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 rays of the western firs frequently contain colored material that makes them stand out more on edge-
grain surfaces.
3.2.1.4 Southern Yellow Pine. The southern yellow pine group (Pinus sp.) is
composed of ten different species. Four species, loblolly (Pinus taeda), shortleaf (P. enchinata),
longleaf (P. palustris), and slash (P. elliottii), make up 90 percent of the total timber inventory.
Other species include spruce pine (P. glabra), Virginia pine (P. virginiana), sand pine (P. clausa),
pitch pine (P. rigida), pond pine (P. serotina) and table mountain pine (P. pungens). The wood of
all southern pines is similar and individual species cannot be reliably separated. This group ranges
throughout the southeast from eastern Texas to the east coast and northward to Missouri and east to
southern Indiana, Pennsylvania, Maryland and Delaware.
Southern yellow pine is a moderately heavy wood with a typical weight ranging from 36 to 44
pounds per cubic foot. The average specific gravity for the four major species is 0.55. Typically,
the wood is moderately hard, moderately strong, stiff, and moderately shock resistant. The
heartwood, which constitutes only a very small portion of the current timber supply, is moderately
decay resistant.
The heartwood color ranges from shades of yellow and orange to reddish-brown or light brown.
The transition from earlywood to latewood is abrupt, with the annual rings prominent on all sur-
faces. Resin canals are large and abundant and are easily found in all growth increments. Consider-
able variation in ring width due to growth conditions occurs; the faster growth wood being less
strong.
3.2.1.5 Miscellaneous Yellow Pines. Several species of yellow pine either grow
or have been planted in Central and South America, Australia and New Zealand. These species in-
clude radiata or Monterey Pine (Pinus radiata), Caribbean Pine (Pinus Caribaea) and others. The
woods of these species cannot be separated from the southern yellow pines produced in the United
States. Some of the trees in this group, depending on geographic location and other factors, have a
fast growth rate. A fast growth rate will reduce the strength properties and some caution should be
exercised in accepting this wood when it is not graded for strength.
ways, have broad deciduous leaves as described in Chapter 2. These leaves change color and drop
to the ground each fall. Figure 3-2 shows four of the five species or species groups discussed below.
3.2.2.1 Red Oak. The red oak group (Quercus sp.) includes northern red oak
(Quercus rubra), black oak (Q. velutina), scarlet oak (Q. coccinea), schumard oak (Q. shumardii),
pin oak (Q. palustris), Nuttall oak (Q. nuttallii), southern red oak (Q. falcata), water oak (Q.
nigra), laurel oak (Q. laurifolia), and willow oak (Q. phellos). Red oaks range east of the Great
Plains except for a narrow coastal strip along the Gulf of Mexico and in Florida.
Red oak averages 44 pounds per cubic foot and the average specific gravity is 0.63. The wood is
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