Pinus sylvestris 'Nana'

The name Nana means dwarf.
Gerd Krussmann in Manual of Cultivated Conifers staes 'Dwarf form, small, bushy, only about 50cm high, very densely branched, twigs very short, needes about 3 cm long and Blue-green.'

Krussman points that the cultivar Watereri is often improperly sold as Nana.

Conifers The Illustrated Encyclopedia has a good picture of a very large, old specimen. The caption with that picture states that Nana grows much slower than Watereri.