13. Quercus texana Buckley (Nuttall’s oak)
Quercus nuttallii E.J. Palmer
Pl. 415 a, b;
Map 1851
Plants trees to
25 m tall. Bark medium to dark gray, divided into persistent ridges, the inner
bark pinkish. Twigs 1.5–3.0 mm wide, dark brown, glabrous. Buds 3.5–5.0 mm
long, brown or grayish brown, the scales glabrous or minutely pubescent, also
hairy along the margins. Petioles 20–48 mm long. Leaf blade 9–19 cm long, 7–18
cm wide, obtuse or tapered at the base, divided 70–90% of the width, the lobes
2 or 3(4) per side, evenly spaced or the lowest closer together, the second
pair from the base the largest; well-developed lobes 11–26(–34) mm wide, oblong
or triangular, seldom much broadened outward, obtuse to slenderly tapered
apically, often with a few teeth on each margin and sometimes a secondary lobe
on the lower margin, each with 1–5 bristles 2–6 mm long (the whole blade with
13–30 marginal bristles), the strongest secondary veins reaching the margin at
the tips of the lobes and ending in bristles, others reaching toward sinuses
and turning aside before reaching the margin; the upper surface dull or rather
shiny, glabrous, the undersurface green, glabrous, smooth to the touch, the
vein axils with prominent tufts of 9–19-rayed, stalked hairs. Acorn cups 8–10 mm
long, 16–20 mm wide, covering 20–50% of the nut, bowl-shaped from a prolonged
base, the inner surface regularly dimpled, the central portion hairy, the outer
surface with the scales thin and plane, pubescent. Nuts 14–23 mm long, 13–17 mm
wide, ovoid, without concentric grooves around the tip. April–May.
Uncommon in the
Mississippi Lowlands Division (Kentucky to Missouri south to Alabama and
Texas). Bottomland forests and swamps.
This species is
very similar to Q. palustris, and they are almost impossible to tell
apart without acorns. Quercus texana has a generally more southerly
distribution than does Q. palustris, but the ranges of the two species
overlap in southeastern Missouri and adjoining portions of adjacent states.
Acorn size can be very variable within some populations.