MODULE 4: STEM Flashcards
Crucial part of plant physiology and become the erect, aerial SHOOT SYSTEM which contains the branches & leaves.
STEM
It is the axis of the shoot system which provides mechanical support to the plant; It is the site where leaves and reproductive shoots get attached; It also conducts water and minerals from roots to the leaves and solutes from leaves to storage and use sites.
STEM
Exposes the leaves for photosynthesis and positions the reproductive shoots for optimal access to pollinators and dispersal agents; Storage of food and/or water
STEM
2 TYPES OF STEM:
- HERBACEOUS STEM
- WOODY STEM
Thin, soft and green in color except those that grow underground.
HERBACEOUS STEMS
Taller, thicker, and harder than herbaceous stems.
WOODY STEMS
External Parts of the Stem:
- NODE
- INTERNODE
- BUD
- Axillary bud
- Terminal bud - BUD SCALES
- TERMINAL BUD SCALE SCARS
- STIPULE SCARS
- LEAF SCARS
- BUNDLE SCARS
- LENTICLE
EXTERNAL PARTS:
- Area of the stem where a leaf or leaves are attached.
NODE
EXTERNAL PARTS
- Stem region between nodes
INTERNODE
EXTERNAL PARTS
- Located at the angle (axil) between a petiole & stemp
BUD
2 TYPES OF BUDS:
- AXILLARY BUD
- TERMINAL BUD
TYPES OF BUDS
Bud at the axillary; forms into separate branches
AXILLARY BUD
TYPES OF BUDS
Present at the end of the twig (not always); does not form into branches
TERMINAL BUD
EXTERNAL PARTS
Protects buds; falls off when bud tissue starts to grow.
BUD SCALES
EXTERNAL PARTS
Marks leaves on the stem from the previous years which serve as external measure of annual growth.
TERMINAL BUD SCALE SCARS
EXTERNAL PARTS
Left after buds expand; maybe fine line encircling the twig (or inconspicuous)
STIPULE SCARS
EXTERNAL PARTS
Left after leaves fall
LEAF SCARS
EXTERNAL PARTS
Mark the location of water conducting & food conducting tissue
BUNDLE SCARS
EXTERNAL PARTS
Pores that allow for gas exchange
LENTICEL
TERMINOLOGY
- SHOOT
- TWIG
- BRANCH
- TRUNK
TERMINOLOGY
A young stem (1 year old or less) with leaves
SHOOT
TERMINOLOGY
A young stem (1 year old or less) that is in the dormant winter stage (no leaves)
TWIG
TERMINOLOGY
A stem that is more than 1 year old typically with lateral stems radiating from it
BRANCH
TERMINOLOGY
A woody plant’s main stem
TRUNK
The apical meristem is dormant before the growing season begins.
LEAF PRIMORDIA
Protected by bud scales of the bud in which it is located and to certain extent by the tiny embryonic leaves that will develop into mature leaves after the bud scales drop off and growth begins.
LEAF PRIMORDIA
MERISTEMATIC TISSUES
Coated & protected by a cuticle; from the protoderm
PROTODERM = EPIDERMIS
MERISTEMATIC TISSUES
- PROTODERM = EPIDERMIS
- PROCAMBIUM = PRIMARY XYLEM AND PHLOEM
- GROUND MERISTEMS
- Pith
- Cortex
MERISTEMATIC TISSUES
PROCAMBIUM = PRIMARY XYLEM AND PHLOEM
MERISTEMATIC TISSUES
Parenchyma tissue in the center of the stem
PITH
MERISTEMATIC TISSUES
From the ground meristem
CORTEX
VASCULAR CAMBIUM
- SECONDARY XYLEM
- SECONDARY PHLOEM