Gloriosa contains only one species: G. superba. It is native to tropical Africa and Asia. There is some discusssion about how many species and varieties the genus contains. Nowadays it is considered that there is only one species which contains various, let's say, growing forms. The differences concern mainly the colours and shapes of the flowers. Others take the view that there are more species, besides G. superba.
Like Gloriosa Sandersonia contains only one species: S. aurantiacum. It has its habitat to South Africa and is commercially grown in New Zealand.
If you put the tubers of Gloriosa and Sandersonia next to each other, you see the similarity. The tubers of both plants are elongated and are in diameter almost round. The tuber is beige to brown coloured. At the end of the tuber the new bud is situated. The small bud produces the next growing season an up to one metre long stem. The corm has only one bud. If this bud gets damaged, it will die and there will be no plant! So take in storage special care for this bud and when you plant the tuber. The tuber is planted vertically, with the bud down and the top of the tuber just below the surface of the soil. You have to use a rather high pot, because the new tuber is formed at the underside of the old tuber.
Both species form a climing stem with ovate to lanceolate leaves. The plants have often tendrills at the end of the leaves.
The most important differences between the two genera are the flowers. The flowers of Sandersonia are born in the leaf axils of the upper part of the stem. They drooping flowers are orange coloured and bell- or balloon-shaped. Before a Gloriosa flowers, the stem branches. At the end of the branched stems the flowers appear. It's difficult to describe the flowers and their beauty. You have to see it for yourself. But, let me try it. The six tepals are narrow, wavy at the edges and re-curve to expose the stamens and the ovary with its three-cleft stigma. The lenght and width of the tepals can vary, as well as their colours. Some flowers are orange to red with yellow edges, while others have only are red central band and are further yellow, or the upper half is red and the bottom part is yellow. A friend of mine told me once that there should exist a complete white flower. I have never seen such a plant.
Something about the cultivation.
Neither species are very difficult to grow. During the dormant period the tubers are stored in the old, dry soil at a temperature of 5-15ºC. By storing them this way, the growing bud can't get damaged. In April the tubers are planted into new soil. The pot is placed on a warm and sunny spot. The soil is kept mosture during the growing period. I fertilize the soil once every three weeks. When the plant withers, the watering is stopped.