Pinus echinata (shortleaf pine) description

Pinus echinata

Miller 1768

Common names

Shortleaf pine, shortstraw pine, southern yellow pine; エキナタマツ [Japanese].

Taxonomic notes

This species belongs to subgenus Pinus, subsection Australes Loudon, clade Taeda (Cruz-Nicolás et al. 2024). This clade is comprised of species found in the SE US, and most of the pines that co-occur with this species in mixed stands (including P. elliottii, P. glabra, P. palustris, P. serotina, and P. taeda) are in the same subsection. P. echinata hybridizes naturally with P. taeda; the hybrids tend to closely resemble P. echinata rather than P. taeda (Edwards-Burke et al. 1997). In eastern Kentucky (and perhaps elsewhere, where sympatric), P. echinata introgresses with Pinus rigida, producing trees with very small, P. rigida-shaped seed cones, and larger seed cones that are intermediate between the normal shape for each species (R. Clark email 2009.12.15).

Description

"Trees to 40 m; trunk to 1.2 m diam., straight; crown rounded to conic. Bark red-brown, scaly-plated, plates with evident resin pockets. Branches spreading-ascending; 2-year-old branchlets slender (ca. 5 mm or less), greenish brown to red-brown, often glaucous, aging red-brown to gray, roughened and cracking below leafy portion. Buds ovoid to cylindric, red-brown, 0.5-0.7(1) cm, resinous. Leaves 2(3) per fascicle, spreading-ascending, persistent 3-5 years, (5)7-11(13) cm x ca. 1 mm, straight, slightly twisted, gray- to yellow-green, all surfaces with fine stomatal lines, margins finely serrulate, apex abruptly acute; sheath 0.5-1(1.5) cm, base persistent. Pollen cones cylindric, 15-20 mm, yellow- to pale purple-green. Seed cones maturing in 2 years, semipersistent, solitary or clustered, spreading, symmetric, lanceoloid or narrowly ovoid before opening, ovoid-conic when open, 4-6(7) cm, red-brown, aging gray, nearly sessile or on stalks to 1cm, scales lacking contrasting dark border on adaxial surfaces distally; umbo central, with elongate to short, stout, sharp prickle. Seeds ellipsoid; body ca. 6 mm, gray to nearly black; wing 12-16 mm. 2n=24" (Kral 1993). See García Esteban et al. (2004) for a detailed characterization of the wood anatomy.

There are few similar species. The short needles and small cones (often presented in very large cone crops that are retained on the tree for several years) are quite distinctive.

Distribution and Ecology

USA: New York, Pennsylvania, Ohio, Illinois, Arkansas, Missouri, Kentucky, Tennessee, West Virginia, Maryland, Delaware, Virginia, North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, Oklahoma and Texas. Typically in uplands, relatively dry forests at 200 to 610 m elevation; commonly in mixed stands with Pinus taeda (Kral 1993). See also Thompson et al. (1999). Hardy to Zone 6 (cold hardiness limit between -23.2°C and -17.8°C) (Bannister and Neuner 2001).

Distribution data from USGS (1999).

Remarkable Specimens

The current largest tree on record is 124 cm dbh, 32.9 m tall, crown spread 23.8 m, last measured in 2018, located in Smith County, Texas (American Forests 2023). An earlier record tree was 108 cm dbh, height 42 m, crown spread 23 m, located in Myrtle, Mississippi (American Forests 1996). The tallest known one is in the Abrams Creek watershed in Tennessee; it is 45.5 m tall (Blozan 2011). Another tree, nearby in Great Smoky Mountains National Park, was 43.16 m tall in 2004 (Robert Van Pelt e-mail 2004.02.17).

In 2007, the field class of the Dendroecological Fieldweek established a crossdated age of 324 years for tree GMX307, in the Great Smoky Mountains National Park, Tennessee (Pederson 2008). Tree LAW38 had a crossdated age of 314 years, and was alive when collected in 1980 at Lake Winona Natural Area, Arkansas by D. Stahle and G. Hawks (NCDC 2006). It would be interesting to know if this tree survives.

Ethnobotany

Highly valued for timber and pulpwood (Kral 1993).

Observations

I have seen it in the North Carolina sandhills, such as at the Weymouth Woods Sandhills Nature Preserve, but it it reportedly quite common in much of its range. Some exceptionally large and tall trees occur along the Abrams Creek Trail in Great Smokies National Park (Will Blozan pers. comm. 2024.03.08).

Remarks

The epithet echinata means "spiny", but it is not clear what Miller was referring to; perhaps the mature seed cones.

Citations

American Forests 1996. The 1996-1997 National Register of Big Trees. Washington, DC: American Forests.

American Forests 2023. 2021 National Register of Champion Trees, accessed 2023.02.22.

Blozan, Will. 2011.05.14. Abrams Creek, TN- new shortleaf pine and paw-paw record. www.ents-bbs.org/viewtopic.php?f=74&t=2487, accessed 2011.05.15.

Cruz-Nicolás, Jorge, Juan Pablo Jaramillo-Correa, and David S. Gernandt. 2024. Stochastic processes and changes in evolutionary rate are associated with diversification in a lineage of tropical hard pines (Pinus). Molecular Phylogenetics and Evolution 192:108011, https://doi.org/10.1016/j.ympev.2024.108011.

Edwards-Burke, M. A., J. L. Hamrick, and R. A. Price. 1997. Frequency and direction of hybridization in sympatric populations of Pinus taeda and P. echinata (Pinaceae). American Journal of Botany 84(8):879-886.

Miller, P. 1768. The Gardener's Dictionary, ed. 8. London. Pinus no. 12. Available: botanicus.org/title/b12066618, accessed 2011.05.20.

[NCDC 2006] Data accessed at the National Climatic Data Center World Data Center for Paleoclimatology Tree-Ring Data Search page. http://hurricane.ncdc.noaa.gov/pls/paleo/fm_createpages.treering, accessed 2006.09.08, now defunct.

Pederson, N. 2008. Eastern OlDLIST: A database of maximum tree ages for Eastern North America. http://people.eku.edu/pedersonn/oldlisteast/, accessed 2008.12.07, now defunct.