Download The stem - The Virtual Plant

The origin of the secondary plant
body and the periderm
SPECIMENS
TECHNIQUES :3, 7, 8, 9
*Bidens pilosa TS stem.
Mature Helianthus stem
*Chrysanthemum TS stem.
*Helianthus TS root
DEMONSTRATIONS:.
*Bougainvillaea TS stem
.
Beta vulgaris TS stem
.
*Prunus TS woody stem
.
Beta TS root
.
Quercus - two and four-year-old stem, TS
Chrysanthemum stem
TS vascular bundle
metaxylem
protoxylem
Chrysanthemum stem
starch sheath
primary phloem fibres
primary phloem
sieve element
companion cell
secondary phloem
vascular cambium
secondary xylem
metaxylem vessel
metaxylem tracheids
Helianthus TS young stem. end of primary growth
epidermis
outer cortex collenchymatous
primary phloem fibers
primary phloem
fascicular cambium
metaxylem
protoxylem
interfascicular cambium
Helianthus: secondary growth
secondary growth is limited
to a narrow band within the
vascular bundle
Sugar beet stem
epidermis
outer cortex: collenchyma
inner cortex: parenchyma
starch sheath
Secondary xylem
phloem
metaxylem
The root
.
cambium
protoxylem
included phloem
px
mx
cambium
In the root, these
included bundles
form new
secondary
vascular tissue,
and grow
anomalously
ANOMALOUS GROWTH
Included bundle
phloem
metaxylem
protoxylem
Ground parenchyma
Bougainvillaea stem
vascular cambium, producing
secondary phloem (exarch) and
secondary xylem (endarch)
Bougainvillaea shows anomalous
secondary growth. Note primary
vascular bundles embedded within
the stele.
Bougainvillaea TS stem
primary vascular bundle
secondary xylem
Sugar beet (Beta) root
multiple cambia, secondary
vascular bundles and embedded
primary vascular bundles. This is
an anomalous structure
secondary
vascular bundle
Oak (Quercus) stem
periderm
secondary phloem
fibers and sclerieds
secondary phloem
cambium
primary ray
secondary xylem
Oak stem, Periderm
and lenticels
secondary phloem fibres
lenticel
The cambium, Quercus stem
primary ray
companion cell
secondary phloem
vascular cambium
secondary xylem
Sunflower (Helianthus) root
secondary xylem
formation is not
continuous
primary xylem