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Thursday, January 19, 2012

Pinus thunbergii - Japanese Black Pine

The Japanese Black Pine is a beautiful if not irregular shaped evergreen conifer, generally growing slowly to 25' or so feet in cultivation, but can be 100' in its native habit. Usually dark green but can be yellowish in some areas around here. Know for it's picturesque habit and beautiful bark, its also a popular specimen for Bonsai. There are several in this picture below.





The needles are in clusters of 2's, 3 - 4-1/2" long, stiff, sharply pointed, held on stem at about 45 - 60 degree angle. Generally dark green but can be yellowish-green. The cluster are called fascicles and the whitish area at the base is called the sheath which on this species is about 1/2" long.



Stems are yellowish brown, scaly. You can see the sheath clearly in this image.



Terminal buds are white and quite attractive and a good identification characteristic. Few of the others around here will have such a nice white terminal bud.  The little cones below the bud in this image are immature cones from last year, as soon as the terminal bud starts to grow the cones will start as well.



Mature cones are rounded to oval, 1-1/2 - 3" long, yellowish brown at maturity and borne in clusters up to 10 or so, but may also be solitary.



Bark is dark gray to black, deeply furrowed with scaly patches.



Bonsai specimen or two.






Misidentification: Count the needles, there are 2. They are stiff, sharply pointed and usually dark green. Small stature tree, thick dark bark, smaller cones.

Other 2 needle pines here:
P. cembrioides, very short needles, small tree, tiny cones with pinyon seeds.
P. controta, has very short leaves and very much smaller cones, not really common.
P. densiflora has very thin leaves and every much smaller cones as well as being clustered, less common as well.
P. halepensis has thin leaves, found on the freeways usually.
P. mugo, small shrub generally,
P. nigra, leaves dark, stiff, white buds, yellowish tan cones, 
P. pinea, leaves thicker, stiffer, look for the leaves on new shoots on this one to be laying almost flat and forward as well as being retained longer.
P. sylvestris, bluish green leaves, distinctly twisted, smaller cones, reddish bark, not common.
P. thunbergii, thicker needles, often yellowish green, very sharp and usually twisted.

Hope to cover these later.

Location: Rio Del Mar shopping center, especially the South end
Soquel Dr just North of Park is a row of them and they are showing the variability typically seen.

3 comments:

  1. Dear Mr. Shaw -

    I'm working with the New England Wild Flower Society to obtain images for our new online field guide of plants of the Northeast US, called Go Botany! The site is up and operational, but we are still in need of specific images to fill in some gaps. Your photos of Pinus thunbergii bark and Ulmus parvifolia flowers that I viewed on your blog would make great additions to the key. Would you be interested in granting us permission to use these images? Your name will appear with each image used.

    ReplyDelete
    Replies
    1. Sorry, I forgot to leave my name.

      Tom Warhol
      Botanical Data Specialist
      New England Wild Flower Society

      Delete
  2. Of course you may use the photos, cheers

    ReplyDelete