Picea mariana'Nana' is very popular, dwarf, flattened, cushion-shaped selection of black spruce, with uniform layered branching, and dusty, bluish green needles. After 10 years of growth, a mature specimen will measure 15 to 18 inches (38 - 45 cm) tall and 24 inches (60 cm) wide, an annual growth rate of around 2 inches (5 cm).
This conifer is a very old part of the nursery trade, unfortunately of unknown origin. It's apparent first mention was by Ludwig Beissner in his 1884 book, Handbuch der Nadelholzkunde.
Picea mariana 'Nana' in the Gotelli Collection at The U.S. National Arboretum, Washington, DC; May 2006.
Photo by Dax Herbst
Picea mariana 'Nana' — a closeup of foliage detail. Photo copyright of The Wildlife & Conifer Garden Donated by Don and Nonda Surratt, Ohio, USA.
Photo by Nonda Surratt
Picea mariana 'Nana' in a private garden in Olympia, Washington, seen during the ACS WR conference, September, 2013.
Photo by Sean Callahan