Knob Cone Pine TreeThe Knob-Cone Pine (P. attenuata, Lemm.) is another tree of striking habit. Its cones are woody, armed with stout beaks, and from 3 to 5 inches long. There is nothing peculiar in these cones, nor in the pale yellow-green foliage in its 3-leaved clusters. The tree is slim and tall, and grows on the hot, dry fire-swept foothills of California mountains. A stranger notes how dense and uniform in size is the growth of these trees, and how thickly studded are the limbs with clusters of cones. Close examination shows them sealed up tight-not a scale sprung on the oldest cone, though the branch that bears it may have actually swallowed the cone by the increase of its diameter.
A fire sweeps over the slope, and every tree gives up its cones. The scales are unsealed at last and the seeds, whose vitality has been preserved, apparently, in anticipation of this day, germinate at once, and soon a new forest takes the place of the old one. With such an abundance of seed, is it wonderful that the trees stand close and even like wheat in a field?