growth rings page


SOME WOODS WITH SEMI RING POROUS GROWTH RINGS
NOTE: semi diffuse porous woods and semi ring porous are intermixed on these pages
(but are usually commented on as being most reasonably one or the other)


NOTE: unless otherwise specifically stated, all of the images shown on this
page are of 1/4" square end grain cross sections shown at 12X with the top
of the image towards the bark and the bottom towards the pith so that
earlywood is towards the bottom of the growth rings and latewood is towards the top


There are numerous species on this page so I have divided them into the following arbitrary groups to facilitate your finding what you are looking for:




Group 1: reticulate parenchyma
classic semi ring porous with a clear row of earlywood pores
that only gradually reduce in size over the course of the year's growth
rays are present and generally visible with a 10X loupe
(but never with the naked eye)
growth ring boundaries are clear to the naked eye
reticulate parenchyma, usually obvious and easily visible at 10X (sometimes vague)
varying quantities of pore multiples from few to many


THIS GROUP CONTAINS ONLY HICKORY AND PECAN


Hickory and pecan are in the same genus and their ring structure is almost identical at the level of a 10X loupe (see below for the difference). The National Hardwood Lumber Association does not distinguish between the two and neither do most lumber yards, lumping all Carya species into hickory or, less often, pecan or even hickory/pecan. Anecdotally, I have heard conflicting statements, one saying that experienced sawyers can tell the difference and the other saying that even experienced sawyers cannot tell the difference. I'm talking there about AFTER the lumber is separated from the bark and there are no "tree" clues to go by. The TREES can be distinguished but this site is about lumber.

general characteristics of hickory and pecan --- a clear row of earlywood pores that only gradually reduces in size over the course of the year's growth. Rays are present and generally visible with a 10X loupe but never with the naked eye and the same is true for the multitudinous banded parenchyma lines. Growth ring boundaries are clear to the naked eye. The single distinguishing characteristic is that the hickory group has no banded parenchyma in the rows of earlywood pores whereas the pecan group has banded parenchyma throughout. See this link for detailed images: HICKORY VS PECAN

     

     

     

     

     

     

     

   

     

        

     

 



Group 2: diffuse-in-aggregate parenchyma
semi ring porous with a slightly vague row of earlywood pores
that only gradually reduce in size over the course of the year's growth
multitudinous diffuse-in-aggregate parenchyma lines are present
(but sometimes hard to see even with a 10X loupe)
rays are present but usually are hardly visible even with a 10X loupe



butternut --- growth ring boundaries are fairly clear to the naked eye (may be vague occasionally)

     

     

 


walnut --- generally semi diffuse porous but occasionally looks a bit like semi ring porous, pore density is medium, rays are present but often hard to see even with a 10X loupe, diffuse in aggregate parenchyma is present but usually hard to see even with a 10X loupe, pores sometimes grow next to each other but actual pore multiples are rare, growth ring boundaries are usually clear with a 10X loupe, but they are often vague to the naked eye. NOTE: tropical walnuts are diffuse porous and are on that page.

     

     

     

     

 

       
NOTE: most of my Juglans hindsii samples were from very fast-growth areas of their trees

   
     
     



Group 4: strong rays
This group is misc semi diffuse and semi ring porous with
ray that are close together and easily visible with a 10X loupe but not necessarily to the naked eye


   
almond --- pores are sparse and small, growth ring boundaries are sometimes vague


tamarisk --- semi diffuse porous but sometimes looks more diffuse porous than semi diffuse; always shows strong rays although it varies some among the species.

     

     
these three samples are all from the same bole section

     



Group 5: winged aliform parenchyma
winged type aliform parenchyma, sometimes with long wings
pores medium to small, fairly sparse, pore multiples are rare
growth rings faint to invisible, even with a 10X loupe


     

 
narra --- winged aliform parenchyma and short tangential parenchyma bands

     



Group 6: strong line of earlywood pores
semi ring porous with a very heavy line of earlywood pores
that only gradually reduce in size over the course of the year's growth
growth ring boundaries are obvious to the naked eye


     

   


redbud --- ulmiform pore bands but much weaker than in elm

     

     

     



Group 7: thick vasicentric parenchyma
large/moderate sized rays having thick vasicentric parenchyma
rays always present, usually easily visible at 10X but never to the naked eye


   

   
camphor --- really hard to call as either semi ring porous or semi diffuse porous. Fairly dense medium sized pores with thick vasicentric parenchyma, rays are present but tiny and often hard to see even with a 10X loupe, growth ring boundaries are clear even to the naked eye due to a darkening of the tissue at the end of the latewood and a slight thinning of the pores at the end of the latewood

   

   

     

   
teak --- semi ring porous with a clear row of earlywood pores that only gradually reduce in size over the course of the year's growth. Rays are present and usually quite clear at 10X but never visible to the naked eye. Thick vasicentric parenchyma is easily visible with a 10X loupe, growth ring boundaries are very clear to the naked eye

     
amendoim --- semi diffuse porous, growth ring boundaries vague

       

 



Group 8: relatively sparse pores
relatively sparse pores, a slightly vague row of earlywood pores
that only gradually reduce in size over the course of the year's growth
but often not visible even with a 10X loupe.
rays are present but hardly visible even with a 10X loupe



persimmon --- can be either semi ring porous, semi diffuse porous or diffuse porous and several species are shown on the domestics diffuse porous page. Rays are present but often hard to see even with a 10X loupe, pores are medium sparse to sparse, growth ring boundaries of the "semi-" species shown on this page are discernible with a 10X loupe but may be vague to the naked eye. Diffuse in aggregate parenchyma bands are present but usually not visible even with at 10X

   

   

   

   

   




     

     
sugar sumac --- note that this Rhus species is semi diffuse porous --- my other sumacs (Rhus species) are ring porous page and are on that page. The Rhus species are a good example of how hard it sometimes is to make any general statement about some species.
     

   



Group 9: small, medium density pores, obvious rays
medium density, very small pores, a thin, sometimes vague, row of earlywood pores
that only vary slightly in size over the course of the year's growth,
growth ring demarcation is weak but generally visible to the naked eye
rays are clear with a 10X loupe but not to the naked eye

Note: the common name buckthorn includes two different genera that look alike at the tree level but have radically different characteristics at the wood anatomy level. Rhamnus is one and Frangula is the other. The Rhamnus species here in my anatomy pages are diffuse porous and are on the domestic diffuse porous page.

   

     

     



Group 10: semi diffuse porous with particularly obvious growth ring boundaries due to very significant color change from latewood to the next earlywood, rays are numerous but weak (sometimes visible with a 10X loupe)


I have noticed that it is fairly common for serviceberry to have short streaks of what I assume are gum deposits (they look a bit like the resin canals of softwoods). You can see these as dark blotches in several of these end grains. On face grain, they look like the gum streaks that I believe them to be.

     

     

     



Group 11: OTHER semi ring porous and semi-diffuse porous species that do not fit readily into the other categories above