The purple spotted leaves appear in the spring (April-May) followed by the flowers borne on a poker shaped inflorescence called a spadix. The purple spadix is partially enclosed in a pale green spathe or leaf-like hood. The flowers are hidden from sight, clustered at the base of the spadix with a ring of female flowers at the bottom and a ring of male flowers above them. Above the male flowers is a ring of hairs forming an insect trap. Insects are trapped beneath the ring of hairs and are dusted with pollen by the male flowers before escaping and carrying the pollen to the spadices of other plants, where they pollinate the female flowers. The spadix may also (see the picture) be yellow, but purple is the more common.
In autumn the lower ring of (female) flowers forms a cluster of bright red berries which remain after the spathe and other leaves have withered away. The berries are extremely poisonous.
All parts of the plant can produce allergic reactions in many people and the plant should be handled with care. Many small rodents appear to find the spadix particularly attractive and it is common to find examples of the plant with much of the spadix eaten away. The spadix produces heat and probably scent as the flowers mature and it may be this that attracts the rodents.
Arum maculatum is also known as the cuckoo pint in the British Isles and is named thus in Nicholas Culpepers' famous 16th Century herbal. This is a name it shares with Arum italicum (Italian Lords-and-Ladies) - the other native British Arum.