there are lots of topics in this link with information on - herbs, Agriculture and Australian native

http://www.uq.edu.au/_School_Science_Lessons/SchoolAgProjects.html#HerbsH

AND WELL YOU MAY ASK

WHAT EXACTLY IS A HERB?

Botanically speaking, a herb is: “A perennial plant whose stem is soft and dies down to the ground after flowering”.

However, such a narrow definition excludes plants currently considered by many of us to be herbs. For example, Bay leaves are used for culinary purposes and are thought by many of us as a herb, but the Bay is in fact a tree.

And when is something a spice and when a herb? Wikipedia says: “A spice is a dried seed, fruit, root, bark, or vegetative substance primarily used for flavouring, colouring or preserving food. Spices are distinguished from herbs, which are parts of leafy green plants also used for flavouring or as garnish”.

To many of us, much of the description given here for a spice would also apply to a herb. Even within the Queensland Herb Society we prefer to blur the lines a little and feel that herbs are much, much more than just “leafy green plants used for flavouring or garnish”! Many herbs have amazing medicinal qualities too.