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Bluejack Oak

The Quercus Incana is commonly known as Bluejack Oak, Cinnamon Oak, Sandjack Oak, as well as Upland Willow Oak

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Growing Regions

Bluejack oak occurs on the Atlantic and Gulf coastal plains from southeastern Virginia south to central Florida; west to Louisiana and eastern and central Texas; and north to southeastern Oklahoma and southwestern Arkansas [22].


General Information

The currently accepted scientific name for bluejack oak is Quercus incana Bartr. (Fagaceae) [22]. There are no accepted infrataxa. Bluejack oak forms hybrids with seven other oak species [22,40].

Bluejack oak typically occurs in longleaf pine (Pinus palustris)
communities [25,27,36,].  Bluejack oak and turkey oak (Quercus laevis)
grow to about half the height of the dominant longleaf pines,
maintaining a sparse middle canopy layer.  The herb layer is usually
dominated by wiregrass (Aristida stricta) [28].  There are three
distinguishable phases of the Florida sandhills (longleaf pine)
associations:  1) turkey oak (Quercus laevis), 2) bluejack oak or sand
post oak (Q. stellata var. margaretta), and 3) southern red oak (Quercus
falcata) [6,7,25,36].  In each of these associations, longleaf pine
occurs as scattered overstory individuals.  The turkey oak phase occurs
on the driest sites, with scattered bluejack oak and persimmon
(Diospyros virginiana).  The bluejack oak phase is more characteristic
of fine-textured, somewhat more fertile soils.  Live oaks (Quercus spp.)
are common in the overstory.  The herb layer is characterized by
wiregrass and pineywoods dropseed (Sporobolus junceus) [6].  In the
sandhills of the Big Thicket region of Texas, dominant oaks are bluejack
oak and post oak (Q. stellata); dominant pine species include longleaf
pine, shortleaf pine (P. echinata), and loblolly pine (P. taeda).  Pine
densities are low, herb cover is sparse, and there are many areas of
exposed sand [6].

In Texas, bluejack oak is found on the deep sands of Pineywoods, Gulf
prairies and marshes, and post oak savanna (Quercus stellata).  In post
oak savanna, associated tree species include blackjack oak (Quercus
marilandica), black hickory (Carya texana), mesquite (Prosopis spp.),
Texas live oak (Q. virginiana var. fusiformis), post oak, and sand post
oak.  Associated herb layer species include sand lovegrass (Eragrostis
trichodes) and threeawn (Aristida spp.).  In the northeast Pineywoods,
bluejack oak occurs in shortleaf pine-post oak-southern red oak and
longleaf pine-bluejack oak associations.  Flowering dogwood (Cornus
florida) is associated with bluejack oak on some sites [45].  Bluejack
oak shares dominance with blackjack oak and sand post oak on sites
downslope of the extremely dry ridge tops that are dominated by turkey
oak [6].

Bluejack oak is listed as a dominant, codominant, or indicator species in
the following publications:

Longleaf pine communities of the west Gulf Coastal Plain [4]
The vegetation of the Apalachicola National Forest: an ecological
  perspective [7] 
Natural communities of Florida's inland sand ridges [9] 
Landscape ecosystem classification for South Carolina [19] 
Forest vegetation of the Big Thicket, southeast Texas [23]
Eastern deciduous forest, Vol. 1 [41]

Much of the information presented here is attributed to:
Sullivan, Janet. 1994. Quercus incana. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available at USDA Forest Service.

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