46. PINUS GLABRA

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

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.