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).

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.

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.

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.

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.

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.

Baby Doug

Day 153: Here in the Pacific Northwest, our lower forests tend to be "mixed" stands of evergreens with the occasional incursion of deciduous trees like Red Alder or Cottonwood following stream channels or populating wetlands. Cedar is easy to identify, as is Hemlock, but things get a little stickier when it comes to telling Sitka Spruce from Douglas Fir, especially when the trees are young and no cones are available for analysis. The easiest way to tell them apart is to compare cross-sections of a needle. Fir needles are flat, and spruce needles are square. A fir needle will not roll between your finger and thumb, but a spruce needle will. Spruce needles are stiffer and the ends feel sharp. Fir needles are more flexible and the ends are blunt. This baby Doug (Pseudotsuga menziesii) has found a wonderful moss-covered "nurse" to nurture it to adulthood.