Porosity Pore Groupings Pore Arrangementxylem/WPS202/hardwood/pores.pdfMicroscope view (4x...
Transcript of Porosity Pore Groupings Pore Arrangementxylem/WPS202/hardwood/pores.pdfMicroscope view (4x...
POROSITY
• RING POROUS
• DIFFUSE POROUS
• SEMI- RING POROUS(Semi-Diffuse Porous used in ID Book)
DEFINED BY SIZE DISTRIBUTION OF VESSELSWITHIN ONE GROWTH RING
(about same size throughout or larger in earlywood)and the
TRANSITION FROM EARLYWOOD TO LATEWOOD (gradual or abrupt).
RING POROUS
• Earlywood zone with widevessels (pores)
• Earlywood zone about samesize each year.
• Abrupt transition to latewoodzone with narrow vessels(pores), latewood zone variablewidth
• Common in temperate USwoods, rare in tropical trees.
Ash, Fraxinus
Red Elm, Ulmus rubra
DIFFUSE POROUS• Vessel diameter about the same in earlywood and
latewood
• Vessels throughout growth ring.
• Growth rings less obvious than in ring porouswoods
Yellow Poplar, Liriodendron tulipifera Birch, Betula sp.
DIFFUSE POROUSHOLLY, Ilex aquifolium BLACKGUM, Nyssa
Which one likely has the higher specific gravity?
Holly with less vessel volume
Persimmon Pecan
Diospyros virginiana Carya illinoisensis
SEMI-RING POROUSVessel diameter gradually decreases from earlywood to latewood
VESSEL GROUPINGS: Solitary
Handlens View of Red OakAll vessels solitary
Microscope view (10x objective)Tropical Vine. All vessels solitary
VESSEL GROUPINGS:Solitary and in Radial Multiples
Handlens view of Birch.Vessels solitary and inshort radial multiples
Microscope view (4x objective)Mahogany. White ovals surround some
radial multiples of 2 and 3 vessels
MMOOSSTT
CCOOMMMMOONN
VESSEL GROUPINGS: CLUSTERS
Handlens View of Black LocustLatewood vessels in clustersClusters connected by axial parenchyma
Cluster = a group of vessels, someside by side tangentially as well asradially.
Vessel clusters occur in combinationwith solitary vessels and radialmultiples.
Not common.
In U.S. woods, see in latewood ofsome ring porous species.
PORE ARRANGEMENT
• RANDOM
• TANGENTIAL LY
• RADIALLY
• OBLIQUE / DIAGONAL
• DENDRITIC / FLAMELIKE
NOTE: THESE VESSEL ARRANGEMENT PATTERNS OFTENINTERGRADE, ESPECIALLY RADIAL AND OBLIQUE / DIAGONAL
VESSEL ARRANGEMENT: Random
Handlens view of Birch (Betula).Random arrangement of vessels(vessels are solitary and in short
radial multiples )
Microscope view (10x objective)Tupelo (Nyssa ). Random arrangement
of vessels (vessels solitary & in shortradial multiples)
TANGENTIAL ARRANGEMENT
Handlens view. Ulmus americanaLatewood in wavy tangential bands,
solitary row of earlywood vesselsWide growth rings.
Microscope view (4x objective)American Elm. Narrow growth rings,earlywood solitary row, latewood with
tangential bands of vessels.
RADIAL to DENDRITIC
Handlens view. White oak.Latewood with very small vessels in a
radial to dendritic arrangement
Handlens view. ChestnutLatewood with very small vessels in a
radial to oblique to dendriticarrangement