Colorado Blue Spruce

Species name: Picea pungens var. hoopsii

Common name: Hoopsii spruce, Hoopsii Colorado Blue spruce

Location: Ontario

I had wanted to post back-to-back blogs to contrast the difference between spruces and firs, since many people when they're first starting out at plant identification (me included) have a hard time telling them apart. I didn't get a chance to post a blog yesterday and I had a different blog planned for today, so I guess I'll just have to post two blogs today :)

The Colorado spruce, as I'm sure you can guess, is native to the alpine regions of Colorado in the United States. It has been transported all around the world by humans, favoured for its blueish tint to the needles at the tips of the branches. As the branch grows and the needles age, they lose their waxy frosting that gives them the blue tint, and turn green. The Colorado spruce is very intolerant to shade, and so the needles on the inside of the tree are shed as they become too shaded by branches above them. While the Colorado spruce is a popular Christmas tree, all spruces lose their needles when the tree dries out, so they can be very messy by the time it's time to compost the tree. The needles compared to fir trees, which don't lose their needles when dry, are also much sharper and not as nice to handle, and can be quite dangerous to small children with sensitive skin and to animals (compare the photos of the needles above to the needles in my blog post about the white fir HERE). Spruces also don't smell as wonderful as fir trees do; the typical "Christmas smell" that I think of when I think of Christmas is cinnamon, apples, the smell of fir trees, and a roasting turkey. Yum!

This variety of spruce tree is actually quite misleading when it comes to the "typical" form of spruces. It actually looks absolutely nothing like a typical Colorado spruce, and actually much more like a black spruce (which you can read all about HERE). Black spruces, except when young, have this type of characteristic shape; very dense branch growth towards the top of the tree that point almost straight outwards but with very short branches, then the longer branches towards the bottom of the tree are much longer, droop downwards, and are much more sparse compared to the top of the tree. The Colorado spruce, on the other hand, should be shaped almost like a pyramid with very dense branches throughout the length of the tree, and branches pointing nearly straight outwards. The Hoopsii spruce, a variety of the Colorado spruce, was selected by humans to have that drooping, very narrow growth habit.

As for the uses of the Colorado spruce, it is rarely used in the lumber or paper and pulp industry unless it is found growing in a stand of trees intended for pulping. It grows incredibly slowly and adds very little girth with each growing season, so is not very useful for lumber. The Navajo use the bark from the Colorado spruce as a medicinal item; it is steeped like a tea with other herbs to treat various medical conditions. The Colorado spruce is also the state tree of Utah and (of course) Colorado.

The Colorado Christmas Tree

Species name: Abies concolor

Common name: white fir, Colorado fir

Location: Ontario

As you can probably imagine from the common name, this tree is native to western North America in alpine regions in and around Colorado. While this tree survives well in eastern North America as an ornamental tree, it doesn't make seeds willingly (while cones can be quite prolific, depending on the environmental conditions). In its native range, it hybridizes readily with the grand fir.

Throughout much of North America, this tree is a very popular ornamental tree due to the coloration of the needles. It's not nearly as big of a contrast from regular green trees as the blue spruce is, but it is still quite the contrast nonetheless. There are huge stands of white fir trees of all roughly the same age, which may look strange to visitors to Canada and the United States. If you drive past the stand often, you'll notice the trees never get very large before the entire stand is cut down. This might make you think they're being used for some sort of commercial or industrial purpose and you'd be correct: Christmas trees! The white fir (sometimes sold as the concolor fir) is the single most popular tree to use as a Christmas tree due to the softness of the needles, the colour of the needles, and the fact that the needles stay firmly attached to the tree even after they start drying out (this cannot be said for all fir trees, and certainly can't be said for spruce trees). It also has a great smell when the tree starts to dry out!

Other than commercial value of the white fir as Christmas trees, it has very few other commercial uses. It is sometimes used as a pulp and paper tree, but only when its growing where it isn't wanted in a stand of other trees; the lumber is very soft and very knotty. The tree also is not self-pruning like many other coniferous trees, and retains its lower branches when mature (even though they have long since lost their needles). This is of great concern for "lumber farms," and National and Provincial Park staff; the bottom branches of the tree act as a sort of fire ladder, spreading forest fires very quickly through stands of trees.

This species of conifer tree is important in forests for reasons other than just fire hazards and as the odd pulp source; they are also the host for fir mistletoe, a parasitic plant that grows off of the carbon sources produced by the host plant. It doesn't produce any of its own food, and doesn't ever produce roots that root the shrub to the ground. Instead it completely relies on the fir tree for shelter, food, protection, and water. The mistletoe likely doesn't ever weaken the tree to the point where it will kill it, but when a tree is weakened for any reason it is more likely to be invaded by insect pests or infectious fungi. Mistletoe can indirectly lead to stand-wide forest death.