Yellow Flag seedhead (Photo Copyright: gillianplummerphotography.co.uk)
When walking around the lake on campus at this time of year, chances are you will see a distinctive seed head amongst the foliage on the edge of the water.
This belongs to one of the two species of the Iridaceae family native to the British Isles, both of which are found on campus. Thanks to the lake on Reading University campus, we have the perfect habitat for the most brilliant of the two, Iris pseudacorus.
In the summer, these plants, with bright yellow flowers up to 10cm across, are one of the most striking on campus and certainly lives up to it’s common name of “Yellow Flag”
Yellow Flag flowers and leaves. (Photo: George Yatskievych www.discoverlife.org)
I. pseudacorus, is considered an aquatic plant as it prefers wet ground such as that of the edge of a lake, or more broadly speaking, wetland habitat where the plants may be partly submerged.
All flowers of the iris family are a very distinctive shape. They give an impression of being three separate flower heads but are in fact one flower made from 3 inner and 3 outer tepals (indistinguishable petal/sepals)
An interesting colloquial name for I. pseudacorus name is ‘Segg’. The name refers to the sword shaped leaves of the iris. The word itself translates to ‘short sword’ in Anglo-Saxon.
Images reproduced with permission of the authors.
The yellow flag iris is perhaps the nicer side of the genus. Iris foetidissima or Stinking Gladwyn is rather more notable for its smell.
Iris aside, many of the other members of the Iridaceae do not have the same shape of flower. Crocus, for instance, is also in the family and very unlike Iris in floral shape.