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sap,fluid in plants consisting of water and dissolved substances. Cell sap refers to this fluid present in the large vacuole, or cell cavity, that occupies most of the central portion of mature plant cells. The term sap is generally applied to all the fluid that travels through the vascular tissues (xylem and phloem) of higher plants. Water containing dissolved minerals enters the plant through the root hairs by osmosis and is transported upward through the xylem to the parts containing chlorophyll, usually the leaves. There, large amounts of water leave the plant by transpiration, although some is used in photosynthesis to produce food materials. The phloem carries the resulting highly concentrated colloidal solution down to the other plant parts for storage. Sap ascends at a rate of from 1 to 4 ft (30–122 cm) per hr; in the coast redwood it rises easily to a height of almost 400 ft (120 m). The exact mechanisms behind this enormous lifting force are not certain, although several principles are thought to be involved. Chief among them is the pull of transpiration; as water evaporates from the leaf cells, they draw in liquid osmotically from the xylem tubes to replace it. Because of the great cohesiveness of water molecules, the resulting tension affects the entire continuous column of water down to the root tips, which in turn absorb more water from the soil. Root pressure is another factor, although it can force the sap up only a limited distance and operates chiefly in the nongrowing season, which explains the sap flow when a leafless tree is tapped in winter. Atmospheric pressure and capillary attraction are minor factors. The sap of some plants (e.g., sugarcane, sugar maple) contains much sugar and is an article of commerce. The name sap is sometimes applied to latex (e.g., rubber), resin, and other specialized plant fluids.
What does it mean when you dream about sap?
The vital juices of plants and animals, sap represents bodily health and vigor (the sap of youth), which is why someone who feels depleted is “all sapped out.” Like the sap from the maple tree, someone who is excessively gullible or sentimental is “sappy” (sweet, syrupy).
SAP(1) (SAP America, Inc., Newtown Square, PA, www.sap.com) The U.S. branch of one of the world's largest software companies, SAP AG, Walldorf, Germany. SAP was founded in 1972 as Systems, Applications and Products in Data Processing by five former engineers from IBM. SAP's R/2 mainframe and R/3 client/server business application suites were the flagship products for the company, catapulting the company into prominence in the 1980s and 1990s. Today, under the banner of the SAP Business Suite, SAP is a leading vendor in enterprise resource planning (ERP) and other enterprise business software.
In 2010, SAP acquired Sybase, maker of the popular Sybase database and related software. See SAP Business Suite, R/3 and Sybase.
(2) (Session Announcement Protocol) An IETF protocol for distributing session description messages to potential recipients. It is widely used to send SDP messages. See SIP.
(3) (Service Advertising Protocol) A NetWare protocol used to identify the services and addresses of servers attached to the network. The responses are used to update a table in the router known as the Server Information Table.
( 4) (Secondary Audio Program) An NTSC audio channel used for auxiliary transmission, such as foreign language broadcasting or teletext.