Hamburg parsley, sometimes known as turnip rooted parsley or parsnip rooted parsley is a real novelty in the UK which you are unlikely to be able to try unless you grow your own although it is much more popular in (obviously) Germany but also other parts of Europe.
There isn’t much left on the allotment at this year other than some hardy brassicas, leeks and parsnips. Parsnips are sometimes shunned by allotmenteers as they have to be in the ground for a long time to form good roots and always taste best after the first frosts. Some varieties need a very deep fine sandy soil to cope with their long tapered roots and show growers will grow them in dustbins or drainpipe. If your soil is less than ideal, you want to find a slightly shorter variety. White Gem is a good one to consider growing in that case
This is an absolute beast of a parsnip that lives up to it’s name. An RHS award winning parsnip at the time of publishing the roots when mature can get to a good 10 cm across and might win you a prize in the biggest parsnip competition.
The Student is a heritage parsnip developed around 1850 by James Buckman originally as an experiment to prove that existing strains could be improved by crossing with a wild parsnip. The results were so good that you can still buy the seed today.