figure 35.18 primary and secondary growth of a stem (layer 1)
DESCRIPTION
(a) Primary and secondary growth in a two-year-old stem. 1. Pith. Primary xylem. Epidermis. Vascular cambium. Cortex. Primary phloem. Figure 35.18 Primary and secondary growth of a stem (layer 1). (a) Primary and secondary growth in a two-year-old stem. 3. 1. 2. 4. Pith. - PowerPoint PPT PresentationTRANSCRIPT
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 35.18 Primary and secondary growth of a stem (layer 1)
(a) Primary and secondary growth in a two-year-old stem
Pith
Primary xylemVascular cambium
Primary phloem
Epidermis
Cortex
1
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 35.18 Primary and secondary growth of a stem (layer 2)
Vascular cambium
4 First cork cambium
Pith
Primary xylemVascular cambium
Primary phloem
Epidermis
Cortex
2
1
Growth
Primary xylem
Secondary xylemPrimary phloem
Cork
Phloem ray3 Xylem
ray
Secondary phloem
(a) Primary and secondary growth in a two-year-old stem
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 35.18 Primary and secondary growth of a stem (layer 3)
Vascular cambiumPith
Primary xylemSecondary xylem
Vascular cambium
Secondary phloem
Primary phloem
Periderm(mainly cork cambiaand cork)
PithPrimary xylem
Vascular cambium
Primary phloemCortex
Epidermis
Vascular cambium
4 First cork cambium
Secondary xylem(two years ofproduction)
Pith
Primary xylemVascular cambium
Primary xylem
Epidermis
Cortex
2
1
6
Growth
Primary xylem
Secondary xylem
Secondary phloem
Primary phloem
Cork
Phloem ray3 Xylem
ray
Growth
9 Bark
8 Layers of periderm
7 Cork
5 Most recentcork cambium
(a) Primary and secondary growth in a two-year-old stem
Secondary phloem