Resin Birch? (publ. 2023-08-16)

I have been wondering about a tree/shrub which I had previously classified as a "mystery tree" (see my August 2 2023 post). Here are some photos, from a walk yesterday, of the leaves and branches:

mystery tree/shrub leaves

mystery tree/shrub branches

In size and shape, it seems something in-between a tree and a bush.

Reading in "Alaska Trees and Shrubs" (2nd ed., Viereck et al), it appears to be a "Resin Birch" (betula glandulosa Michx.). I thought paper birch was the only birch found in interior Alaska, but apparently resin birch is quite common throughout most of Alaska. I had little trouble finding more of this plant, once I knew what I was looking for. It tends to be found on moist ground, however, so one must look near ponds or places where water-runoff tends to collect.

The things I observed that match up with the description in the book (pg. 159):

- "Decidious shrub low and spreading to erect, 0.3 to 1.5 m tall or taller, forming clumps"

- "Short, hair petioles 5 to 6 mm long."

- "Blades broadly obovate, mostly 1 to 2 cm long, rounded but longer than broad; rounded at apex, with fine, wavy teeth except near wedge-shaped base."

- Bark is "reddish-brown, becoming dark gray, smooth, nonpeeling.

And the sketches in the book look very similar. The part that doesn't quite fit is the branches are not exactly "smooth" but have many little white dots or bumps. The next entry in the book (pg. 162) mentions that there are many hybrid birches in Alaska, so maybe this is some variant. I didn't see any catkins or cone-like fruits on these trees at present, or I would have tried to compare those with the sketches in the book.