Flowers of Oxalis tetraphylla (Four-leaved Pink-sorrel) photographed in infrared.
In visible light the the petals are strongly veined, with the veins leading back to the centre of the flower. In infrared light this veining is still visible, but much less pronounced.
Four-leaved Pink-sorrel is commonly grown as an ornamental plant for its foliage, remsembling a four leafed clover with a dark colouration around the base of each leaf. It is sometimes known as "Lucky leaf" or "Four-leaf Clover" for this reason, though it is not related to clovers.