Pinus rigida

Miller (1768)

Common names

Pitch pine; pin rigide [French]; リギダマツ [Japanese].

Taxonomic notes

Type not designated. Syn. Pinus taeda var. rigida (Mill.) Aiton. Some infraspecific taxa have been described, but none are currently recognized. This species belongs to subgenus Pinus, subsection Australes, clade Taeda (Cruz-Nicolás et al. 2024), which is comprised of species all found in the SE US, but occupying different habitats. Phylogenetic relationships between the 6 species in the clade remain unclear. Nuclear DNA allies southern specimens of P. rigida to P. taeda and northern ones to P. serotina (Cruz-Nicolás et al. 2024). The transcriptome places it sister to P. serotina (Jin et al. 2021), while plastid markers place it sister to P. pungens (Hernández-León et al. 2013).

P. rigida is known to hybridize naturally with P. echinata (Kral 1993). The two species introgress over a wide area in eastern Kentucky (and perhaps elsewhere where sympatric), 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

Monoecious evergreen trees to 31 m tall and 90 cm dbh, usually with a single straight or crooked trunk, commonly bearing adventitious sprouts between some of the bark plates, poorly self-pruning; crown rounded or irregular, made up of arching, spreading to ascending branches. Bark red-brown, deeply and irregularly furrowed with long, irregularly rectangular, flat, scaly ridges; resin pockets absent. Twigs 5-10 mm thick, yellowish-green soon turning reddish brown, rough with pulvini after leaves have fallen. Buds ovoid to ovoid-cylindric, red-brown, ca. 10-15 mm long, resinous; scale margins fringed, apex cuspidate. Leaves 3(-5) per fascicle, spreading to ascending, persisting 2-3 years, 5-10(-15) cm × 1-1.5(-2) mm, straight, twisted, deep to pale yellow-green, all surfaces with fine stomatal lines, margins serrulate, apex abruptly subulate-acuminate; sheath 9-12 mm, persistent. Pollen cones cylindric, ca. 20 mm, yellow. Seed cones solitary or in whorls of 2-5, maturing in 2 years, shedding seeds soon thereafter or variously serotinous and long-persistent, often clustered, symmetric, conic to ovoid before opening, broad-ovoid with flat or slightly convex base when open, 3-9 cm long, creamy brown to light red-brown, sessile to short-stalked, base truncate, scales firm, with dark red-brown border on adaxial surface distally; apophyses slightly raised, rhombic, with strong transverse keels; umbo central, low-triangular, with slender, downcurved prickle. Seeds broadly obliquely obovoid-deltoid; body 4-5(-6) mm, dark brown, mottled darker, or near black; wing 15-20 mm. 2n=24 (Kral 1993, Farjon 2010). See García Esteban et al. (2004) for a detailed characterization of the wood anatomy.

Also see the Key to the Pines of the Southeastern United States.

The only other pine in the SE US to bear adventitious sprouts is P. serotina, which has longer, pliable needles.

Distribution and Ecology

Canada: Ontario and Québec; S through USA: Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Delaware, Pennsylvania, Maryland, Ohio, Virginia, West Virginia, Kentucky, Tennessee, North Carolina, South Carolina and Georgia. Upland or lowland sites on sterile, dry to boggy soils; at 0-1400 m elevation (Kral 1993). See also Thompson et al. (1999). Hardy to Zone 4 (cold hardiness limit between -34.3°C and -28.9°C) (Bannister and Neuner 2001).

Distribution data from USGS (1999).

It is fire successional, sprouts adventitiously, and is frequently shrubby in the northern part of its range (Kral 1993).

Remarkable Specimens

The largest on record is diameter 129 cm, height 29 m, crown spread 13 m, located in Newberry, New Hampshire (American Forests 1996). The tallest known one is 44.6 m tall, 71 cm DBH, and grows near the West Fork Chattooga River in Georgia (Riddle 2016). Another very tall tree in Great Smoky Mountains National Park is 41.27 m tall (Rucker 2003). The oldest known tree was 398 years old, crossdated, when it was sampled in 2013 in Minnewaska Lake State Park, New York. It was found and sampled by C. McIntire, K. Pendergrass, and the NADEF 2013 Advanced DendroClimatology Group (Pederson 2025). Another very old tree was found growing at Mohonk Lake, New York by Ed Cook in 1973. He collected specimen 420411, presumably from a live tree, and it had 351 rings. This is a crossdated age (NCDC 2006).

Ethnobotany

Commercially, this is a low-value timber species (Kral 1993).

Observations

Near the southern end of the species' 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 rigida means "stiff", and refers to the needles.

Citations

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

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.

Hernández-León, S., D. S. Gernandt, J. A. Pérez de la Rosa, and L. Jardón-Barbolla. 2013. Phylogenetic relationships and species delimitation in Pinus section Trifoliae inferred from plastid DNA. PLoS ONE 8:e70501.

Jin, W.-T., D. S. Gernandt, C. Wehenkel, X.-M. Xia, X.-X. Wei, and X.-Q. Wang. 2021. Phylogenomic and ecological analyses reveal the spatiotemporal evolution of global pines. Proceedings of the National Academy of Sciences 118:e2022302118.

Miller, P. 1768. The Gardener's Dictionary, ed. 8. London. 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, Neil. 2025. Eastern OLDLIST. https://dendro.cnre.vt.edu/olds/detail.cfm?genus=Pinus&species=rigida, accessed 2025.03.01.

Riddle, Jess. 2016. West Fork Chattooga River Pines. http://www.ents-bbs.org/viewtopic.php?f=73&t=7533, accessed 2017.11.04.

Sargent, Charles Sprague. 1947. The Silva of North America, Vol.XI, Coniferae. New York: Peter Smith. Plate DLXXIX. Available: Biodiversity Heritage Library, accessed 2021.12.19.

See also

Elwes and Henry 1906-1913 at the Biodiversity Heritage Library. This series of volumes, privately printed, provides some of the most engaging descriptions of conifers ever published. Although they only treat species cultivated in the U.K. and Ireland, and the taxonomy is a bit dated, still these accounts are thorough, treating such topics as species description, range, varieties, exceptionally old or tall specimens, remarkable trees, and cultivation. Despite being over a century old, they are generally accurate, and are illustrated with some remarkable photographs and lithographs.

Gucker, Corey. 2007. Early postfire response of southern Appalachian Table Mountain-pitch pine stands to prescribed fires in North Carolina and Virginia. http://www.fs.fed.us/database/feis/research_project_summaries/Welch00/all.html, accessed 2009.03.28.

Knebel ond Wentworth (2007).

Pinchot, Gifford. 1897. Three New Jersey pines. Garden and Forest 10:192. Available at the Biodiversity Heritage Library, accessed 2024.12.24. Observations on sprouting of fire-killed pines.

The FEIS database.