A LEXICON called Gardener's Latin by Bill Neal (Robert Hale, pounds 6.99) aims to make sense of botanical plant names. Species names are often useful in pointing you towards the outstanding characteristic of a plant; or would be, if we could translate them. This book gives the interpretations. Anything that ends in folius describes the leaf, as in Hellebore argutifolius, a hellebore with a sharp-toothed leaf. Flora names, as in Salvia confertiflora, have to do with the flower; this name means 'with crowded flowers'.