I wish I'd checked to see what the name for this plant was, but I think this is accurate. Gotta love the Arboretum. Picture is also from previous visit. Distintctive shaping and structure identifies this plant.
Growing in wetland, among long grasses and flax.
These lilies are growing extensively in shaded gullies and wetlands on our property.
The flowers have a small yellow stamen at the centre, smaller than for cultivated Arum lilies, and the petals are white with green around the tips, unlike the cultivated lilies which have pure white petals.
Zantedeschia aethiopica (common names calla lily, arum lily; a.k.a. varkoor, an Afrikaans name meaning 'pig's ear') is a species in the family Araceae, native to southern Africa in Lesotho, South Africa, and Swaziland.