Fennel similar spices – anise, star anise, and coriander. In 2014, India produced 60% of the world total of fennel, with China and Bulgaria as leading secondary producers (table). Many species in the family Apiaceae or Umbelliferae are superficially similar to fennel, and some, such as poison hemlock, are toxic, so it is unwise, and potentially extremely dangerous, to use any part of any of these plants as an herb or vegetable unless it can be positively identified as being edible. Dill, coriander, and caraway are similar-looking herbs, but shorter-growing than fennel, reaching only . Dill has thread-like, feathery leaves and
Flavour (particle physics) description of the flavour symmetry is described by a chiral group . If all quarks had non-zero but equal masses, then this chiral symmetry is broken to the "vector symmetry" of the "diagonal flavour group" , which applies the same transformation to both helicities of the quarks. This reduction of symmetry is a form of "explicit symmetry breaking". The amount of explicit symmetry breaking is controlled by the current quark masses in QCD. Even if quarks are massless, chiral flavour symmetry can be spontaneously broken if the vacuum of the theory contains a chiral condensate (as it does in low-energy