BTNYFNLM52 Flashcards
The part of the axis of a plant that
bears the leaves and reproductive
structures.
___ and roots are alike in general
structures: xylem and phloem, pericycle,
endodermis, cortex and epidermis.
____ differ from roots in fundamental
structures known as the nodes and
internodes.
STEM
the first stem
of a seed plant. It is
short, cylindrical
structure bearing a
small mass of
meristematic tissue and
with tiny leaves at its
tip.
Epicotyl –
External Structure of the Stem
is the slightly enlarge portion of the stem where leaves and buds arise
Node –
External Structure of the Stem
is the region of a stem between two sucessive nodes
Internode –
External Structure of the Stem
tiny raised pores on the surface of matured dicot stem. They replaced the stomata for gaseous exchange.
Lenticels –
External Structure of the Stem
are marks left
on the stem such as:
Bundle scar
Bud scar
Fruit scar
Flower scar
Twig scar
Leaf scar
Scars –
External Structure of the Stem
are undeveloped shoot, largely meristematic tissue, generally protected by modified scale leaves
Buds –
Kinds of buds (as to location)
buds that are located at the tip of a stem or twig
terminal or apical buds –
Kinds of buds (as to location)
– buds that are located along the side of a stem
axillary or lateral buds
Kinds of buds (as to location)
– buds that are located beside or above the axillary or lateral buds
Accessory or supernumerary buds
Kinds of buds (as to location)
– buds that develop in places other than in the axils of leaves
adventituous buds
Kinds of buds (as to the presence or absence of protective covering)
– buds without scales
naked buds
Kinds of buds (as to the presence or absence of protective covering)
– buds with protective covering
protected or scaly buds
Kinds of buds (As to phyllotaxy [leaf arrangement])
– one bud at each node
Alternate
Kinds of buds (As to phyllotaxy [leaf arrangement])
– two buds at each node opposite each other
Opposite
Kinds of buds (As to phyllotaxy [leaf arrangement])
– three or more buds at each node
Whorled or verticillate
Kinds of buds (As to phyllotaxy [leaf arrangement])
– buds are in cluster around the node
Fascicled
Kinds of buds (as to content or structure)
– bud that produce leaves and stems
leaf bud or branch bud
Kinds of buds (as to content or structure)
– buds that develop into individual flowers
flower buds
Kinds of buds (as to content or structure)
– buds that produce both flowers and leaves
mixed buds
Kinds of stem ( as to location)
– stem
which grow above the soil surface
Aerial or epiterranean stem
Kinds of stem ( as to location)
stem which grow beneath the soil
Underground or subterranean
stem
Types of Aerial Stem
are woody, sharply pointed
branch stems to reduce the heating effect of the sun.
Thorns
Types of Aerial Stem
are small, unbranched, sharp outgrowths of leaf tissue in which the
parenchyma is replaced by sclerenchyma (e.g. cactus) for protection, to reduce the heating effect of the sun
Spines
Types of Aerial Stem
are small pointed outgrowths
from the epidermis or cortex of the
stem (e.g. Euphorbia, rose and
raspberry)
Prickles
Types of Aerial Stem
are flattened main stems that resemble leaves (e.g. butcher’s-broom,
greenbrier, and some orchids). Edible asparagus shoots left to grow produce many small fern-like ___
Cladophylls
Types of Aerial Stem
are paired scales, glands, or leaf-like structures at the base of the petiole formed from leaf or stem tissue.
Stipules
Types of Aerial Stem
are modified leaves at the base of flowers or flower stalks. Some are highlycolored and resemble petals (e.g. the red “petals” of poinsettia are bracts surrounding the small, yellow flowers).
Bracts
Types of Aerial Stem
can be exclusively leaf tissue (e.g. pea leaflets, nasturtium petioles, or cucumber leaves that twine and aid in supporting the shoots) or they can be
modified special shoots with thin, modified stems (e.g. morning glories, grapes, ampalaya)
are leaf tissue for support and climbing of the plants (E.g. bitter gourd, squash, cucumber).
