Picea omorika 'Pendula' is a named cultivar of Serbian spruce whose status is arguably questionable. Humphrey Welch and Gordon Haddow, in their 1993 book, The World Checklist of Conifers; as well as Gerd Krüsssman's text from the same year, Manual of Cultivated Conifers, both forward the assertion that Picea omorika 'Pendula' is used as a name for a wide range of weeping Serbian spruces with many differing growth habits.
It appears now that a specific clone has been re-selected to carry this name - a narrow, upright, strictly weeping conifer with attractive Blue-green-silver foliage. After 10 years of growth, mature specimens will measure 10 feet (3 m) tall and 3 feet (1 m) wide, an annual growth rate of 12 inches (30 cm) or more.
It's impossible to know if this is the original selection and it's probably best if this collective of weeping spruces were relegated to "forma" status, i.e. Picea omorika f. pendula.
Keeping with historical perspective, German botanist, Fritz Kurt Alexander von Schwerin (1847-1925) first described this cultivar in 1920. It is thought to have originated somewhere in Europe.