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) QCD). This gives rise to an effective mass for the quarks, often identified with the valence quark mass in QCD. Analysis of experiments indicate that the current quark masses of the lighter flavours of quarks are much smaller than the QCD scale, Λ, hence chiral flavour symmetry is a good approximation to QCD for the up, down and strange quarks. The success of chiral perturbation theory and the even more naive chiral models spring from this fact. The valence quark masses extracted from the quark model are much larger than the current quark mass. This indicates that QCD has spontaneous