Day 9, botany, leaves

-photosynthesis

-transpiration

-at the node

-just below the axillary/lateral bud

-blade

-petiole

-stipules

-veins

-venation

-type of leaf

green and leafy

-leaf stalk

-not always present

-paired (2 at a node)

-just below the leaf

-often fall off or not seen

-net veins : Dicots

- parallel veins : Monocot

-pinnate veins and palmate veins

• -mid rib and side veins
• * feather or ladder like

many veins radiating from center

ex) maple leaf

simple leaf and compound leaf

-blade is all in one piece

(look for auxillary bud)

-blade divided into segments

-has leaflets

branch then branches off

-looks like a palm

-Environmental conditions

-tendrils

-spines

-scales

-bracts

-insectivorous

-dry and arid

-has sunken stomates

ex) cacti, succulents

-wet and aquatic

-stomates on top

ex) underwater and floating plants

-middle conditions

-used for attachments

-some vines have it

ex) peas and grapes

-protection

-modification of leaves to prevent water loss

ex) barberry or cacti

• -fleshy leaves (bulbs)
• *used for storage
• ex) onions

-protection

-just below the flowers

-green or colored

ex) poinetta

-catch bugs with leaves

-used to get extra nitrogen

-upper and lower epidermis

-one layer thick

-parenchyma tissue (lack chloroplasts

-cuticle (waxy covering)

-can have hairs or trichomes

-lower epidermis contained guard cells and stomates

-middle of leaf

-chlorenchyma

2 levels: palisade and spongy layer

-towards the top

-are a few layers

-vertical cells

-tightly packed

-***they trap light

-toward bottom

-has air spaces

-gas exchange with stomates

-loose

-vascular bundle in the leaf

• *xylem towards the top of leaf
• *Phloem towards the bottom of leaf
• *bundle sheath surrounds the leaf