f P. pungens, the spines are the
strongest and most persistent of all the species of eastern North
America.

Plate XXX.

Fig. 264, Cone. Fig. 265, Leaf-fascicle. Fig. 266, Magnified
leaf-section. Fig. 267. Magnified scales of the conelet.

46. PINUS GLABRA

1788 P. glabra Walter, Fl. Carol. 237.

Spring-shoots multinodal. Bark-formation late, the upper trunks of
mature trees smooth. Leaves in fascicles of 2, from 9 to 12 cm. long;
resin-ducts medial, hypoderm weak, sometimes of a single row, biform
when of two rows, endoderm with thin outer walls. Conelets reflexed,
mucronate. Cones from 4 to 7 cm. long, reflexed, ovate, symmetrical,
deciduous on some trees, persistent on others; apophyses pale dull
nut-brown, thin or slightly thickened, the prickle usually deciduous.

A tree that sometimes attains important dimensions, growing singly or
in small groves from the neighborhood of Charleston, S. C., to eastern
Louisiana and central Mississippi, most abundant in a strip of
territory on either side of the northern boundary of Florida. Among
the Pines of the southeastern United States it is the only species
with late bark-formation, and is therefore easily identified.

Plate XXX.

Fig. 256, Cone. Fig. 257, Enlarged scale of the conelet. Fig. 258,
Leaf-fascicle and magnified leaf-section. Fig. 259, Dermal tissues
of the leaf magnified, with a double row of hypoderm cells.

47. PINUS ECHINATA

1768 P. echinata Miller, Gard. Dict. ed. 8.
1788 P. squarrosa Walter, Fl. Carol. 237.
1803 P. mitis Michaux, Fl. Bor. Am. ii. 204.
1803 P. variabilis Lambert, Gen. Pin. i. 22, t. 15.
1854 P. Royleana Jamieson in Jour. Hort. Soc. Lond. ix. 52, f.

Spring-shoots multinodal, somewhat pruinose. Bark forming early, rough
on the upper trunk. Leaves in fascicles of 2 and 3, from 7 to 12 cm.
long; resin-ducts medial, with an occasional internal duct, hypoderm
weak, biform when of two rows of cells, endoderm with thin outer walls.
Conelets mucronate. Cones from 4 to 6 cm. long, ovate-conic,
symmetrical, often persistent; apophyses dull pale nut-brown, thin or
somewhat thickened along a transverse keel, the umbo salient, the mucro
more or less persistent.

This species ranges from southeastern New York to northern Florida, to
West Virginia and eastern Tennessee, and through the Gulf States to
eastern Louisiana, eastern Texas, southern Missouri and southwes