Stems Flashcards
Main Functions of Stems
Support
– leaves and reproductive structures
Conduct
– water, dissolved minerals, carbohydrates
Produce new living tissues
– at apical meristems
– at lateral meristems (secondary growth)
Contains the apical meristem.
Apical bud:
Located at the conjecture between the peitole, or the leaf and the stem.\
Produces new
leaves or stems.
Axillary bud:
Area where leaves arise.
Nodes
Portion between the nodes.
Internodes
Also present in tropical species, and in mangroves
one of many raised pores in the stem of a woody plant that allows gas exchange between the atmosphere and the internal tissues.
Lenticels
More obvious in temperament species because they have distinct seasons.
scars are the scars remaining after the bud scales fall off.
scar remaining after the leaf falls off.
(two items)
Leaf Scar and Bud Scar.
Tropic seasons don’t have too much
distinction in terms of temperature changes so the scarring isn’t obvious.
true
Papaya tree: Has obvious leaf scars that are considered characteristics of the tree, but is not a woody dicot nor a tree
true
leaf primordia
groups of cells that will form into new leaves. These new leaves form near the top of the shoot and resemble knobby outgrowths or inverted cones.
giving rise to the epidermis.
Protoderm
giving rise to vascular tissues: the water-conducting Xylem and the food-condcuting Phloem (FOR STEMS).
Procambium
giving rise to ground tissues: Pith (center) and the Cortex (between the epidermis and phloem).
Ground meristem
Defined differences between stem tissues having defined functions.
Area of cell maturation
No cuticle
Root cap
Root hairs
Pericycle
Endodermis
Branches form internally from
the pericycle
Photosynthetic
Pith
Cuticle No cap Trichomes
No pericycle Endodermis rare
Branches form externally from lateral buds
Note: Some exceptions to these general differences exist.
Roots and stems difference with nodes
herbacious dicot
ROOTS
No nodes or internodes
STEMS
Nodes and internodes
Roots and stems difference with leaves and buds
herbacious dicot
ROOTS
No leaves or buds
STEMS
Leaves and buds
Roots and stems difference with pith
herbacious dicot
ROOTS
No pith
STEMS
pith
Roots and stems difference with cuticle
herbacious dicot
ROOTS
No cuticle
STEMS
cuticle
Roots and stems difference with pericycle
herbacious dicot
ROOTS
pericycle
STEMS
no pericycle
Roots and stems difference with endodermis
herbacious dicot
ROOTS
endodermis
STEMS
endodermis rare
Vascular bundles in monocots and dicots
Dicots: Larger vascular bundles, more organized. circular
Monocots: Smaller vascular bundles, scattered.
Ground tissue in monocots and dicots
Dicot: Central pith and cortex.
Monocot: Cannot distinguish cortex from the pith.
epidermis is covered by water conserving ___
cuticle
no vascular cambium in monocot stems
true
herbacious dicot does not have an active vascular cambium
true