ARUM LILIES – PART OF A COMPLEX ECOSYSTEM

By Dr Anina Lee

Most of us living in the Western Cape (or other parts of southern Africa) are very familiar with Zantedeschia aethiopica, the beautiful white arum lilies that grow in marshy places along streams and wetlands – and in most suburban gardens.

However, if you live in Western Australia, you would not be thrilled to see them, as they have been declared an invasive alien weed there.

The plant is thought to be named after an Italian physician/ botanist called Giovanni Zantedeschi, and the word ‘aethiopica’ once referred to anything south of the known world in classical times. The origin of the Afrikaans name ‘varkoor’ (pig’s ear) is much more obvious.

The arum lily is one of the host plants for Hippotion celerio, commonly known as the silver-striped hawk moth or grape vine hawk moth.

PHOTO: BioLib.cz

The arum lily is not a true arum (belonging to the genus Arum), nor a true lily (belonging to the genus Lilium). But it does belong to the family Araceae – hence the name arum. But we love them and will call them whatever we wish.

The arum lily flower is not what it seems. The big white funnel-shaped ‘petal’ is actually not a petal, but a modified leaf called a ‘spathe’. The minute flowers are arranged in an intricate spiral pattern on the yellow finger-like spine inside the spathe, called a ‘spadix’. The flowers are arranged in such a way that the male flowers appear on the top section of the spadix, and the female flowers on the lower third. The spadix is at first creamywhite and matures to bright yellow.

Click below to read more. (The full article can be found on page 8)