lions leaf

from The Collaborative International Dictionary of English v.0.48
Lion's leaf \Li"on's leaf`\ (l[imac]"[u^]nz l[=e]f`) n. (Bot.)
   A South European plant of the genus {Leontice} ({Leontice
   leontopetalum}), the tuberous roots of which contain so much
   alkali that they are sometimes used as a substitute for soap.
   [1913 Webster]
    

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