Arboriculture Terms

small pores. between two guard cells on the undersides of leaves and other green plant parts. through which gases are exchanged and water loss is regulated.

knot. usually a figure-S knot. tied in the end of a line or in the tail of a knot to prevent the end or tail from passing through the knot.

water originating from precipitation (rain or melting snow and ice) that flows above ground rather than infiltrating into the soil. May occur if soils are frozen or saturated or if the rate at which precipitation falls is greater than the infiltration rate of a soil.