Structure
of a tree
The tree is
composed of an underground part, the roots, and two aboveground parts, the
trunk and the crown.
bole
Part of the
tree trunk extending between the stump and the first lower limbs; it has no
offshoots.
limb
Offshoot
growing directly out of a tree trunk, subsequently dividing into branches and
twigs.
twig
The most
slender offshoot of a tree branch.
crown
Part of the
tree above the trunk, including the branches and the foliage.
radicle
The most
slender offshoot of a tree root.
shallow
root
Root, often
having many offshoots, growing somewhat horizontally into the rich moist
topsoil.
taproot
First root
growing out of the seed that grows vertically into the soil; it usually has few
offshoots, its main function being to anchor the tree in the ground.
branch
Offshoot of
one of the tree’s limbs.
top
Apex of the
tree’s crown.
branches
The
aggregate of larger and smaller branches that provide support for the tree’s
leaves, flowers and fruit.
foliage
The
aggregate of the leaves on a tree; it is especially adapted to capture light
and perform photosynthesis.
root-hair
zone
Part of the
radicle covered in small absorbent hairs that ensure the tree is supplied with
mineral salts and water.
Cross
section of a trunk
Moving from
the center to the periphery there are six parts: the pith, the heartwood, the
sapwood, the cambium, the phloem and the bark.
heartwood
Hard
dark-colored wood layer made of dead sapwood; it encircles the pith and
supports the trunk and branches.
pith
Central
part of the trunk, composed of soft tissue that contains nutrients essential
for sapling growth.
bark
Tree’s
external protective layer; its texture and color vary depending on the species.
phloem
Tissue
located immediately below the bark, whose main function is to transport sap
transformed by photosynthesis from the leaves throughout the rest of the tree.
cambium
Growth
tissue that simultaneously produces the external phloem and the internal
sapwood, thereby enabling the tree to increase in diameter.
sapwood
Relatively
new layer of wood that is generally pale in color; it transports raw sap,
composed of water and nutrient minerals, from the roots to the leaves.
annual ring
Each of the
concentric circles representing the layer of wood produced in one year; the age
of the tree can be determined by the number of rings.
wood ray
Conduit
connecting the pith to the core and circulating nutrients horizontally within
the trunk.
