Infrared photograph of Epilobium palustre (Marsh willowherb) in flower.
In infrared light the petals of the flowers appear slightly brighter than they do in visible light. Veining on the petals that is apparent in visible light is still present when viewing the flower in infrared. The main difference in the plant's appearance in infrared is that the seed capsule, stalk, and leaves all appear much brighter than they do in visible light.
The flowers are very small, approx 0.5mm in diameter.They have four light pink petals with a notch in the centre edge of each petal. The seed capsules are several centimetres long and covered in short fine hairs.