the following is a detailed botanical description of the new ‘ teardrop ’ variety : propagation : holds its distinguishing characteristics through succeeding propagations by asexual reproduction , specifically by grafting . growth habit : branches are formed with slow growth at exceedingly narrow , acute angles relative to the trunk , resulting in a tree with a narrow , dwarf , conic figure . branches are strongly ascending and maintain their position with increasing age . the canopy is much narrower and more dense than that of a tree typical of the species . vigor : the growth rate of this tree is less than the species , and is exemplified by growth of about 6 to about 12 inches of terminal growth per year . a typical twelve year old specimen is about 9 feet in height . needles : the needles of this tree are approximately 0 . 5 inches longer than other observed members of the species . the needles are also slightly thinner and therefore more flexible than needles from other observed members of the species . upper surface color rhs 137c graduating to rhs 138b from fascicle base to needle tip . lower surface color rhs 138b graduating to rhs 138c from fascicle base to needle tip . the needle length of pinus nigra ‘ teardrop ’ is typically about 4 - 4 . 25 inches including sheath . the length of the sheath is typically about 0 . 25 - 0 . 33 inches . both are longer than the common species form of pinus nigra ( unpatented ) which has an about 3 . 5 inches overall needle length and a sheath length of about 0 . 15 - 0 . 25 inches . pinus nigra ‘ teardrop ’ has double needles joined at the sheath and a concave needle shape . the needle margins are smooth and are typically persistent up to about 10 months . the common species form of pinus nigra also has double needles joined at the sheath with a concave needle shape . the needle margins of the common species observed as of this time are also smooth but the needles are typically only persistent for a period of 8 months . the apex of the needles of pinus nigra ‘ teardrop ’ is pointed , needle - like . angle .— the branches of the ‘ teardrop ’ variety are whorled , strongly ascending , and form an angle ( measured from the horizontal ) of from about 50 degrees to about 75 degrees . the angle ( measured from the horizontal ) of other known pinus nigra specimens ranges from about 10 to about 35 degrees . the angle of the ‘ teardrop ’ variety causes a compact growth habit against the trunk , and creates a slender crown . size .— other specimens of pincus nigra have branch sizes ranging from about 12 inches to about 24 inches in length and the new branches are from about 0 . 5 to about 0 . 75 inches in diameter . the ‘ teardrop ’ variety displays branches from about 6 to about 12 inches in length and new branches are from about 0 . 75 to about 1 . 0 inch in diameter . bark : the surface texture of the bark varies by age . immature bark is smooth and typically only broken by the shape of the lenticels and foliage abscission scars . mature bark is rough and scaly . bud : the shape of the apical bud of the new tree is narrowly conical with the secondary buds somewhat elliptical . the secondary buds typically surround the apical bud in concentric whorls . the apical bud is typically about 1 . 0 inches in length with the secondary buds typically ranging from about 0 . 5 - 0 . 75 inches in length . the surface texture of all buds is smooth and somewhat glabrous . the buds are smaller than the common species form of pinus nigra . the typical color of apical buds is rhs 155d and a typical color of secondary buds is rhs 176d . disease and pest resistance : not observed to be any different than common pinus nigra trees growing in the area . hardiness : not determined . observations are of trees growing in the willamette valley of oregon ; hardiness zone 5a per usda hardiness zone . a few trees have also been growing in wisconsin and have not suffered any adverse affects from two wisconsin winter seasons .
a distinctly attractive pine tree in the pinus nigra family with a dwarf , narrow , conic to columnar appearance , having dense branching , which forms a tall , slow growing , narrow specimen that can be planted at high density for effect and landscaping .