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cross section of a trunk click to hear : 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.
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See cross section of a trunk in : french | spanish
heartwood pith bark phloem cambium sapwood annual ring wood ray

heartwood click to hear : heartwood

Hard dark-colored wood layer made of dead sapwood; it encircles the pith and supports the trunk and branches.

pith click to hear : pith

Central part of the trunk, composed of soft tissue that contains nutrients essential for sapling growth.

bark click to hear : bark

Tree’s external protective layer; its texture and color vary depending on the species.

phloem click to hear : 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 click to hear : cambium

Growth tissue that simultaneously produces the external phloem and the internal sapwood, thereby enabling the tree to increase in diameter.

sapwood click to hear : 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 click to hear : 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 click to hear : wood ray

Conduit connecting the pith to the core and circulating nutrients horizontally within the trunk.