Showing posts with label Douglas Fir. Show all posts
Showing posts with label Douglas Fir. Show all posts

Sunday, February 24, 2019

Fake Fir



Day 134: Western Washington clothes her shoulders in a garment trimmed largely with fake fir. Douglas Fir, icon of Pacific Northwestern forests, is not a true fir; true firs such as Grand and Noble bear cones which stand erect from their branches. Doug Fir cones hang down from their point of attachment. The scales of Doug Fir cones are also "persistent," i.e., they do not fall apart after releasing their seeds and remain attached to the central core. Ironically, the scientific name of Douglas Fir (Pseudotsuga) means "false hemlock," undoubtedly reflecting the similiarity in the tree's needles, less spiky than those of true firs (genus Abies).

Sunday, January 27, 2019

There's Gold On Them Thar Trees


Day 106: "There's gold on them thar trees!" Yes, and not just on the north side, scout. Sorry to disappoint, but that's a myth, and one I've never been able to understand. Lichens and mosses grow on the MOIST side of trees, and as anybody who lives in the Pacific Northwest can attest, sometimes that means all the way around. That said, a walk through our conifer forests will often cause an observer to comment on trees crusted with Chrysothrix candelaris, Mother Nature's version of tagging trees with her yellow-gold "spray paint." Commonly called "Gold-Dust Lichen," one of its most popular substrates is the thick bark of Douglas fir. Some experts claim that it can be differentiated from other Chrysothrix species by granule size when they occur in the same region (a contentious subject), but here in the PNW, it's a pretty safe bet to call any gold-bearing seams on Doug fir by the name C. chrysothrix.

Saturday, July 14, 2018

Cooley Spruce Gall Adelgid On Douglas Fir



Day 274: Some forms of the Cooley Spruce Gall Adelgid (Adelges cooleyi) spend a portion of their life cycle solely on Douglas fir while others migrate from fir to spruce as the insects reach maturity. On spruce, an infestation of Adelges cooleyi may form unsightly galls on branch tips, but these galls do not form on Douglas fir. According to the Oregon Dept. of Forestry, "The conspicuous presence of woolly adelgids on Douglas-fir foliage and the galls produced by this same insect on branch tips of spruce generate more public inquiries than any other forest insect. In natural stands the presence of the Cooley spruce gall adelgid is of little consequence, but severe infestations on ornamental trees, nursery stock, or Christmas trees may justify control. The damage caused by this insect affects only aesthetics and does not threaten tree survival." Adelgids are more likely to occur on stressed trees than on healthy ones, as evidenced by this infestation on a young fir struggling for survival in rocky, dry fill. The white, cottony masses shown in this image are the waxy secretions produced by the insect which helps it adhere to the branch and affords it protection from other insect predators. A few unconcealed Adelgids can be seen here as tiny black spots.

Wednesday, March 22, 2017

Ragbag And Mouse Bottoms



Day 160: Platismatia glauca ("Ragbag" or Varied Rag Lichen) is almost as common in Pacific Northwest forests as Doug fir cones. It is easily recognized by its pale grey-green colour, "limp dishrag" feel and brownish lower surface. Closer observation may reveal soredia on the margins of the lobes. These are "mini-lichens," reproductive structures capable of taking hold in the appropriate medium to become new colonies. Shown here with a fir cone for size comparison, the soredia are barely visible on this fresh, verdant specimen.

As for that fir cone, there's a widely circulated story about Grandfather Douglas Fir giving shelter to the creatures of the forest during a fire. It is not an authentic legend despite popular belief, but it's entertaining nevertheless. During the fire, the frightened animals ran to old Douglas Fir to plead for refuge from the flames, knowing that the Fir's thick bark protects the tree and allows it to survive all but the hottest fires. The elk left footprints on the interior of the cone's scales and the outline can be seen if you peel a dry scale away (mine were too wet). However, the mice were rather late in their approach and when they asked Doug Fir to harbour them, he said, "I don't know...it's awfully crowded in here, but you can try to squeeze in." The mice did so, but couldn't get all the way inside. You can see their little bottoms sticking out of the cone in this picture.

Sunday, February 21, 2016

Hypogymnia Imshaugii, Forked Tube Lichen



Day 131: The Hypogymnias are abundant in my area (even in my own yard) and more than one species frequently occurs on the same branch. Forked Tube has a couple of look-alikes, but these can be sorted out fairly easily by opening one of the "tubes" which give this family its common name. Hypogymnia imshaugii has a white medullary ceiling, clearly visible in the broken tube just left of the two apothecia on the right, less distinct in the tube in the "ten o'clock" position left of the largest apothecium. Both H. inactiva and H. heterophylla have a black/dark ceiling. H. inactiva generally shows more black as well, often extending into the upper surface from the underside of the thallus. H. heterophylla is not as regularly branched.

