I just had to look it up, repeat-blooming Catts (beyond twice a year) being not very common. Bingo... 1/4 C. forbesii. That species is a flower machine, and clearly it imparts that to its hybrids. I'm sure B. nodosa helps too, also produces flowers over an extended period.
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"Extraordinary claims require extraordinary evidence" Carl Sagan
To be exact, each lead seems to have 2 growths / flowers per year. The entire plant, however, seems to be sending out new growths at different parts of the year. I have three divisions of this plant and they all seem to have a mind of their own, growing and blooming at different times of the year...
C. forbesii does growths/roots/flowers 2 or 3 times a year, each time producing a couple of new growths that may bloom successively. So it is a fantastic bloomer (even if unspectacular flowers), also cold-tolerant. I have C. Quinquecolor (forbesii x aclandiae) that has the multiple bloomings and cold-tolerance of forbesii with color and fragrance from aclandiae - sort of the ideal primary for my outdoor growing.
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"Extraordinary claims require extraordinary evidence" Carl Sagan