Garden Designers & Landscape Gardeners
Garden Buildings in South & East England

Zantadeschia aethiopica.
Right - in damp conditions 'Lily Of The Nile' will spread on a creeping root system to make dense mounds of leaves that can be up to 50cm long and 30cm wide. It is native to South Africa where it grows in large drifts in open meadow locations. In warm and wet conditions it's leaves will remain evergreen, looking gradually more dishevelled the lower the temperature until at about 2 or 3c they will have mostly died back. We have grown this plant in many different garden and found it to be very hardy, growing back reliably even after being reduced to a herbaceous state by a cold winter. See some plants growing well in jungle conditions with root competition in the London Tropical Style Small Garden. There are many different forms that will be added to the directory at a later date.
Right - Zantadeschias are members of the 'Arum' or 'Aroid' Araceae family and have a typical flower structure which consists of a yellow spike shaped spadix which bears tiny male and female flowers. The large white spathe is not technically part of the flower at all but a modified cowl shaped bract (a layer of leafy material that wrapped around the flower when it was emerging). 
Although it is not a lily or part of the Cala or Arum genus the 'Cala or Arum lily' as it is commonly known is horticulturally an extemely valuable plant; it provides low level lush jungly foliage and flower, it is highly adaptable growing in dry conditions with some root competition or in wet soil, in shade or sun. In wet, rich soil and partial shade it will grow the biggest leaves, spread and have the darkest green lush foliage display. In full sun and dryer conditions it's leaves may be smaller, paler or a little yellowed, but it may flower a little more. Growing under trees with some root competition it may be a little slower and smaller in all its parts but it will still put on a good display, when there are few plants that will grow in those postions at all. When growing at it's best there are few plants of this size to match it and its only drawback is that the large leaves can be bent over on their stems in strong wind or if brushed against. 
In the UK it is not invasive but in warmer conditions it can be, in Australia it is classified as a noxious weed. It is poisonous enough in all its parts to kill livestock and children, containing a toxin that is extremely painful as well as causing many symptoms of illness. This should not lessen the appeal of this plant though as a fantastic garden specimen, as one would have to chew and swallow a mouthful that would instantly taste painfully acrid upon the sap making contact with any mouth part.
Many thanks to Skip The Budgie on flickr.com for the photos. See their link on our resources page.