Source : Webster's Revised Unabridged Dictionary (1913)

Lawsonia \Law*so"ni*a\, n. (Bot.)
   An Asiatic and North African shrub ({Lawsonia inermis}), with
   smooth oval leaves, and fragrant white flowers. Henna is
   prepared from the leaves and twigs. In England the shrub is
   called {Egyptian privet}, and in the West Indies, {Jamaica
   mignonette}.

Alcanna \Al*can"na\, n. [Sp. alcana, alhe?a, fr. Ar.
   al-hinn[=a]. See {Henna}, and cf. {Alkanet}.] (Bot.)
   An oriental shrub ({Lawsonia inermis}) from which henna is
   obtained.