Forest Trees of Texas
How To Know Them
Eighth Edition
Ninth Printing
October, 1990
TEXAS FOREST SERVICE
A PART OF
THE TEXAS A&M UNIVERSITY SYSTEM
COLLEGE STATION, TEXAS
BULLETIN 20 APRIL, 1963
[CROWN] TRUNK [HEARTWOOD] (INACTIVE) GIVES STRENGTH [SAPWOOD] CARRIES SAP FROM ROOT TO LEAVES [CAMBIUM] (MICROSCOPIC) BUILDS THE CELLS INNER [BARK] CARRIES PREPARED FOOD FROM LEAVES TO CAMBIUM LAYER OUTER BARK PROTECTS TREE FROM INJURIES ROOTS SURFACE ROOTS TAPROOT
Tree increases each year in height and spread of branches by adding on new growth of twigs
Air supplies carbon the principal food of the tree taken in on under surface of leaves.
Leaves prepare the food obtained from air and soil and give off moisture by transpiration. Light and heat are necessary for the chemical changes
The breathing pores of the entire tree,—on leaves, twigs, branches, trunk and roots take in oxygen. Flooding, poisonous gases, or smoke may kill a tree
Root tips or root hairs take up water containing small quantity of minerals in solution
The buds, root tips, and [cambium] layer are the growing parts of the tree. Water containing a small quantity of minerals in solution is absorbed by the roots, carried up through the [sapwood] to the leaves and there combined with carbon from the air to make food. This food is carried by the inner [bark] to all growing parts of the tree, even down to the root tips