(Salicaceae)

Trees are organized alphabetically by genus and species. Hover over a photo series to control the images.

Silver Poplar or White Poplar (Populus alba)

These strikingly handsome trees were introduced from the Old World. In New Mexico they have escaped into the wild a few times, or at least have spread from plantings (like aspens, they can pop up new trees from their roots). In the Albuquerque area, the best place I know to see them is along the lower Crest Highway (on the left side of the road as you head up, next to a pond).

I was looking at those very trees when a local resident, out walking his dog, informed me that they were aspens. I can see why he thought so; the bark on the branches and upper trunks is an aspen-like white, and the leaves tremble in a good breeze. However, the leaves don't have the classic aspen shape, they're dark for an aspen leaf, and the undersides of the leaves are silvery or even white. Also, long-established lower trunks have thick corrugated bark more like a cottonwood's.

Cottonwood (Populus deltoides)

There seem to be many opinions as to how to classify Albuquerque's cottonwoods. One popular option is Populus deltoides wislizeni. 

In the spring, catkins with any amount of red indicate a male tree, while all-green catkins indicate a female tree. The females then produce cluster of green "cotton bolls" that remind me of clusters of unripe grapes. Each female tree then releases thousands of tiny seeds, each with "cotton" to help it spread in the wind. People get annoyed because this "cotton" accumulates where it's not wanted, but cottonwoods are not entirely to blame—the local willows produce "cotton" as well.

Young cottonwood leaves are a beautiful emerald green but become duller as the summer wears on. If the fall begins with a sharp frost, the leaves turn to gold all at once and the effect is spectacular. If the fall cool-down is slow, leaves turn yellow and then brown separately and the fall color effect is more muted. The leaves tend to stay attached long after they've died, and rustle in the winter wind.

Quaking Aspen (Populus tremuloides)

Usually just referred to as aspens, these trees have leaves that resemble those of their cousins, the cottonwoods. But aspen petioles (leaf stems) are flattened rather than circular in cross-section, so the leaves twist in the slightest breeze. Hence the "quaking" part of the full common name. They come into their glory in the fall, when the golden leaves contrast with the white bark of the trunks. Very rarely, aspen leaves turns red instead.

The smooth white bark is a tempting canvas for anyone with a pocket knife. The technical term for the resulting art or inscription is dendroglyph. At the bases of the oldest aspens, the bark can be quite rough.

If you see galls on aspen leaves, those might be due to a mite I documented on a different page.

Willow (Salix): Native Species

The New Mexico Wildflowers app shows 31 species of Salix, and the SEINET checklist for Bernalillo County lists seven species. Many species look similar and some species hybridize. Detailed information sources are not always helpful to duffers like me. Take, for example, the SEINET web page for one of the local species, peach-leaf willows (Salix amygdaloides). The web page explains that for this species, “the leaf blades are usually dull on the upper surface, bearing rudimentary stipules” and that I should look for “glabrous branchlets.” Stipules? Glabrous? The page also mentions that this species of willow is also known as Salix amygdaloides var. wrightii, Salix nigra var. amygdaloides, Salix nigra var. wrightii, and Salix wrightii. 

Cripes!

Not being a botanist, I have a mental checklist that begins by dividing local willows into narrower-leaved and broader-leaved. The following applies to the seven species on the Bernalillo County checklist.

The narrower-leaved willows include the aptly named narrow-leaf willow (S. exigua) and Goodding’s black willow (S. gooddingii). The SEINET web page for narrow-leaf willows now comes to the rescue: S. exigua “is one of two willows that can be found along low-elevation rivers in the Southwest. The other, S. gooddingii, grows into a well-developed tree with lanceolate leaves 9–16 mm wide, with toothed edges. S. exigua, in contrast, is clonal and tends to grow in dense thickets; it never grows into a well developed tree, but instead has many woody stems only a few centimeters in diameter; and the leaves are much narrower, only 2–9 mm wide. Look also for the young branches which are often distinctly red-brown.”

Thus, my mental checklist for narrower-leaved willows along the local Rio Grande turns actual trees into Goodding’s black willow, while dense thickets of “baby” willows (often with reddish branches) become narrow-leaf willows.

The broader-leaved wild willow species in my home county include the aforementioned peach-leaf willows, Bebb willows (S. bebbiana), dewy-stem willows (S. irrorata), and shining willows (S. lucida). While I don’t feel the need to break them down further, it seems that people tend to refer to broader-leaf willows in the Albuquerque and Corrales Bosques as peach-leaf willows.

Finally, the leaves on arroyo willows (S. lasiolepsis) fall somewhere between narrow and broad. I'll cross that bridge when I come to it.

Anyway, that (plus taking photos to check later) is what usually works for me. Maybe it’ll work for you as well.

Weeping Willow (Salix cf. babylonica)

It never occurred to me that I should include weeping willows in this online photo series, until I saw one in the Bosque. Hopefully everyone can tell a weeping willow, with its hanging branches, from other willows. Weeping willows are usually classified as Salix babylonica, but be warned that the they also include interspecies hybrids.