Irises

Woottens Iris Encyclopaedia

Read on to find out more about Irises, the different species and how to grow them

The Iris genus includes over 300 different species these are split into two main groups that we can grow in the UK– Bulbous Irises and Rhizomatous Irises. Within these two groups there are many more categories, at Woottens we grow over 30 different species spread over the two groups, most of these can be seen in the table below in their retrospective groups.

As the name denotes a Bulbous Iris has a ‘bulb’ which is a set of modified leaves designed to be a storage organ for food. Whereas a Rhizomatous Iris has a ‘rhizome’ which is a modified stem, again designed to store the plants food.

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  Bulbous Iris bulb

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  Rhizomatous Iris

• The Iris flower has 3 upper petals are known as ‘standards’, 3 lower petals known as ‘falls’ and 3 inner petals known as ‘style arms’. Each fall as a marking at the top called a beard, or in ‘beardless Irises’ this is called a ‘signal’ – it is said to be an indicator to pollinating insects as to where to find the pollen.

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  Iris flower

Within different species the size of petals varies. For example, on a typical Bearded Iris the standards are tall, the falls long and the style arms short and tucked away on the inside of the standards. On a Japanese Iris – or Iris ensata the falls are wide, sometimes reaching 30cm in width and the standards are very short.