Fig. 135. Wood of Hickory.
(A few indistinctly ring-porous woods of Group II, D, and cedar elm may seem to belong here.)
| A. Pores varying in size from large to minute; largest in spring wood,
thereby giving sometimes the appearance of a ring-porous arrangement. | |
| 1. Heavy and hard; color of heart-wood (especially on longitudinal
section) chocolate brown. | Black Walnut. |
| 2. Light and soft; color of heart-wood light reddish brown. | Butternut. |
| B. Pores all minute and indistinct; most numerous in spring wood,
giving rise to a lighter colored zone or line (especially on
longitudinal section), thereby appearing sometimes ring-porous;
wood hard, heart-wood vinous reddish; pith rays very fine, but very
distinct. (See also the sometimes indistinct ring-porous cedar elm,
and occasionally winged elm, which are readily distinguished by the
concentric wavy lines of pores in the summer wood). | Cherry. |
| C. Pores minute or indistinct, neither conspicuously larger nor more numerous
in the spring wood and evenly distributed. | |
| 1. Broad pith rays present. | |
| a. All or most pith rays broad, numerous, and crowded,
especially on tangential sections, medium heavy and hard,
difficult to split. | Sycamore. |
| b. Only part of the pith rays broad. | |
| a'. Broad pith rays well defined, quite numerous;
wood reddish white to reddish. | Beech. |
| b'. Broad pith rays not sharply defined, made up of many
small rays, not numerous. Stem furrowed, and therefore the
periphery of section, and with it the annual rings sinuous,
bending in and out, and the large pith rays generally limited
to the furrows or concave portions. Wood white, not reddish. | Blue Beech. |
| 2. No broad pith rays present. | |
| a. Pith rays small to very small, but quite distinct. | |
| a'. Wood hard. | |
| a". Color reddish white, with dark reddish tinge in outer
summer wood. | Maple. |
| b". Color white, without reddish tinge. | Holly. |
| b'. Wood soft to very soft. | |
| a". Pores crowded, occupying nearly all the space between
pith rays. | |
| a'". Color yellowish white, often with a greenish tinge in
heart-wood. | Tulip Poplar. |
| | Cucumber Tree. |
| b.'" Color of sap-wood grayish, of heart-wood light to dark
reddish brown. | Sweet Gum. |
| b". Pores not crowded, occupying not over one-third the
space between pith rays; heart-wood brownish white to
very light brown. | Basswood. |
| b. Pith rays scarcely distinct, yet if viewed with ordinary magnifier,
plainly visible. | |
| a'. Pores indistinct to the naked eye. | |
| a". Color uniform pale yellow; pith rays not conspicuous
even on the radial section. | Buckeye. |
| b". Sap-wood yellowish gray, heart-wood grayish brown; pith
rays conspicuous on the radial section. | Sour Gum. |
| b'. Pores scarcely distinct, but mostly visible as grayish specks on
the cross-section; sap-wood whitish, heart-wood reddish | Birch. |
| D. Pith rays not visible or else indistinct, even if viewed with magnifier. | |
| 1. Wood very soft, white, or in shades of brown, usually with a silky
luster. | Cottonwood (Poplar). |