Tendrils
Types of Aerial Stem
sometimes called runners, are thin, aboveground, horizontal stems of indeterminate growth and long internodes that grow out from a parent plant and produce young plants at their tips (e.g.
strawberry plant)
Stolons,
Types of Subterranean Stem
– is a swollen food
storing stem which grows in a characteristic horizontal direction bearing most of the features of a typical stem. E.g. Ginger, talahib, camia
are root-like stem that bears adventitious roots. It grows horizontally under the round and the lateral buds grow out to develop new ____
Rhizome (rootstock)
Types of Subterranean Stem
is a swollen, food storage organ which arises from the end of each branch of the underground stem. E.g. Potato
stored nutrients which become swollen and bulky portion of an underground stem. It consists of very short stems with a swollen apical structure, and it bears a number of nodes or eyes of an underground stem.
Tuber –
Types of Subterranean Stem
is the swollen base of an aerial shoot. It is a short, swollen structure covered
with dry leaves and having most of the
features of a typical stem. E.g. Gabi and gladiola
is a fleshy underground swollen stem that is similar to a bulb in terms of its shape and can stores its foods. They usually have a papery outer skin
Corm –
Types of Subterranean Stem
the stem of a bulb is in the
form of reduced, flattened disc. Food is stored in large, fleshy scale leaves arising
from the stem. E.g. Onion bulb,
lilies
consist of many thin layers of modified leaves having a miniature sprout in the center
Bulb –
Types of stems (as to direction of growth)
when they grow perpendicularly
from the ground
Erect,
Types of stems (as to direction of growth)
when they arise from the
ground obliquely
Ascending,
Types of stems (as to direction of growth)
when they are more or
less recline on the ground or near the
base
Decumbent,
Types of stems (as to direction of growth)
– when they lie flat on the ground
Prostrate
Types of stems (as to direction of growth)
– when they are very close to the ground and develop roots at its base
Creeping
Types of stems (as to direction of growth)
–
when growing over other
plants or objects as support
a. tendril climber
b. twinner
c. root climber
d. hooks
e. scramblers
Climbing or scandent stems
is a common method of reproduction in which a small piece of a woody stem has been cut off from a mother plant.
Stem cutting
is a method of combining the scion and the rootstock.
Grafting and budding
Kinds of stems (as to texture)
When they contain very little
woody tissue, live for only a
year or less, and die after
flowering and producing
seeds
Soft and green
Little growth in diameter
Tissues chiefly primary
Chiefly annual
Covered by an epidermis
Buds mostly naked
Herbaceous Stem
Kinds of stem (as to texture)
When they have welldeveloped
woody tissue,
like shrubs and trees
Tough and not green
Considerable growth of
diameter
Tissues chiefly secondary
Chiefly perennial
Covered by corky bark
Buds chiefly covered with
scales
Woody stem
Types of stem
The vascular tissue exists as
scattered bundles of xylem
and phloem. The bundles are
more numerous at the
periphery than at the middle
of the stem. There is no
definite arrangement of
vascular bundles.
Herbaceous
Monocotyledonous Stem
Types of stem
The vascular tissues are
arranged in discrete bundles,
but the bundles themselves
arranged in an orderly ring
and not scattered.
Herbaceous Dicotyledonous
Types of Stem
The conducting tissues
of mature woody stems
are in the form of
concentric cylinder in
which the great
development of
secondary xylem results
in the characteristics
woody condition. These
stems usually have much
less pith than
herbaceous
dicotyledonous stems
Woody Dicotyledonous Stem
Structure found in the Wood
– are concentric
layers of the xylem formed
by one year’s growth activity
of the cambium.
Composition of the annual
ring:
1. – is the inner
band of each ring that is
made up big cells formed by
the cambium in the spring
2. – outer band
of each ring which is smaller
and thick walled cells
formed in the summer
Annual rings
springwood
summerwood
Structure found in the Wood
____ lies outside the
heartwood. _____ is
much valuable because it is
used in constructing
buildings.
B. Heartwood and Sapwood
Forms of Trees
trees with cylindrical, unbranched and
usually bears at its summit on one set of leaves.
ex: Palm Trees
Columnar
Forms of Trees
consists of one principal vertical stem –the trunk which tapers from base to summit.
From it, smaller horizontal branches radiate
ex: Pine Trees
Excurrent –
Forms of Trees
– consists of a vertical
main stem or trunk rises for some distance above the ground and then divides into several branches.
ex: acacia
Deliquescent
