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Forestry 280 Features of Woods 28-47. Wide, oak-type ray. #28: Red Oak Quercus rubra. Latewood Pores. Earlywood Pores. Ray. EW Pores. LW Pores. Tyloses. Banded Parenchyma. #29: White Oak Quercus alba. #30: Live Oak Quercus virginiana. - PowerPoint PPT Presentation
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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