I think the ingredient ratio of alkaloid composition may be more than essential oils and this made the classification according to alkaloid family.

in mentioned example the amount of  essence is more than alkaloid 

Categorization of plants is based on several criteria, one of it being its human use for e.g. food crops, vegetable crops, horticulture crops etc. Many medicinal and aromatic plants have both uses and can be classified in either or both these categories. Some plants have multi-uses and can be included in several classifications. Is there any problem in categorizing Ruta graveolens either as an essential oil or alkaloid bearing plant? If you chose you can categorise it as medicinal-cum-aromatic plant. Many spices possess essential oils but are more popularly classified as spices.

thanks,  do you see R, graveolens in any essential oil list?

We have Ruta graveolens plants in our Institute and as far as I rember my colleagues from Pantnagar Research Center published a paper on its essential oil composition. You may contact Ram Swaroop Verma or Rajendra Padalia who are on Researchgate in case you are interested in the composition. I did not understand what exactly you mean by essential oil list? In case you want to check the names of plants which contain essential oils, you may search journals which specialize on essential oil plants e.g. Journal of Essential Oil Research, Journal of Essential Oil Bearing Plants, Flavour and Fragrance Journal etc. Dr. Brian M. Lawrence, the former Editor-in-Chief of Journal of Essential Oil Research published a book on essential oil profiles of several aromatic plants (Compilation of his columns published regularly in Perfumer and Flavorist Journal).

You may also consult 6 volumes book (Essential oils) written by Ernest Guenther for plants containing essential oils.

thanks a lot

Dear Dr. Saeid

If this is not too late, the number of estimated aromatic plants in the world ranges from 17500-20000. Around 3000 essential oils are produced in different countries, which means that other aromatic plants have not been commercialized yet. Over 400 essential oils are traded in the international market. Ruta graveolens possibly is listed in one of the 3 categories. In addition to essential oils, hydrosols or hydrolats or condensate waters or distillation waters which are by-products of aromatic plants' distillation are used in flavoring and aromatherapy industries. In India rose water is used in functions and ceremonies and ajowain (Trachyspermum ammi) water is used as a carminative. Ocimum sanctum leaf water is administered to persons on the death bed with the hope that it cleanses the sins of the person and keeps evil spirits at bay.

I hope this provides some clues regarding the list of essential oils.

Best wishes and good luck.