May - Orris-root – Iris florentina
April this year has not only been very dry but it has also been cold so the striking pale blue flowers of Iris florentina are flowering later than usual. However, the opening buds can now be found in various corners of the Physic Garden. This plant is cultivated as an ornamental plant in temperate regions almost worldwide. It was also grown to produce orris-root, a scented substance used in perfumes, soaps, tooth cleanser and clothes washing powder as well as medicinally as an expectorant and decongestant.
It is a rhizomatous perennial originally from southern Europe mainly Italy (including the city of Florence) and France. It has a thick, violet scented rhizome, sword-like grey-green leaves, that are semi-evergreen, a tall branched stem and many pale flowers in early summer. The plant was introduced to northern Europe in 1500 where it has been cultivated for many centuries.
Orris-root is produced by drying the violet scented rhizomes which are then ground. It is still used in cosmetics, perfumes, soaps and sweets, also for maturing Chianti wine and as an ingredient in Bombay Sapphire Gin. It is however, no longer used medicinally. The juice extracted from the flowers also had a use during the Middle Ages. The pigment produced called ‘Iris green’ was valued by manuscript illuminators and painters.
Like many other irises most parts of the plant are poisonous, if ingested and can cause stomach pains and vomiting. Beware handling the plant may cause a skin irritation or allergic reaction.