If a flower has four petals arranged in a cross, there's a good chance it's in the mustard family. Flowers are organized alphabetically by genus and species. Hover over a photo series to control the images.
This plant was formerly placed in Arabis. The flowers can be mostly white to begin with, in which case they turn lavender as they wither. The examples I found had plenty of lavender to begin with. As the flower dies, small spikes—the seed pods—take their place.
Shepherd's Purse (Capsella bursa-pastoris)
Shepherd's Purse is an inconspicuous weed with tiny white flowers. The giveaway is the distinctively shaped seed pods. This introduced species comes from the Mediterranean area, where the seed pods were thought to resemble the leather purses worn by shepherds (in the days before pockets).
Blue Mustard (Chorispora tenella)
Other names include crossflower, beanpodded mustard, chorispora, purple mustard, and tenella mustard. Look for skinny spikes below the flowers; those are the seed pods. According to the New Mexico Wildflowers app, this species "grows only in the most disturbed of settings." Given such a setting (for example, an area that was recently bladed), it can create a carpet of green and purple.
According to the SEINET web site, "To distinguish among the various species of Descurainia, focus on the shape, size, and orientation of the seed pods." As a casual observer of wildflowers, I tend to think of such fine-grained examinations as getting into the weeds (sorry). Still, I'll provide tentative species names for the photos that follow.
I suspect that the photos shown above are of Western tansy-mustard, Descurainia pinnata, based on the size and shape of the seed pods (they remind me of the blades on butter knives). Also, the leaves look about right.
In April 2023, in Albuquerque's North Valley, a different species of tansy-mustard was having a banner year. Notice how the seed pods on this species are more tubular, and that the leaves are more feathery than those on my alleged Western tansy-mustard. I suspect these photos of being Descuriana sophia, which has various common names including herb-Sophia and flixweed. That particular species is non-native.
Spectacle Pod (Dimorphocarpa wislizeni)
In Albuquerque, Spectacle Pod is a common weed that blooms throughout the warm months. In April 2019, I found it running riot along the lower Embudito Trail. The flowers occur in clusters on tall stalks. The easy way to identify this species is the seeds that form below the flowers. The seeds supposedly look like spectacles; to me they look more like the fronts of the lab goggles I wore in chemistry class.
As summer turns to fall, you may encounter plants where the signature pods are mostly or entirely gone, but where the flowers are still blooming.
Draba, Whitlow-Grass (Draba)
Western Wallflower (Erysimum capitatum)
Western wallflowers are typically yellow at the elevations where people usually encounter them, including in juniper-pinyon woodlands. High in the mountains they're orange or even a stunning red. All of those variants are shown here.
New Mexico has multiple species of pepperweed, some native, others not. The tiny individual flowers may be difficult to make out. A close look shows the Mustard Family's classic cross-shaped arrangement of four petals. You can see that in the thumbnail to the left.
Sweet Alyssum (Lobularia maritima)
Difficult to believe that sweet alyssum qualifies as a New Mexico wildflower, but it does, just barely. I suspect that on occasion, a bird spreads a seed from a garden nearby.
Watercress (Nasturtium officinale)
As a young man in Arizona I sometimes hiked with a small bottle of vinaigrette, in case I came across a patch of watercress. I stopped doing that, however, due to the spread of giardia. Watercress is an Old World species but is widely naturalized in North America. Look for watercress in permanent shallow streams with clear, fast-flowing water. If you eat what you find, however, you're eating all the microbes and parasites in the stream.
In the Albuquerque area, the best place I know to see watercress is at the source of Carlito Springs, uphill from the main visitor area.
Despite the name of the genus, the flowers we call nasturtiums are unrelated to the watercresses.
The mountains around Albuquerque host several species of bladderpod. The newly formed seed pods look like tiny green balloons. (Before rubber, balloons were made from animal bladders, hence the common name.) You may find bladderpod listed under the genus Lesquerella, which now considered a synonym for Physaria.
Jim Hill Mustard, Tall Tumblemustard (Sisymbrium altissimum)
This look like (and is first cousin to) the London Rocket that's such a profuse weed in Albuquerque. One difference is that London Rocket flowers usually are under 4 mm long, while the petals on this species usually are at least 5 mm long.
London Rocket (Sisymbrium irio)
This is my nominee for Albuquerque's official weed. London rocket prefers bare ground, which is common in Albuquerque yards. Without a water source it's scraggly but hardy. Given some moisture, it can form lush stands. Even a modest plant produces hundreds or thousands of tiny seeds, allowing it to aggressively colonize untended yards. London rocket is an Old World species, but not native to London or any other part of the British Isles. It allegedly got its name after spreading rapidly through London after the Great Fire of 1666.