I have to admit, I have a prejudice against Cunningham's herbal works. In my opinion, the existence of the Encyclopedia and the earlier Magickal Herbalism has held back the study of magickal herbalism for about ten years. During that period, not only were older magickal herbals allowed to go out of print and no new ones published, but most Llewellyn works shamelessly borrowed Cunningham's descriptions. The descriptions given in this volume are short and sometimes misleading, and betray a heavy reliance on Culpeper.
On the other hand, the Encyclopedia is a fine basic reference work, if one written by someone who appears to have spent more time in the library than in the garden or stillroom. For each herb, spice, or magickal plant, folk names, gender, planet, element, deities, powers, and magical uses are given. Tables of gender, planetary rule, elemental ruler, and magical intentions are given, and a cross-reference to folk names. Listings of powers are short and perhaps overgeneral, but elaborated in the concise "magical intentions" section. The volume is an excellent complement to its predecessor, Magickal Herbalism, and students should possess and study both.
Note: Users should double-check all proposed uses of herbal materials based on this work in a reputable modern herbal for danger. (For instance, though cinnamon oil was used as an anointing oil in ancient times, modern oil is too strong for use on skin.)