Needless to say, I didn't get much done in the way of yard cleanup today, what with damp weather and a whole raft of lichens brought down during the winter storms. Priorities...it's all about priorities.

Friday, February 19, 2016

A Positive Reaction


Day 129: Well, this was fun! One of the methods of determining a lichen identification involves testing certain areas of the specimen with common chlorine bleach. A positive reaction (i.e., a colour change) can be useful for differentiating species.

My sample was collected from a Douglas fir (Pseudotsuga menziesii), the first clue as to its identity. However, I was not certain that I was observing a secondary interior exciple ring in the well-developed disks, a feature which would have solved the mystery in the field. The larger size of the disks seemed to rule out Trapeliopsis which is generally under 1.5 mm., but just in case I had a whole forest full of atypical specimens (not likely!), chemical testing was in order. Upon applying a drop of bleach to one disk, it turned distinctly red, as did the thallus when the bleach came into contact with it during a second test. Given that the specimen was taken from Doug fir and that it showed a C+ reaction in both the thallus and apothecia, I am confident in stating that the lichen in the photo is Ochrolechia oregonensis, Double-rim Saucer Lichen. Its close cousin O. laevigata (Smooth Saucer, featured previously in this blog) grows on deciduous trees as opposed to conifers.

Friday, January 22, 2016

Chrysothrix Candelaris, Gold Dust Lichen


Day 101: If you've done any hiking in the Pacific Northwest, you've undoubtedly encountered evergreen trees (notably Douglas Fir) with a strange greenish-gold coating on the bark. If you looked more closely, you probably thought there was nothing particularly noteworthy about it, or if you touched it, you would have found it powdery on the surface, but impossible to wipe off entirely. There your curiosity was likely to have ended, and if you remarked on it at all, you simply said to yourself, "Weird yellow-green dust on a tree, okay" before moving on to showy wildflowers and butterflies in the meadows.

Would it surprise you to know that this is a lichen? Its common name is particularly descriptive: Gold Dust. Note the fir needle just right of center for a size reference. That will give you an idea how fine the texture is. Scientifically, it is known as Chrysothrix candelaris, a reference to its resemblance to another lichen family, the Candelarias.

Tuesday, December 2, 2014

Fir Fur



Day 50: I went walking during a slow time at work today with my mind focused on taking photos of the larger winter scene, but it was not icicles hanging from the buildings at Longmire which caught my eye, nor the clear prisms of ice dangling from every bough. It was not the waterfalls halted in mid-flow, nor the unsullied white canvas of Longmire Meadow. It was the sight of one brave young Douglas fir defying the soulless frost, a paradigm of survival, which gave the dimensions of the season's footprint. I read in this stalwart, strapling youth's determination a lesson it would do well for us all to remember: in adversity, you will come to know that you are greater than you believe yourself to be.

Tuesday, August 5, 2014

The Dubious Legend


Day 309: The authenticity of this purported "legend" is very much in doubt, but it is a charming story and bears repeating...with an appropriate disclaimer, of course. This much, however, is true. The bark of the Douglas Fir is very thick, a feature which allows it to survive forest fires which obliterate more vulnerable species. That information is critical to the tale which follows.

You see, there was a massive fire many years ago, a fire which swept through the lush forests of the Pacific Northwest. Fearing for their lives, the animals ran to the chief of all the evergreens for aid. "Douglas Fir! Douglas Fir!" the elk cried. "Can you save us? We are afraid! Protect us, because you alone can survive the fearsome fire!"

Douglas Fir told the elk, "You elk, you can come into my cones. There I will be able to protect you." The elk squeezed into Douglas Fir's cones, leaving the imprint of their hooves on the interior of the scales.

The fire burned more fiercely, and the mice ran to the father of the forest. "Douglas Fir! Douglas Fir! The fire is coming nearer! We are going to die unless you help us!"

Douglas Fir told the mice, "I have the elk inside my cones already, but you are welcome to try to fit in."

The mice squeezed and squeaked, but just as Douglas Fir had said, there was very little room. The mice managed to get their heads inside, but they left their bottoms and tails sticking out. You can see them if you pick up a Douglas Fir cone, and if you open it, you'll see the elk prints inside.