The seeds and leaves of the fennel plant both have a licorice flavor, although the flavor of fennel is milder and somewhat sweeter than anise. Fennel seeds are actually a spice, although the leaves, stalks and roots of the plant are known as a herb.
Definition of air mass. : a body of air extending hundreds or thousands of miles horizontally and sometimes as high as the stratosphere and maintaining as it travels nearly uniform conditions of temperature and humidity at any given level.
The primary classification of air masses is based on the characteristics of the source region, giving Arctic (A) , Polar (P) or Tropical air (T) , and on the nature of the surface in the source region: continental (c) or maritime (m) .