Are there any large cultivars for the garden?
I had to look that one up. Interesting-looking plant! Unfortunately, they would hate growing in my warm climate. And I have no useful information to give you about them, jujujojo. Hopefully someone more familiar with them can help out.
yes, the are known as megaherbs and are members of the apiaceae family (my favourites) and are available from rarepalm seeds and also can be bought off ebay from a lovely chap called Bob Todd - Choice Plant Seeds, will ship to US.
Aka as Campbell Island carrot