spruce pine/sand pine id

[caveman]

I have the challenge of trying to explain to students how to distinguish spruce pine (Pinus glabra) cuttings from sand pine (Pinus clausa).  They will not be able to see the tree, just a limb cutting.  In the past, I have told them to look at the sample from five feet or so and if the needles appear soft and twisted then it is a spruce pine.  I am looking for a better method.  I do not have access to spruce pines in my area.  The first one the students will likely see is next week at their state forestry contest.
Thank you,
Caveman

[WDH]

Four things to look for:

The needles of spruce pine are a little flimsy and slightly twisted.  Stouter in sand pine, but this is a little subjective.

The bark of spruce pine looks like hardwood bark, not pine bark.  If the bark on the twig is smooth and looks like a hardwood, it is most likely spruce pine versus sand pine.  It will be a grayish green, not brown.  The bark on sand pine twigs looks like the bark on other pine twigs, brown and a little scaly. 

Looking at the cone, the contrast between the seed scale and the tip of the cone scale (the border in between) is dull.  In sand pine, the border between the seed scale and the cone scale tip is red-brown or purplish with a very noticeable contrast.  Kind of like that seen in virginia pine cones.  Look inside the cone scale and look at the contrast at the tip on the inside.  It will be very hard to see any color contrast in spruce pine.

The prickles on spruce pine cones are weak and are deciduous.  Sand pine cones have stout sharp prickles.

Looking at a tree, they look nothing alike.  Spruce pine has bark that is grey and looks like a hardwood.  The bark on the upper part of the stem is smooth.  It grows on wet sites.  Sand pine has the typical brown scaly pine bark and it grows on deep droughty sands.  However, I realize that your students will be IDing samples and will not see the trees in their natural environment.

If your students have access to sand pine twigs and cones, I would have them study them very carefully.  Especially the cones with the sharp stout prickles and the color contrast at the tip of the cone scale.  When they see the spruce pine twigs and cones, they should look a good bit different.

[caveman]

Thank you for the tips Danny.  I think I will go collect samples from several different locations of sand pine specimens.  Until the state contest, the only two needle pine they needed to learn is the sand pine.  Once we get the sand pine samples, we will sit down and closely study them while reading your descriptions.  The team should get to see a spruce pine sample Thursday evening.

A retired ag teacher friend of mine will be accompanying the team from Port Charlotte if his health allows (he has congestive heart failure and his propensity to smoke a lot, drink caffeinated beverages, hunt, train FFA teams and fish occasionally force him to rearrange his plans).  He will show up in Perry on Thursday with examples of every tree specimen that could possibly be on the test.  The cool thing is that he will allow students from other teams to look at his samples.  I spoke to him yesterday and thanked him for the lessons he has taught me over the years and told him I try to emulate him with regards to teaching and life in general.

We have Veterans' Day off next Tuesday but the team decided that they would like to spend the day practicing.  A few hours walking through the woods and another few hours going over the general knowledge, tools, pests and management problems should be a good way to spend the day.

WDH, one of these days I hope to get to attend your "dendrology class" that Raider Bill mentioned a few weeks ago.
Kyle
Caveman

[WDH]

The class is free  ;D.

[caveman]

WDH, at the beginning of forestry class today I pulled up the forum and projected your suggestions for differentiating spruce pine cuttings from those of sand pine.  After work today, I drove around and got four sand pine cuttings from three different sites and from trees of different ages and compared them.  We will spend some of tomorrow's practice time going over them. 

If I am going to continue doing this, I need to plant more of the trees that are hard for me to get at home and school. 
Thanks again,
Kyle

[WDH]

Let us know how the competition works out.

IDing a tree is best if you have the whole tree to examine.  Having just a branch or needles or just leaves can be very challenging. 

[caveman]

We are heading to Perry almost a whole day prior to the contest so that we can get some practice, look at whole trees, growing habits, crush leaves, peel stems, taste stuff and generally exhaust every opportunity to reduce identification errors.  We will still need to work on compass and pacing and timber estimation quite a bit.

The compass and pacing practicum rotates yearly with USGS map interpretation.  I prefer maps to pacing.  We should have results by lunch time Friday and then we have a four hour drive home.  The team that wins will go to the national event next October in Louisville.  There will be some very well prepared teams.

[caveman]

Looking at the cone, the contrast between the seed scale and the tip of the cone scale (the border in between) is dull.  In sand pine, the border between the seed scale and the cone scale tip is red-brown or purplish with a very noticeable contrast.
WDH-Is this line on the sand pine cone, in the picture that hopefully appears below, what you are explaining?  If so, I hope they give the students opened cones to look at.  Thanks, Kyle

 

[WDH]

Exactly.  Look at the cone scale.  You can see the where the seeds were and the seed wings.  Two of them per each cone scale.  The border where the seed wing was and the tip of the cone scale is a deep purple in your pic.  In spruce pine, this border will be a dull brown, hardly any contrast in color at all. 

Nice pic. 

[caveman]

Thank you for clarifying.  We started the morning looking at this sample and three other cuttings of sand pines while reading a copy of your post. When I saw the distinct color change like you described  it began to click.  Your knowledge amazes me.  I did not see this on the VT fact sheet.
Kyle
 

[davidlarson]

I live in Spruce Pine, NC, a mountain mining town in western NC with a population of 2333 when my wife and I are home.  Around here the local mountain folks call rhododendron laurel, and mountain laurel is called ivy.  What most people call Carolina hemlock, the locals call spruce pine.

[WDH]

Cones can be very distinctive.  You can tell longleaf, loblolly, slash, and shortleaf just from a cone.  Most of the other southern yellow pines, too, like pitch, pond, table mountain, and virginia.  Spruce pine and shortleaf pine have very similar cones, but I believe that the stoutness of the prickle might help separate them.

With spruce pine, by far the easiest way to ID it is that unusual gray hardwood bark on a pine.  SOme people say that the bark looks like spruce bark, but we do not have any spruce trees down here to compare it to, but there is a world of hardwood.