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Friday, December 30, 2011

Picea pungens 'Glauca' - Colorado Blue Spruce

The Colorado Spruce is an evergreen conifer native to the Rocky Mountains. It is quite variable in habit, generally an upright pyramidal, slow to medium grower, 60' x 20' in urban areas, over 100' in its native habitat. Branches are perpendicular to the main stem and can either hang slightly or be strongly ascending. Usually branched to the ground unless cut off so people can use the area under the tree. Can be very full or open depending on the cultivar. Lots of cultivars are available and you will not likely be planting a seedling.



The evergreen leaves are linear, 1 - 1 1/4" long deep blue, very sharp pointed, held almost perpendicular to the stems. Leaves 4 sided so they roll between your fingers. Leaves are attached to the stem on a small bump or pulvinus that remains when the leaf falls. Blue can be very blue to only slightly blue depending on the cultivar. Notice the bud in this image, they are somewhat rosette like but not covered with resin like Fir trees.



Male cones are reddish colored in spring back from the tip of the branches.



Cones are light brown, 3-4" long x 1" wide. Scale tips are undulated and quite papery textured. Borne in large numbers near the ends of the branches and pendulous. Falling whole in one year.



Orangish brown colored stems and distinctly grooved.  After the foliage falls they are rough due to the pulvinus remaining. See image of leaves above to see the grooved twigs. Bark deeply fissured, brown and dark brown.



Lots of excellent cultivars, way too many to list, but some are dwarf, columnar, weeping, very blue.

Misidentification: not sure, if you will have a problem with this one, look at the leaves, the angle they are held from the stem (P. abies is green and held about 45 degrees to the stem).

Locations:
Quite a few around, none look that great, they really need a colder winter and warmer summer. Best over the hill or even better in Oregon.