Monday, August 20, 2012

Arum Lily

In response to Diana's question - “What is your big-leaved plant?” Mine would have to be the White Arum Lily.

Zantedeschia aethiopica, commonly known as Arum Lily in South Africa, Calla Lily in many places and sometimes Easter Lily in England and Ireland. It is however not a lily but comes from the Aracaea family which also includes Anthuriums, Philodendrons and delicious monsters.

Common to most members of this family is a modified leaf known as a spathe. This is the part that most us would think of as the flower petal.

Beautiful white spathe

Unopened spathes are pale green

The actual flower is a cluster of minute flowers on a central column known as a spadix. On Zantedeschia aethiopica the top part bears male flowers and the bottom carries the female flowers. About ¾ of this spadix carries male flowers.

Yellow spadix on Zantedeschia aethiopica

The common Arum originates from South Africa and is found from the Western Cape all along the coast, even spreading as far as the Northern Province. This vast range covers a wide variety of climatic conditions, from salty coastal air to chilly high altitude mountains. It will grow and flower in winter and summer rainfall areas. If it remains moist all year it will remain green, yet if it naturally receives no water in the dry period it will die back. It's large underground rhizome allows it to spring back to life as soon as the rainy season begins. Being tolerant of so many growing conditions makes Zantadeschia a very obliging garden specimen. They tend to grow taller and carry larger leaves in shady conditions, in sun the leaves are smaller but they flower more prolifically.

Typical large leaf in shady conditions

I have them in a number of different areas in my garden and those that receive water from my rainwater tanks in summer remain evergreen and flower sporadically throughout the year. The others disappear and remain dormant in our hot, dry and summer but grow incredibly fast as soon as the winter rains begin.

It is also a great plant for wildlife, attracting numerous flying and crawling insects, including bees and my favourite crab spider. In the wild the rhizome is eaten by pigs and porcupines, luckily none of those in my garden, but the snails do have a feast. The berries which turn yellow when ripe are eaten by birds which aid seed dispersal.

Unripe fruit 

The leaf on the right almost totally demolished by snails.

Definitely worth planting if you live in it's natural range. Although popular in many parts of the world, plant with caution, in Western Australia it has become a weed.