Tree of the Week: Spruce Pine (Pinus glabra)

Not every specimen in the Centenary arboretum has a well-documented history. As we have noted in the past, some trees predate its existence; in these cases we rely on archival photographs and tree morphology to make estimates regarding age. Other trees are volunteers which weren't noticed until they had already become established, obscuring not only their source but their true age. In a minority of cases, someone (Dr. Leuck, a student worker, or myself, the current arboretum curator) has planted a tree without recording full information on it.

This week we cover a tree falling into the last category, a spruce pine (Pinus glabra). The arboretum has had four in its history, of which three remain. The first was purchased from Woodlanders nursery and survived from 1989 to 1999, when it was killed by beetles. Two more spruce pines were purchased from Coyote Creek nursery and planted by the Student Union Building in 1997, where they remain to this day. The fourth specimen, and the third living one, was planted in 2003, by Dr. Leuck, near the southwest corner of Mickle Hall. We don't know where it came from or how old it was at the time of planting.

Spruce pines are a relatively restricted species in terms of native area, which runs in a belt (about a hundred miles wide and seven hundred miles long) from south Louisiana to Georgia and South Carolina on the Atlantic coast. This tree would be an unlikely find in North Louisiana, although it is definitely part of the Southeastern Woodlands. Below, we'll take a look at this specimen and some of its characteristics.

Our tree of the week grows at the top of a slope, in front of the Ratcliff Gazebo, with Mickle Hall not too far away. The two photos above are of the same tree pictured 9 years apart. This tree has grown quite a bit since the blog started! Today, at eye level, we see the thick, straight trunk, with no lower branches. The green needles are still within arms reach, but you need to stretch upward to get to them. The photo from 2012 shows a handsome pyramidal form that we cannot appreciate today, due to the size of the tree and its competition within the landscape.

 

We cut a small branch for inspection, finding it to be incredibly aromatic. The air was immediately filled with a Christmas-like fragrance. These branches would make a fine Christmas wreath, especially since the cones are so firmly attached, further ornamenting the branch.

Needles are paired (two-needle bundles) and are short, measuring approximately 3 inches in length.

This tree is flush with numerous small cones. You won't find any on the ground. They are all firmly attached to the tree.

Surface roots are numerous around this spruce pine and make mowing difficult. Is this common for the species? Or is this the result of growing at the top of a slope? And why are they weeping?

 

You can find more pictures of this specimen on a blog post from 2012, found here.

For more information about this species, please consult the following online resources:

US Forest Service: Pinus Glabra

University of Florida: Pinus Glabra