The writer's experience in combating sterility in inbred Amaryllis strains has suggested experimentation with hybrids between genera. One cross that was apparently successful used a free-blooming clone of Sprekelia formosissima superba as seed parent and a vigorous form of Habranthus robustus as pollen parent.
Seedlings are very uniform in appearance and growth habit. In two years of growth in a cool greenhouse, the leaves reached a mature height of 14 inches and a width at the base slightly exceeding 1/4 inch. Maximum width at a height of 10 inches is 3/8 inch. The leaf shape resembles Sprekelia, but the size is smaller than either parent. The color of the foliage is dull medium green.
Semi-dormancy occurs in winter. However, blooming does not seem to be
clearly related to dormancy. Three of the bulbs have bloomed to date, all
at different times, even though all were grown in a community pot. Next
season, the plants will be forced into deeper dormancy to encourage free
In Plant Life, volume 25, 1969, the author reported the first blossoming of an intergeneric hybrid of Sprekelia formosissima and Habranthus robustus. Since that report, the bulbs of X Sprekanthus cagei Traub have fully matured, and further observations on culture and growth habits can now be made.
Also, chromosome studies on the plant have been made by W. S. Flory and his associates at Wake Forest University. These studies tend to confirm the opinion that genus Sprekanthus Traub is a true bigeneric hybrid and they tend to clarify the apparent complete sterility. The predominant count is 2n=66 in Sprekanthus Traub although some variation was found in chromosome numbers from cell to cell, which seems consistent with the variation found in the 120-chromosome race of Sprekelia. In Sprekelia, the count is 2n=120, and in Habranthus it is 2n=12. With 60 chromosomes from one parent and six from the other, viable crosses or selfs would seem improbable.
However, chromosome doubling in Sprekanthus, would be extremely interesting. Dr. Flory has suggested procedures for treatment with colchicine, and the author is presently trying to produce polyploidy. A tetraploid of the plant would hopefully be fertile.
Sprekanthus cagei grows and blooms well in the garden anywhere the soil does not freeze. Outside, its blooming habit is similar to that of Habranthus, but the scarlet blossoms, with just a hint of violet, are much prettier than Habranthus in the opinions of most people. Also, the segs are wider and the shape more graceful than in Sprekelia. Compared with Sprekelia, Sprekanthus blooms more freely and makes a much better recurrent-blooming pot plant. Every few months, the pots can be kept dry for a month to initiate bloom.
Sprekanthus forms many offsets, which can be grown to blooming size
in about one year. The bulb could become commercially important. Cuttage
has not yet been tried for propagation. A few mature bulbs will be made
available in the fall of 1971.