In my experience book indexes are often unsatisfactory in one or more ways - for example by listing English Stonecrop as "English Stonecrop" but not as "Stonecrop - English Stonecrop". And you have to stick one or more of your fingers in the book while using them!

Seriously scarred by the different indexing approaches used in different books we've tried to make sure that ours is as comprehensive as possible. 

And, being software, it hyperlinks directly to images which appear in the right-hand window. Here we've clicked on "Marsh Violet" (which you can also find as "Violet - Marsh Violet"). There is also an index of scientific names, a flower family index, plus a fourth index which links directly to Gallery photos.

There are indexes of Common names, Scientific names, and of Families

Index heaven!

NOTE: The picture on the right is only an illustration - the buttons don't work!