Plant Leaves Flashcards
What is the first embryonic leaves?
Cotyledon
What are the two things leaves are involved in
Photosynthesis and gas exchange
Leaves should be what?:
To maximize absorption of light and gases
Flat and thin
Leaves should be what?:
most of their tissues should be what to carry out photosynthesis
alive and differentiated into chlorenchyma
Stems should be what?:
To maximize support and conductions with minimum expenditure of construction
Cylindrical
Stems should be what?:
Much of the stem and all of its tracheary elements and most fibers must what?
Die ~ functionally dead
External features of SIMPLE leaf:
tip
Apex
External features of SIMPLE leaf:
Point attachment
Base
External features of SIMPLE leaf:
Side
Margin
External features of SIMPLE leaf:
Main vein
Midrib
External features of SIMPLE leaf:
Strand of vascular tissues
Veins
External features of SIMPLE leaf:
Expanded leaf blade
Lamina:
- Adaxial: Ventral surface
- Abaxial: Dorsal surface
External features of SIMPLE leaf:
Leaf stalk
Petiole
External features of SIMPLE leaf:
Leaf appendages at petiole
Stipule
External features of SIMPLE leaf:
Angle between the leaf and stem
Axil
External features of SIMPLE leaf:
Veins originate from midrib at SEPARATE points
Pinnately lobed
External features of SIMPLE leaf:
Veins originate from the midrib at SINGLE point
Palmately lobed
External features of COMPOUND leaf:
One expanded part of compound leaf
Leaflet
External features of COMPOUND leaf:
stalk of individual leaflet
Petiolule
External features of COMPOUND leaf:
Distal to petiole - bears leaflets
Rachis
External features of COMPOUND leaf:
Stipule-like outgrowths at base of leaflet
Stipel
External features of COMPOUND leaf:
Leaflets are attached to rachis
Pinnately compound
External features of COMPOUND leaf:
Leaflets are attached to a SINGLE point in the petiole
Palmately compound
External features of Leaf - Venation:
Common in angiosperms, netlike
Netted or reticulate venation
External features of Leaf - Venation:
common in monocots, parallel
Parallel venation
External features of Leaf - Venation:
First set of veins point towards apex
Anadromous
External features of Leaf - Venation:
First set of veins point towards leaf base
Catadromous
External features of leaf - Leaf shape:
What does leaf shape hel;p the plant in
- aesthetics
- gas exchange
- Water retention
- light capture
External features of a leaf - Leaf Apex:
What are its benefits
Affect water drainage to prevent fungal infections and maximize light capture
External features of a leaf - Leaf Base:
What are its benefits
Enhance leaf stability and support while facilitating efficient nutrient and water transport from stem to blade
External features of a leaf - Leaf Margin:
What are its benefits
Light capture
Water runoff
Defense
External features of a leaf - petiole, base, stipule:
With petiole
Petiolate
External features of a leaf - petiole, base, stipule:
Without petiole
Sessile
External features of a leaf - petiole, base, stipule:
With stipule
Stipulate
External features of a leaf - petiole, base, stipule:
Without stipule
Exstipulate
External features of a leaf - petiole, base, stipule:
Leaf base wraps around stem; lacks petiole (sessile)
Sheathing of Leaf base
External features of a leaf - phyllotaxy:
Name four most common leaf phyllotaxy
Opposite, alternate, whorled, spiral
Internal features of a leaf - Epidermis:
Single layer of cells in adaxial and abaxial part of leaf and contains cuticle
Epidermal cells
Internal features of a leaf - Epidermis:
Forms the stomata and allows for gas exchange found in abaxial side of leaf
Guard cells
Internal features of a leaf - Epidermis:
Can be glandular or non-glandular and found in adaxial side of leaf for protection
Trichomes
Internal features of a leaf - Mesophyll:
Consists of one or more layers of elongated chlorenchyma specialized in light absorption and tightly packed
Palisade layer/mesophyll
Internal features of a leaf - Mesophyll:
Consists of several layer of irregularly-shaped parenchyma; normally surrounds vascular bundles and forms labyrinth of spaces
Spongy layer/mesophyll
Internal features of a leaf - Vascular Bundles:
Composed of collenchyma cells for support and protection of vascular bundle tissues
Bundle sheath
Internal features of a leaf - Vascular Bundles:
Mass of fibers above, below, or both in larger veins for additional support
Bundle sheath extension
Internal features of a leaf - Vascular Bundles:
Composed of tracheary elements, normally located in the upper portion and conducts water
Primary xylem
Internal features of a leaf - Vascular Bundles:
Composted of sieve members, located in the lower portion and conducts sugar
Primary phloem
Leaf Modification:
compact assemblage of overlapping and spirally arranged leaf sheathes
Support: Psuedostem
Leaf Modification:
Slender coiling structure derived from branch, leaf, or inflorescence and used in climbing and support
Support: Leaf tendril
Leaf Modification:
Leaf tip modified into tendril for support and senses solid objects around then
Support: Apex tendril
Leaf Modification:
thick and fleshy that favor water conservation
Storage: Thickened leaves or succulents
Leaf Modification:
large epiphatic ferns trap organic debris that is decomposed, becomes canopy soil and store water externally
Storage: Pocket or nest leaves
Leaf Modification:
Comes in stipular, petiular and leaflet form to protect
Protection: Spines
Leaf Modification:
Ability to puncture skin with needle-like apical cell with stiffened walls. Toxins secreted when tip is broken
Protection: Stinging trichome
Leaf Modification:
Red conical structure that lengthens and unrolls and protects new leaf from UV rays
Protection: United stipules
Leaf Modification:
Swelling of petiole that permit leaf movement
Protection: Pulvinus
Leaf Modification:
Modified or specialized leaf in the inflorence below partial peduncles, pedicels, or flowers
Attraction: Colored bracts
Leaf Modification:
Enhance light capture
Photosynthesis: Blade-like stipule, petiole, phyllode
Leaf Modification:
leaf margins produce tiny plantlets that fall off and grow independently
Reproduction: Marginal Notches
Leaf Modification:
bulbous stacks that contain air-filled tissues to keep plant afloat
Buoyancy: Bulbous petiole
Leaf Modification:
laminate is tubilar rather than flat and secretes a digestive fluid. the epidermis must be absorptive rather than impermeable
Traps: Pitcher-like apex
Leaf Modification:
Trap insects like flies with hinged leaves
Trap: Hinged trap leaves
Leaf Modification:
Secrete digestive fluid through large trichomes that wrap around suspect
Trap: Glandular trichome