Forestry 280 Features of Woods 28-47

Forestry 280Features of Woods 28-47

#28: Red Oak Quercus rubra

Earlywood Pores

Latewood Pores

Wide, oak-type ray

#29: White Oak Quercus alba

Banded

Parenchyma

#30: Live Oak Quercus virginiana

Semi-ring to diffuse porous; growth ring boundaries may be difficult to detect

Broad, oak-type ray Aggregate ray Narrow rays also

present

#31: American Chestnut Castanea dentata

Structure similar to oaks, but no wide, oak-type rays

Typically lower in density than oak

Tyloses often found

“Flame-shaped groups of LW pores”

#32: American Elm Ulmus americana

Single row of EW pores

LW pores in “wavy bands” (“ulmiform”)

#33: Slippery Elm (or Red Elm)Ulmus rubra

EW Pores often in “several” rows (2-6)

WOW! Look at those ULMIFORM LW PORES!

#34: Rock Elm Ulmus thomasii

Earlywood Pores: Small and indistinct in intermittent, single row “A single interrupted

row separated by smaller pores”

#35: Hackberry Celtis occidentalis

Heartwood Color: Cream, light brown or light grayish brown w/yellowish cast

Earlywood: More than one pore wide (akin to Slippery Elm)

Latewood: Pores in wavy bands!! (Hackberry is in the Ulmaceae, or elm family)

#36: Red Mulberry Morus rubra

Loaded with tyloses! But, some samples have few to no tyloses…

LW Pores are in “nestlike groups”…sometimes forming concentric, interrupted bands – but not nearly so pronounced as in the elms.

#37: Osage Orange Maclura pomifera

LW pores in nested groups that form distinct concentric bands

LOADED WITH TYLOSES: “USUALLY COMPLETELY OCCLUDED”

#38: Kentucky Coffeetree Gymnocladus dioicus

Nested LW pores more isolated, sometimes coalescing

EW Pores in 1-few rows; open (no tyloses)

#39: Honeylocust Gleditsia triacanthos

Looks a lot like Coffeetree – Don’t separate!!

Note the heartwood color of #38 & 39

#40: Black Locust Robinia pseudoacacia

Pores often completely occluded with tyloses

Note LW pore pattern!

#41: White Ash Fraxinus americana

Avg. SG: 0.60 Heartwood Color: Light brown

or grayish brown Sapwood Color: Creamy white Pore Distribution: Ring-porous Earlywood: 2-4 pores wide;

pores mod. large, surrounded by lighter tissue

Latewood: Pores solitary and in radial multiples of 2-3

Tyloses: Fairly abundant Rays: Not distinct to eye, but

clearly visible w/hand lens

#42: Black Ash Fraxinus nigra

Avg. SG: 0.49 Heartwood Color: Grayish

brown to medium or dark brown Sapwood Color: Creamy white Pore Distribution: Ring-porous Earlywood: 2-4 pores wide;

pores large, surrounded by lighter tiss.

Latewood: Pores solitary and in radial multiples of 2-3; not numerous

Tyloses: Fairly abundant Rays: Not distinct to eye, but

clearly visible w/hand lens

#43: Catalpa Note heartwood color Note lw pore patterns

Tyloses “variably abundant”

#44: Butternut Juglans cinerea

Avg. SG: 0.38 Heartwood Color: Medium or

cinnamon brown, often w/uneven streaks of color, fluted growth rings

Pore Distribution: Semi-ring-porous

Pores: Earlywood pores fairly large, decreasing to small in latewood, solitary or in radial multiples of 2 to several

Tyloses: Moderately abundant Parenchyma: Short tangential

lines of banded parenchyma visible w/hand lens

Rays: Fine but visible

#45: Black Walnut Juglans nigra

Avg. SG: 0.55 Heartwood Color: Medium

brown to deep chocolate brown Pore Distribution: Semi-ring-

porous Pores: Earlywood pores fairly

large, decreasing to quite small in outer latewood, pores solitary or in radial multiples of 2 to several

Tyloses: Moderately abundant Parenchyma: Short tangential

lines of banded parenchyma visible with lens

Rays: Fine, visible but not conspicuous w/lens

#46: HickoryA True Hickory: Shagbark Hickory Carya ovata

Note the “fishnet” (or “lace-like”) pattern in lw, formed by intersection of the fine rays and banded parenchyma

True hickories are ring-porous

#46: Hickory - Pecan Hickory Carya illinoensis

Pecan hickories are semi-ring porous…this looks like a poor example! (See next slide)

What are these diagonal, whitish lines???

#46 - Hickory, Carya, spp.

True Hickory Pecan Hickory

#47: Tanoak Lithocarpus densiflorus

Wood is DIFFUSE porous

The wide rays are “aggregate rays” that tend to be irregularly-spaced on the cross-section

Acknowledgement Photomacrographs by Zach Kriess Supplemental photomacrographs (those with

white text showing scientific name) courtesy of the USDA Forest Service, Forest Products Laboratory