Sap is a fluid transported in xylem cells (tracheids or vessel elements) or phloem sieve tube elements of a plant. The xylem cells transport water and nutrients throughout the plant.
Xylem sap consists primarily of water, with hormones, mineral elements and other nutrients dissolved in it. Transport of sap in xylem is characterized by movement from the roots toward the leaves. Over the past century, there has been some controversy regarding the mechanism of xylem sap transport; today, most plant scientists agree that the cohesion-tension theory best explains this process.
Phloem sap consists primarily of water, with sugars, hormones, and mineral elements dissolved in it. It flows from where carbohydrates are produced or stored to where they are used. The pressure flow hypothesis proposes a mechanism for phloem sap transport.
Maple syrup is made from reduced sugar maple xylem sap. It is often from the Sugar Maple, or Acer saccharum. In some countries (e.g., Russia, Latvia, Estonia or Finland) it is common to collect the early spring sap of birch trees (so called "birch juice") for human consumption; the sap can be used fresh or fermented and contains xylitol.
Famous quotes containing the words plant and/or sap:
“When they turn the sun
on again I’ll plant children
under it, I’ll light up my soul
with a match and let it sing....”
—Anne Sexton (1928–1974)
“It was you that broke the new wood,
Now is a time for carving.
We have one sap and one root—
Let there be commerce between us.”
—Ezra Pound (1885–1972)