Iris pseudacorus [Yellow Iris]

[nfoto]

Rørslett, B. 2013. Iris pseudacorus L. (Iridaceae). Yellow Iris. Flowers photographed in visible and ultraviolet light. http://www.ultraviol...us-yellow-iris/

 

Iris pseudacorus L.

NO: Sverdlilje

SE: Svärdslilja

DK: Gul Iris

FI: Keltakurjenmiekka, Kurjenmiekka

DE: Sumpf-Schwertlilie

EN: Yellow Iris; Yellow Flag

 

This is a tall, up 2 m high, plant native to Europe and western Asia. It is typical for nutrient-rich biotopes along lake borders, rivers, and wetlands. Although generally considered an aquatic species, I. pseudacorus rarely grows to depths more than 0.5 m.

 

Flowering is in June and ends in early July. The large conspicuously zygomorphic flowers are borne on terminal inflorescences and are eagerly visited by larger pollinators such as bees and bumblebees. The inner parts of the flower where style and anthers are present requires a visitor with sufficient weight and strength in order to gain access. Pollinators land and alight from the coloured patch immediately below the entrance to the flower.

 

Image reference: IRIS_PSE_I1107057336_VIS.jpg

Visible light: NIKON D3S, 125 mm f/2.5 Voigtländer APO Macro-Lanthar, daylight.

 

Image reference: IRIS_PSE_I1107052837_UV.jpg

Ultraviolet light: NIKON D200, UV-Nikkor 105 mm f/4.5 lens, Baader U2" (Venus) filter, SB-140 flash.

 

I. pseudacorus, in common with some other Iris species such as I. danfordiae (http://www.ultraviol...-danfords-iris/), exhibits flowers with a multi-coloured palette under UV illumination. The false-colour differentiation appears as yellow and blue-coloured parts of the tepals. In particular, buds and abaxial sides of the flowers have areas rendered in blue hues while the adaxial side is rendered yellow. The base of the lower tepal ("flag") carries a prominent darker UV patch. There are well developed conical cells along the major veins as well.

 

 

[Published 25 Apr 2013]