A favourite double delphinium with especially
perfect formal placement of the coloured bracts is 'Alice
Artindale' shown here. When the flower buds start
opening, they are beautiful, like perfect little rose
buds. The beauty fades as the flowers age because the
centres open. Curiously, plants of 'Alice Artindale' sometimes have flowers with distinct sepals and petals. These are fertile seed producers, whereas the double flowers are sterile.
Stunningly beautiful doubles occur in selections
of the red-flowered Californian species, D. cardinale
and similar doubles are also found among yellow variants.
Both types are fertile and come reasonably true from seed.
It would be interesting to know if these double forms of D. cardinale are tetraploid?
Tetraploid forms of red D. nudicaule x D. cardinale were used in crosses with garden hybrids to produce the 'University Hybrid' strain of red delphiniums. Many of these lovely plants raised by Professor R.A. Legro have fully double flowers.
A common feature of double flowers is an increase in the number of carpels and an open centre makes them obvious. This cluster of carpels is rather unattractive and spoils the flower, especially when the carpels become contorted as they develop.