[Illustration: PLATE III. FLOWERS AND CONELET]

THE CONE. Plate IV.

The cone of Pinus shows great differences of color, form and tissue;
these are useful for specific and sectional distinctions, while the
gradual change from the primitive conditions of the Cembrae to the
elaborate form, structure and mode of dissemination of some serotinous
species are obvious evidence of an evolution among the species of
remarkable taxonomic range. A form new among Coniferae appears, the
oblique cone, and a new condition, the serotinous cone, both appearing
at first alone and, finally, in constant association.

COLOR OF THE CONE.

With few exceptions the color of the ripe cone may be classified under
one of the following shades of brown or yellow.

Nut-brown The stain of the walnut-husk.
Rufous brown A pronounced reddish nut-brown.
Fulvous brown A yellowish nut-brown.
Tawny yellow The color of the lion.
Orange Ochre-yellow to red-orange.

These colors may be paler or deeper. They may be obscured by a fuscous
shade or may be modified by a dull or lustrous surface. The presence of
two or more of these shades in a single species and the inherent
difficulties of color description lessen the value of the character.
Nevertheless certain allied species, such as P. nigra and Thunbergii, or
P. densiflora and Massoniana, may be distinguished by the prevalent
difference in the color of their cones.

DIMENSIONS OF THE CONE.

The cone is small, medium or large in different species, but varies
greatly under the influences of environment or of individual
peculiarities. The character possesses relative value only, for great
variation is possible in the same locality and even on the same tree.

THE PEDUNCLE.

All conelets are pedunculate, but in some species the peduncle, even
when long (patula), may become overgrown and concealed by the basal
scales of the ripe cone. Articulation usually takes place between the
peduncle and the branch, sometimes with the loss of a few basal scales
which remain temporarily on the tree (ponderosa, palustris, etc.). With
P. Nelsonii, and to a less degree with P. Armandi, there is articulation
between the cone and its peduncle.

There are several species bearing persistent cones with no articulation.
This condition appears in other genera, such as Larix and Picea, but
without obvious significance. In Pinus, however, the gradual appearance
of the persistent cone,