Morphoanatomy of Stem Flashcards
an axis
stem
stem plus any leaves, flowers, or
buds that may be present
shoot
provide internal transport
stem
support leaves and reproductive
structures
stem
produce new living tissue
stem
points at which leaves, aerial roots, and flowers are attached
nodes
segments between nodes
internodes
the area between the base of a leaf
and the stem – where it can give rise to a branch or a flower
axillary bud
contains the apical meristem
terminal bud
tiny raised pores for gaseous exchange
lenticels
where the leaf stalks grew from the
stem
leaf scars
appear as tiny raised dots in the leaf scars
bundle scars
ring of small narrow scars left by falling away of the bud scales and
forming a complete thin circle
around a twig
bud scars
circular scars left by the falling away
of branch twigs
twig scars
are green throughout without
deposition of lignin that would make them woody
herbaceous stems
The apical meristem
produces ___
and ___
leaf primordia ; bud primordia
will form leaves
leaf primordia
will form shoots
bud primordia
The shoot meristem has ___ producing the epidermis and the layers of cells beneath it
tunica
produces the cortex, pith and vascular tissues
corpus
zone in apical shoot meristem where cell division occurs
central zone
zone where leaves, shoots and new
meristems form
peripheral zone
zone where stem growth occurs
rib zone
stomata in herbaceous plant becomes ___ when matured
lenticels
come from vascular bundle in dicot stem
bundle scars
The influence of the apical bud on overall plant growth
apical dominance
diminishes the growth of axillary buds that form along the sides of branches and stems
apical dominance
when apical dominance occurs, growth of ___ ___ is suppressed
lateral buds
adds leaves and lengthens stems and roots in the younger regions of
a plant
primary growth
thickens stems and roots in older regions where primary growth has stopped
secondary growth
produces replacement cells in the plant body so that newly formed cells in root and shoot tips remain connected
secondary growth
cut in a plane that does not pass through the center of the stem but instead passes at a right angle to
a radius
tangential section
cut in a plane that passes through the center along a radius of the stem
radial section
Both tangential and radial
sections are
longitudinal sections
usually arises from parenchyma cells in the outer cortex, produces periderm
cork cambium
functional replacement for the epidermis
periderm
areas of the cork in which the cork cells are loosely arranged, permitting gas exchange through the periderm
lenticels
wood of flowering plants
hardwood
wood of conifers
softwood
wood of conifers lack fibers and vessel elements
softwood
only conducting cells for conifer woods
tracheids
science of analyzing tree ring growth patterns
dendrochronology
tool that can be drilled into the center of a tree
increment borer
the older layers of secondary xylem no longer transport water and minerals
heartwood
they are closer to the center of a stem or root
heartwood
The newest, outer layers of secondary xylem still transport xylem sap
sapwood
run almost parallel to the ground, or just below the surface
runners
give rise to new plants at the nodes
runners
flattened leaf-like appearance that performs photosynthesis
cladophylls
leafless, spirally coiled structure found in climbers
stem tendrils
sharp outgrowths that protect the plant
thorns
fleshy and horizontal stem found below in soil
rhizome
Small nodes and internodes are
found which are covered by scaly leaves.
rhizomes
Vertical shoots may arise from the buds
rhizome
stores food for renewing the growth of shoots after periods of
stress
rhizome
store starch
tuber
arise as swollen ends of stolons, and contain many adventitious or
unusual buds
tuber
large buds surrounded by numerous fleshy or papery leaves with a small stem at the lower end for food and water storage during dormancy
bulb
composed almost entirely of stem
tissue, except for the few papery, scale-like leaves sparsely covering the outside
corms
