This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
This is a charming hardy perennial from the plains of Siberia, and will grow freely in any ordinary soil, and form large spreading tufts of rich blue flowers about 12 inches in height, with from four to eight flowers on each tuft. A fine example of this could have been seen a few weeks ago on Mr Barron's herbaceous border at the Chiswick Gardens. When I saw it, it was in full bloom, and, for aught I know to the contrary, it may be equally attractive now. It also, for the rich hue of its flowers, should be in every collection.