Pinus glabra

Walter 1788

Spruce pine, cedar pine, Walter pine.

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.

Description

Trees up to 30 m tall and 100 cm dbh. Trunk can be straight, but is often bent and twisted on trees that have regenerated beneath a canopy. Crown pyramidal to rounded. Bark on mature trees gray, fissured and cross-checked into elongate, irregular, scaly plates, lacking resin pockets; it resembles red oak bark, and is unlike any other pine in the region. On younger trees and branches, the bark is smooth and gray. Branches whorled, spreading to ascending; twigs slender, purple-red to red-brown, occasionally glaucous, aging gray, smooth. Buds ovoid to ovoid-cylindric, red-brown, ca. 0.5-1 cm, slightly resinous; scale margins finely fringed. Leaves 2 per fascicle, spreading to ascending, persisting 2-3 years, 4-8(10) cm × 0.7-1.2 mm, straight, slightly twisted, dark green, stomata in lines on all surfaces, margins finely serrulate, apex acute; fascicle sheath 0.5-1 cm, base persistent. Pollen cones long cylindric, 10-15 mm, purple-brown. Seed cones maturing in 2 years, shedding seeds soon after, persisting a year or more, spreading to recurved, nearly symmetric, long ovoid before opening, ovoid-cylindric when open, 3.5-7 cm, red-brown, aging gray, on peduncles 0.1-1 cm long. Cone scales lack contrasting border on adaxial surfaces (as in P. echinata); apophyses slightly thickened and raised; umbo central, depressed, unarmed or with small, curved, weak, deciduous, short-incurved prickle. Seeds deltoid-obovoid; body ca. 6 mm, brown, mottled darker; wing to ca. 12 mm. 2n=24 (Kral 1993, Mark Brian email 2006.12.31).

Similar species: Mature, open-grown individuals have a very similar form to P. strobus. Its shoots and leaves resemble P. echinata but cones are less prickly and leaves a deeper green (Kral 1993).

Distribution and Ecology

USA: South Carolina, Georgia, Florida, Alabama, Mississippi & Louisiana on sandy alluvium and mesic woodland in the Atlantic and Gulf coastal plains, at 0-150 m elevation (Kral 1993). Hardy to Zone 8 (cold hardiness limit between -12.1°C and -6.7°C) (Bannister and Neuner 2001). See also Thompson et al. (1999).

Distribution data from USGS (1999).

This pine is relatively shade tolerant, often growing in hardwood forests and even regenerating beneath a hardwood canopy (Kral 1993, Mark Brian email 2006.12.31).

Remarkable Specimens

A tree near Alachua, Florida; 110 cm dbh, 35.7 m tall, with a 15.5 m crown spread, when measured in 2016 (American Forests 2021). This is also the tallest tree of record. A previous champion near Norwood, Louisiana was 129 cm DBH and 34.14 m tall (American Forests 2000); since this was a larger tree, it has presumably died. The height record is matched by a tree in Moody Tract Natural Area, Georgia; it is 35.63 m tall (Rucker 2003).

Ethnobotany

Used for its lumber. Due to radically different drying rates, spruce pine cannot be intermixed with other southern pine species in lumber manufacturing. It can be made into lumber, but it must be dried separately. It is often used for large timbers and beams (Mark Brian email 2006.12.31).

Observations

Remarks

You will often see eastern turkey droppings on the ground under spruce pines. They are heavily utilized for winter roosting by turkeys, since they are often the only cover in the bottomlands in the winter (Mark Brian email 2006.12.31).

Citations

American Forests 2000. The National Register of Big Trees 2000. Washington, DC: American Forests.

American Forests 2021. 2021 National Register of Champion 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.

Walter, T. 1788. Flora Caroliniana. London: J. Fraser. p. 237. Available: botanicus.org/title/b12073714, accessed 2011.05.20.

See also

The FEIS database.