Forestry 280: Hand lens cross-sections,Woods 14-27: Softwoods without normal resin canals

Views are presented to approximate observation with a 10x hand lens (some also with approx. 20x view). Thus, both specimen imperfections and some lack of detail will be evident.

Many of the woods in this set are distinguished mainly by heartwood color, heartwood odor, wood hardness (or in some cases, “brittleness”) and texture. Macroscopic anatomical variation of these woods is limited, thus these “secondary” macro features become of greater importance for macro identification.

Images with species name shown in white on the photograph are courtesy of the USDA Forest Service, Center for Wood Anatomy Research.

#14 – Eastern hemlock, Tsuga canadensis

Wood rather brittle, “harsh” or splintery.

Often with a foul, somewhat rancid odor.

Latewood often showing a “roseate to reddish cast.”

Don’t separate the hemlocks…#14 (Eastern) and #15 (Western)

#15 – Western hemlock, Tsuga heterophylla

Not as brittle or splintery as Eastern hemlock; a better construction wood as a result.

Heartwood color and grain appearance (latewood prominence on flat-sawn, tangential-longitudinal surfaces) may be a distinctive feature on larger pieces (see classroom display sample for a good example).

#16 – Balsam fir, Abies balsamea

Wood light and soft. Heartwood color is light,

rather “creamy” sometimes with a “lavender” tinge.

True firs (Abies sp.) are sometimes confused with spruces (Picea) but the latter have resin canals.

Balsam fir sometimes has a very foul odor due to a condition in the standing tree known as “bacterial wetwood.”

#17 – Western firs, Abies sp.

Don’t separate the true firs (#16 and #17).

DO, however, make a distinction between true fir (Abies sp.) and Douglas fir (Pseudotsuga) when necessary!

#18 – Redwood, Sequoia sempervirens

Note: This illustration appears to combine two separate photos. Lower half looks more representative of the species – shows coarse texture (large tangential diameter of longitudinal tracheids).

Heartwood color of redwood is usually a notable identifying feature. Does NOT have a distinctive heartwood odor.

#19 - Baldcypress, Taxodium distichum

Note typical, extreme variation in growth ring width.

Wood is coarse textured, rather hard and heavy; may have “peckiness” (decay zones) – see classroom display sample for example.

Most samples in our collection do not exhibit any appreciable heartwood odor.

#20 – Incense cedar, Calocedrus decurrens

Faint to pungent cedar smell, “like wooden pencils”….however, some pencils today are made with Yellow Poplar (Liriodendron tulipifera) or with a wood sawdust-plastic composite material!

Some samples exhibit “peckiness” – don’t confuse this species with baldcypress (#19) just because of this!

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20x

#21 – Northern white cedar, Thuja occidentalis

Heartwood generally uniformly “straw brown.”

Heartwood odor is “cedar-like” but is generally quite faint.

It can be rather difficult to distinguish Northern White (#21) from Atlantic White (#25).

#22 – Western redcedar, Thuja plicata

Heartwood odor in many samples is “sweet” and distinctive; “like shingles.”

Rather coarse textured, generally straight grained with uniform ring width; heartwood color generally uniformly light-medium brown.

#23 – Port Orford cedar, Chamaecyparis lawsoniana

Wood is light, soft, straight-grained, and generally light and “creamy” to pale yellowish in color.

The “sweet, ginger-like” heartwood odor is the primary distinguishing feature of this species!

#24 – Alaska yellow cedar, Chamaecyparis nootkatensis

Heartwood odor often described as resembling “raw potatoes” but in recent years, some students have noted that it smells rather like the Asian lady-beetles that have invaded the Midwest lately!

Heartwood color usually very light with a distinct yellowish cast.

#25 – Atlantic white cedar, Chamaecyparis thyoides

Heartwood odor is usually faint, but some samples in our collection have a very pleasing, sweet cedar smell.

Rather fine textured, with light, yellow-brown heartwood color.

#26 – Eastern redcedar, Juniperus virginiana

Heartwood is “purplish,” often with light, creamy streaks of “included sapwood” surrounded by the heartwood.

Often from small trees, so most samples have sapwood, heartwood, and included sapwood.

Separate from Pacific Yew by heartwood color, included sapwood, cedar odor (in most samples of #26), and relative hardness (Yew generally very hard).

#27 – Pacific yew, Taxus brevifolia

Wood very hard, heavy, and fine textured.

Usually from small trees; many samples have bark, sapwood and heartwood.

Heartwood color (samples in our collection) more brownish than #26, E. redcedar, which has a more “purple” cast in the heartwood color.

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