Alice,

Orris root is Iris germanica v. florentina. It is thought to be a very old hybrid. It has a fairly good fragrance and, in a good soil, is moderately vigorous in growth. I have trouble growing it at home where the soil is less fertile.
I have read that other fragrant flowered varieties of I. germanica will produce Orris root. If that is so then let your nose be your guide. The rhizomes have to be washed and then dried for a year or longer. Fungi and/or bacteria do something to it like the cheese making process.
I have wanted to try the extremely fragrant and reblooming Iris 'Sugar Blues' to make Orris root.

Mike519

thanks mike519,
Are you saying that there may be no fragrance to begin with. Only after aging the root do they produce a scent?
thanks for responding.

Alice,

I have never noticed any fragrance when dividing the plants.
The Orris scent is similar to violets, according to the herbals.
I will look at Grieves Herbal and get back to you.

Mike

Alice,

The following information comes from A Modern Herbal by Mrs. M. Grieve F.R.H.S., 1931, Pub. by Barnes & Noble ISBN 0-88029-921-5

If I had only one book on herbs and ethnobotany, it would be this one.

Fresh roots have an earthy smell, the characteristic violet odour is gradually developed during the drying process and does not attain its maximum for at least two years, and even intensifies after that time. (classed as a fermentation oil).

When fresh, the rhizomes are extremely acrid and when chewed excite a pungent taste in the mouth which continues for some hours. (Iris are poisonous if eaten)
This acridity is almost entirely dissipated when dried, the taste then being slightly bitter and the smell agreeable, closely approaching that of violets, though in the fresh state the rhizomes are practically odourless. The loss of acridity appears to be due to the disappearance of a volitile acrid principle on drying the rhizome.

(The three species involved in growing Orriis root are Iris germanica, I. germanica variety Florentina and I. pallida. All three are very similar and probably related.)

The planting of Orris root in Tuscany is of great importance and is known locally as 'giaggiolo'

Mike519