Appendices & Glossary - Botanical Research Institute of Texas

1330 APPENDIX TWENTY-ONE/COMMERCIALLY IMPORTANT TIMBER TREES OF EAST TEXAS
QUERCUS NIGRA L. WATER OAK
(FAGACEAE, BEECH OR OAK FAMILY)
Other Common Names: POSSUM OAK, SPOTTED OAK, DUCK OAK, PUNK OAK
Form and Size: medium to tall tree to 30(–44.5) m; trunk straight, 0.3–1 m in diameter; crown rounded or cone-shaped.
Leaves: deciduous or tardily so, simple, alternate, the blades 3–12(–16) cm long, 1.5–6(–7) cm wide, dull green and smooth
above, paler below, turning yellow to brownish in autumn, with tufts of hairs in the main junctions of veins on the
lower surface, much broader apically than basally and definitely club-shaped but variable, unlobed and with one apical
bristle tip or shallowly 3(–5)-lobed (occasionally pinnately lobed, particularly on sprouts) and the lobes with
bristle tips; petioles stout, flattened, 2–9 mm long.
Buds: 3–6.5 mm long (terminal), dark reddish-brown, the scales hairy.
Flowers: unisexual, male and female flowers occurring separately on the same tree (plants monoecious), individually tiny
and inconspicuous; male flowers numerous on slender dangling catkins 4–7.5 cm long; female flowers in few-flowered,
short-stalked clusters in leaf axils.
Fruits: acorns usually solitary, maturing in two seasons; cup covering 1/4 of nut or less; nut broadly ovoid, 9.5–14 mm
long, 9.5–14.5 mm wide.
Bark: very dark gray to grayish black, smooth and thin, later developing rough, wide scaly ridges.
Wood: similar to Q. falcata, sapwood and heartwood reddish-brown, heavy, strong; grain coarse.
Habitat: typically on moist alluvial and lowland sites such as stream bottom woods, but it can occur on a wide variety of
soil types and in varying habitats including moist uplands.
Range: Pineywoods, northern Gulf Prairies and Marshes, Post Oak Savannah, and Blackland Prairie west to western margin
of East Texas; mainly southeastern U.S. from NJ south to FL w to OK and TX.
Principal Uses: mostly general construction, boxes, crates, fuel. The wood is inferior to that of other red oaks, but it is often
sold as “red oak.”
Historical Uses: the wood is not as high quality as that of a number of other oak species; consequently it was not extensively
used when other higher quality woods were readily available.
Other Significant Information: this rapidly growing species is often planted as a street or shade tree. It is also often abundant
as second growth in appropriate habitats on cutover lands. As is the case with many oaks, hybridization is well
known. Quercus nigra hybridizes with almost every other species in section Lobatae (red or black oak group), including Q.
laurifolia (LAUREL OAK), Q. marilandica (BLACKJACK OAK), Q. phellos (WILLOW OAK), Q. shumardii (SHUMARD’S OAK), and
Q. velutina (BLACK OAK). Many interesting hybrids can be observed, and it is often difficult to distinguish between species
in this complex in the field.
Recognition in the Field: leaves simple, alternate, much broader apically than basally, definitely club-shaped, and unlobed
or shallowly 3(–5)-lobed apically; twigs and petioles glabrous or nearly so; fruit an acorn with cup covering 1/4 of nut
or less.