Indeterminate growth
•	Unlike animals most plants 
grow throughout their life
•	annuals
•	life cycle within 1 year
•	germination  flowering  seed production
•	perennials
•	live many years
•	does not die of old age, 
only disease or trauma
Meristem 
•	Regions of growth
•	stem cells: perpetually embryonic tissue
•	regenerate new cells
•	apical shoot meristem
•	growth in length
•	primary growth
•	apical root meristem
•	growth in length
•	primary growth
•	lateral meristem
•	growth in girth
•	secondary growth
Apical meristems
Root structure & growth
Shoot growth
•	Apical bud & primary growth of shoot
•	region of stem growth
•	axillary buds 
•	“waiting in the wings”
Shoot growth
•	Since woody plants grow from year to year, they evolved a different growth system than herbaceous plants which die back each year
Growth in woody plants
•	Woody plants grow in height from tip
•	primary growth
•	apical meristem
•	Woody plants grow in diameter from sides
•	secondary growth
•	lateral meristems
•	vascular cambium
•	makes 2° phloem & 2° xylem
•	cork cambium
•	makes bark
Secondary growth
•	Secondary growth
•	growth in diameter
•	thickens & strengthens older part of tree
•	cork cambium makes bark
•	growing ring around tree
•	vascular cambium makes xylem & phloem 
•	growing ring around tree
Vascular cambium
•	Phloem produced to the outside
•	Xylem produced to the inside
Woody stem
Tree trunk anatomy
Where will the carving be in 50 years?