Branches flat on ground,
Branches spread in all directions,
Some branches are partially vertical,
Types of Aerial Stem
- Stem is reduced to small disc.
- Nodes and internodes are not distinguishable.
- They are modified as per the need of plants,
- Reduced green discoid stem is present above
the base of root, with leaves crowded together
on it (radical leaves), e.g., carrot, turnip, etc.
- Reduced discoid stem may be green and
flattened to float on water surface, e.g., Wolffia,
- Common type of aerial stem. Sufficiently strong to remain erect or upright
without any external support, e.g., maize, mango.
Erect stems with swollen nodes or jointed stems, e.g., bamboo.
It is unbranched erect stem.
Branched erect stems may be either excurrent or deliquescent.
Stem clings to the support
by adventitious roots, e.g.,
Green thread like sensitive structures called
tendrils that coil around support and help weak
shoots to climb up, e.g., Passiflora, Antigonon.
Stems are able to rise up a support by clinging
to it with the help of curved thorns, e.g.,
Bougainvillea, leaflet hooks, e.g., Doxantha, etc.
or climbers, e.g.,
- Such stems are thin, soft and cannot stand erect, therefore, require a
- These stems are broadly of two types.
Weak stem, require support of ground for spreading and proper exposure of leaves and reproductive organs.
- Long, slender, flexible and sensitive stem. Coils around
an upright support like a rope, e.g., Lablab, Ipomoea.
- Weak and flexible stem that are unable to coil around an upright
support by itself, but requires certain clasping structures.
- The shoots trail or spread horizontally
along the ground without rooting at
intervals, e.g., Convolvulus, Euphorbia.
- The shoots spread along the ground and root at intervals. They also help in vegetative propagation.
- One internode long, small runners
usually found in rosette plants at the
ground or water level. E.g., Eichhornia.
- Horizontal or arched runner which can
cross over small obstacles.
- Each stolen has one or more nodes possessing
scale leaves and axillary buds.
- It possesses comparatively longer
internodes. E.g., Fragaria.
- Develops at the base of erect shoot
called crown and grows horizontally on
the surface of soil.
- Each runner has one or more nodes which
bear scale leaves and axillary buds.
E.g., Cynodon dactylon
Fig.:Runner of grass