20. Pinus glabra Walter, Fl. Carol. 237. 1788. Trees to 30m;
trunk to 1m diam., straight; crown conic to rounded. Bark gray,
fissured and cross-checked into elongate, irregular, scaly
plates, resin pockets absent, on upper sections of trunk ±
smooth, gray, looking slick. 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--1cm, slightly resinous; scale margins finely
fringed. Leaves 2 per fascicle, spreading to ascending,
persisting 2--3 years, 4--8(--10)cm ´ 0.7--1.2mm, straight,
slightly twisted, dark green, all surfaces with fine stomatal
lines, margins finely serrulate, apex sharply conic; sheath 0.5
--1cm, base persistent. Pollen cones lance-cylindric, 10--15mm,
purple-brown. Seed cones maturing in 2 years, shedding seeds
soon thereafter, semipersistent, spreading to recurved, nearly
symmetric, lance-ovoid before opening, ovoid-cylindric when
open, 3.5--7cm, red-brown, aging gray, nea