How ling are the needles?

Shortleaf: 7-11cm
Loblolly: 12-22cm

Now tell me all their needles are 11-12cm long ;-)

Resin

Ooops! That should of course read "How long ..."

Generally speaking 2 needles are shortleaf and 3 needles are loblolly, but nearly every account I've read lists shortleaf as sometimes having 3 needles and loblolly as sometimes having 2 needles.
Per Resin's note above, needle length is the most reliable. And of course sometimes in the wild they hybridize.

They really don't look that much alike. The color of the needles is different and they are much much shorter on the shortleaf pines.

John, what type of growth have you had in your pines? My loblollies have grown quite a bit faster than the shortleafs. I planted the shortleafs in February '06 and the loblollies in March of this year. Also planted white pines in February '06 and growing fast, but deer are mangling a lot of them.

Typically loblolly has 3 needles while shortleaf has 2 needles. At least in my trees the shortleaf needles are a more emerald green color and the loblollies are darker.

Eric

shortleaf pine... only has a short leaf for a southern pine... and thats not all that short at all.

Loblolly Pine (Pinus taeda)
Needles are 5.5 to 9 inches long
Needles are usualy in groups of 3

Shortleaf Pine (Pinus echinata)
Needles are 3 to 5 inches long
Most needles are in groups of 2 but can have some rare 3 needle groups mixed in.

It's easy to tell the difference because if most or all needles are in groups 3 then it's a Loblolly Pine, and if most or all needles are in groups of 2 then it's a Shortleaf Pine. If you want to be even more sure just use the needle length measurements above.

I'd be a little cautious about relying too much on needle number, it is more variable in young plants; vigorous young specimens of normally 2-needle pines often have many in 3s particularly on the lead shoot. I'd not be surprised if the lead shoot of a healthy young P. echinata had mostly 3s.

Resin

I don't know about shortleaf pines, but, unlike the longleaf pines on my property, loblolly pine needles are very aromatic. The only problem with the smell test might be that very young loblollies don't smell as good as mature ones, I don't know - I'll go outside and find some seedlings and see.
Sherry

I have some young Slash pines that I started from seed. In the beginning they had mostly three short needles and I thought I mistakenly had Loblolly, but now most of needles are longer and only two per fascicle. They do look different when juvenile.

Needle length might be a better in differentiating but Loblolly seedlings can have some needles that are around 4 inches long (10cm) when they are young so it's not always perfect. Differentiating between Shortleaf and Loblolly seedlings with needle groups can be pretty good because on Loblolly seedling 99 to 100% of the needles have 3 groups. Where as you won't see a Shortleaf Pine with 99 to 100% of the needles with groups of 3, they might could possibly have around 10 to 20% of them with 3 but no where near 99 to 100%. That's why it's good to look at several or more needles of a seedling, not just a couple when counting the number of needles in a group plus measuring the needles also.

We have both Shortleaf and Loblolly pines at our place with many Loblolly seedlings. I've looked at many Loblolly seedlings and their hundreds of needles and all I've seen are groups of 3.

ATH, in my observations it is far more common to find sheaths of 3 needles on a slash pine than to find sheaths of 2 on a loblolly.

I checked some loblolly seedlings and young pines, and they don't have the wonderful smell the needles on the mature trees have. I'd say 95% of the needles are in bundles of three.
Sherry

Hi John: I imagine it is difficult to identify some of your seedlings at this stage.

The Virginia Department of Forestry published "Native Trees of Virginia" (124 pages) this summer. This publication includes tree identification info and and a key to common native trees. I think it would be useful for almost anyone since these trees are common to many areas of the country.

It includes keys to common native trees, then a cross reference to a page about that tree. Here is what it says about shortleaf and loblolly pines:

6 a. Needles 6 to 9 inches, cones 3 to 6 inches long  Loblolly Pine, pg. 21.
b. Needles 8 to 18 inches, cones 6 to 10 inches long  Longleaf Pine, pg. 22.

Page 21: "Loblolly pine: Needles: 6 to 9 inches long, pale green, slender and stiff, in bundles of three"

8 a. Needles 3 to 5 inches, dark yellow green, cones 1½ to 2½ inches long  Shortleaf Pine, pg. 20.

Page 20: "Shortleaf pine: Needles: 3 to 5 inches, slender, flexible, dark green, in clusters of 2 or 3."

This book has been helpful in improving my limited tree identification skills. I downloaded it for free but cannot find a download link now. You can purchase it for $1.00 from the Virginia Dept of Forestry (link below).

Here is a link that might be useful: Native Trees of Virginia

The needles are about 4-5" long - plus or minus. Remember the tree is only 2-3 yrs old, so the needle length may not be a good indicator.

I'd say 90% of the needles are in groups of 3 - 10% in groups of 2.

scotjute- You say that nearly every account you've read lists loblolly as sometimes having 2 needles. Definately not saying you are wrong, but I haven't found that note in my books. I tried to find something along those lines on the web, but couldn't.

Resin- You stated needle clusters may vary when trees are young. That may be the reason why loblollies have more groups of 2 when young?

It sounds like if the majority of needle clusters are in groups of 3, it's a loblolly rather than shorleaf.

Thanks everyone.

"Resin- You stated needle clusters may vary when trees are young. That may be the reason why loblollies have more groups of 2 when young?"

It's more the other way, that vigorous young seedlings have more needles than usual per fascicle, so a young Shortleaf could have most of its fascicles in threes.

I've never done needle counts on Shortleaf, but on other 2-needle pines (e.g. Scots Pine, Austrian Pine) it's normal to find quite a lot of 3s (and even occasional 4s and 5s) on young plants 2-10 years old, particularly on the leader.

Resin

Speaking of virginia, Pinus virginiana is another nice pine you might want to plant. If I could get my grubs on some I'd definitely use them. They are used as christmas trees and actually grown in areas of the southeast where other more common types of christmas trees wouldn't do too well.

My Loblolly x Pitch pine hybrid has a fair number of needles on the vigorous sprouts in clusters of 4 (the rest in threes).

Virginia & Table mountain pine saplings have some in threes, the rest twos.

More mature trees stick to their "usual" number.

johnstaci,
I stand corrected. Most of my usual sources were talking about Shortleaf Pine when referring to 2-3 needles per fascicle, only one mentioned Loblolly. Everything else did indeed say "3" for Loblolly.

Flora of North America - "Leaves 2--3 per fascicle, ascending to spreading, persisting 3 year ..." for Pinus taeda. Says same thing for leaves of shortleaf pine.

enature.com - "Needles: evergreen; 2 3/4-4 1/2" (7-11 cm) long, 2 or sometimes 3 in bundle; slender, flexible; dark blue-green" for Shortleaf pine. 3 for Loblolly.

Texas Native Trees - "Shortleaf pine's bluish-green needles are in bundles of 2 and 3 and are 2 to 5 inches long; its cones, 1 to 2 1/2 inches long...", once again, 3 for Loblolly. Checked 3 other sources which were either silent or stated 3 also.