Hi, Tanacetum is Tansy,Pyrethrum as used as herbicide is
Pellitory(Anacyclus) although it is often spoken as a different variety,
Pellitory persia(chrysanthemum roseum)strangely enough chrysantemum ,this
is the variety I use as herbicide.To confuse matters Fever few is also
Pyethrum and this is the Pyrethrum I use medically.What do you wish to
achieve with it.
tony (aka. warlock)