Dry Fruits
Mesocarp dry at maturity
Dehiscent fruits
Split at maturity
Follicle
Splits along one site (larkspur, milkweed, peony)
Legume
Splits along two sides (legume family: peas, beans, lentils, peanuts)
Siliques and silicles
Split along two sides and seeds remain on now exposed central partition. (Mustard family: broccoli, cabbage)
Silique
More than three times longer than wide
Silicle
Less than three times longer than wide
Capsules
Consist of at least two carpels and split in a variety of ways. (Irises, poppies, violets, snapdragons)
Indehiscent fruits
do not split at maturity. single seed united with pericarp
Achene
Base of seed attached to pericarp (sunflower, buttercup, buckwheat)
Nut
Similar to achene, but larger, with harder and thicker pericarp and a cluster of bracts at base (acorns, hazelnuts, hickory nuts)
Grain (caryopsis)
Pericarp tightly united with seed. (Grasses: corn, wheat, rice, oats, barley)
Samara
Pericarp extends as wings for dispersal (maples, ashes, elms)
Schizocarp
Twin fruit that breaks into one-seeded segments called mericarps (parsley family: carrots, anise, dill)
Dispersal by wind
Fruits: samaras, plumes, or hairs on fruit
Seeds: small and lightweight or with wings
Dispersal by animals
Seeds pass through digestive tract; fruits and seeds adhere to fur or feathers; oils attract ants (Elaiosomes on bleeding hearts used as food by ants)
Water dispersal
Some fruits contain trapped air for floatation.
