|Abies lasiocarpa or Rocky Mountain Fir, is a very large evergreen, reaching 100 to 160 feet tall, with a typical spire form. The needles are pale blue-green above, silvery gray below. The bark is a pretty gray or chalk-white. The 2- to 4-inch cones are dark purple and cylindrical. Native from Alaska to Oregon, Utah and northern New Mexico. This fir grows best in an acidic soil and cooler climates. 'Hexenbesen' has a tight, round growth habit. It has very dense foliage on tiered, horizontal branches.