Briefly,
English plantsman,
Eric Smith created a special group of
blue-green hostas in the 1960s from a chance cross of what was
then called H. sieboldiana 'Elegans' (now just 'Elegans')
and H. 'Tardiflora'. At first, he only numbered the
seedlings which were later named by him and others.
From the first cross, Smith
select 4 outstanding blue-green seedlings. When these reached
maturity, he crossed them with each other and saved 27 from the
second generation. The third generation of cross breeding added
only one plant. These 32 hostas are now known as the
Tardiana
Group. The
name "Tardiana" is a composite word taken from the "Tard"
in 'Tardiflora' and the "iana" from 'Sieboldiana'.
The system he used had the format of TF 1 x 2 where the first
number indicated the generation and
the second number was for the individual
seedling. So, the example would indicate the second plant
selected from the first generation of crosses.
Click Here for greater
detail on the Tardianas.