Larix occidentalis “Western Larch” Pinaceae

Rattlesnake National Recreation Area, MT
October 24, 2015
Robert Niese

The Tamarack colors were in full swing around Missoula last week. They appear to be fading a bit now, but we’ll soon forget to mourn their bare branches when they become adorned with snow!

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Malacosoma sp. “Tent Moth” Lasiocampidae, pupa on
Larix occidentalis “Western Larch” Pinaceae

Apgar Lookout Trail, Glacier National Park, MT
October 9, 2015
Robert Niese

The trails around Apgar are rife with Lasiocampidae pupae. They’ve spun their webby cocoons in every manner of tree, shrub, and man-made structure. Around Missoula, it wasn’t a very big year for tent moth caterpillars, but only a hundred miles away in Glacier National Park, Malacosoma numbers were significantly higher. These species go through regular boom and bust cycles and some years they become so abundant that entire forests can get defoliated. In my search of the literature, it appears that these moths overwinter as eggs, not as pupae. These pupating individuals certainly won’t survive the oncoming cold if that is indeed the case.

Apgar, Glacier National Park - by Robert NieseGoat Lick, Glacier National Park - by Robert NiesePopulus Leaf, Glacier National Park - by Robert NieseApgar, Glacier National Park - by Robert Niese   Two Medicine, Glacier National Park - by Robert NieseApgar, Glacier National Park - by Robert Niese

Fall is in full swing here in Montana!

I made it up to Glacier National Park this weekend to experience some fall foliage firsthand. It was absolutely stunning!

Here’s a brief guide to foliage colors in Western Montana!

Yellow:

  • Members of Salicaceae (Cottonwoods, Aspens, Poplars, Willows) and Betulaceae (Alders, Birch) dominate the yellow palate of our PNW hillsides. These species begin turning in September and their colors will persist, depending on rain and wind, until late October.
  • Larch (Larix) is our only deciduous conifer in the PNW. Depending on elevation, Larch will begin turning between the first and third weeks of October.
  • Bracken Fern (Pteridium aquilinum) and Thimbleberry (Rubus parviflorus) also maintain a substantial degree of yellowness early in the fall before turning pale brown in October.

Red:

  • Red fall foliage in western Montana is largely restricted to the understory.
  • Ericaceous shrubs such as Huckleberries (Vaccinium) change color depending on sun exposure. On exposed hillsides, they’ll be red before August, while in dense forests, they may only begin changing in October.
  • Rosaceous shrubs such as Oceanspray (Holoduscus), Ninebark (Physocarpus), Spiraea, Hawthorn (Crataegus), and Rose (Rosa) also tend to go through a red phase in their color change. While some of these species appear to start early (September), most of their change will persist well into October and even November.
  • Red-osier Dogwood (Cornus sericea) has an interesting color change. Here in the riparian areas of Western Montana, they appear to go through a green and maroon phase, which is quite lovely, before losing their leaves entirely. Fortunately, even after losing their leaves, these shrubs have phenomenal red stems that definitely supplement the colors of fall.
  • Maple (Acer) also go through a red phase here in western Montana. These native species appear to have dropped most of their leaves by mid-October.

Species with little color change:

  • I’ve noticed several dominant deciduous trees and shrubs that don’t appear to change color considerably with the seasons. Of these, Ceanothus and Symphoricarpos are the most abundant.
  • Ceanothus tends to keep its green foliage throughout the year or turn straight to brown in the fall.
  • Snowberries (Symphoricarpos) appear to do a variety of things, but here in western Montana, they generally drop their leaves quickly without much ado.

Letharia vulpina “Wolf Lichen” on
Pinus ponderosa “Ponderosa Pine” Pinaceae

Mt. Sentinel, Lolo National Forest, MT
September 12, 2015
Robert Niese

Wolf lichen is a striking, extremely abundant lichen in our dry Ponderosa Pinelands here in the PNW. It’s electric yellow-green color comes from a compound produced by the fungus known as vulpinic acid. It is relatively toxic and in ancient Europe concentrated vulpinic acid was traditionally used as a poison for killing wolves (hence it’s common name). Here in the PNW, however, native peoples use the lichen as a dye for fabrics and baskets. You can learn how to make your own dyes from lichens like Letharia here.

Larix occidentalis “Western Larch” Pinaceae

Seeley Lake, MT
September 13, 2014
Robert Niese

 

Larch cones are simply beautiful. Two small, winged seeds hide beneath each scale, waiting to be dispersed on the wind as they fall to the ground when the cone matures. Each scale also bears a single long, pointed bract, giving the cone a delicate, yet spiky appearance. This particular cone also bears many resin crystals which may have been produced by damage from seed predators such as Red Crossbills. If you ever have the opportunity to visit the Seeley Lake region in the late summer or early fall, you would not be disappointed. These deciduous conifers transform into golden spires that light-up our mountainsides in a spectacular patchwork of fiery pillars scattered among rich, evergreen firs and pines. It is unlike any fall scenery anywhere else in the world.

Pseudotsuga menziesii “Douglas Fir” Pinaceae

Tacoma, WA
May 18, 2013
Robert Niese

A Pacific Northwest Indian legend explains where the Doug-fir got its unmistakable leafy bracts (in between the scales of the cone), suggesting that, long ago during an intense fire, tiny mice seeking shelter from the flames hid themselves between the scales of the Doug-fir cones. Today we see their tiny tails and back feet poking out of the cones!

Larix occidentalis “Western Larch” Pinaceae (cone with evidence of seed predation by Tamiasciurus hudsonicus Red Squirrel)

Seeley Lake, MT
September 13, 2014
Robert Niese

Red Squirrels are cone specialists and create massive debris piles, called middens, in areas where they regularly eat (typically atop a stump, fallen log, or low, broad tree branch). These middens are easy to spot and are often more than a meter in width. In Western Washington, these cone middens are usually created by the Red Squirrel’s cousin, the Douglas Squirrel (T. douglasii).

Larix occidentalis “Western Larch” Pinaceae
with Bryoria sp. “Tree-hair Lichen" 

Seeley Lake, MT
September 13, 2014
Robert Niese

Larch is one of North America’s only deciduous conifers. Here in western Montana, needles are just beginning to turn yellow in mid-September.
Bryoria is a common lichen throughout the PNW and was once a common food source for more than 40 local tribes, in spite of nearly indistinguishable toxic species co-occurring throughout most of their range.