I found that it is similiar to hippeastrum. One being from south africa and the other from south america. Here Amaryllis Belladona naked ladies are as common as mud, you buy them at the supermarket. These multiflora clones have made their way around the world and are now back in South Africa. Often called Bidwill hybrids, they are far more robust than the wild clones.
Flower colours are unnamed but include white, pink and red.
Winter flowering and need to be kept dry in summer. Flowers in autumn. Somewhat limited stock. Minimum size 100 mm circumference. I've bookmarked them.