I really, really don't want to go down the grass ID rabbit hole. There are more than 300 grass species in New Mexico, and they don't have obvious flowers to help me identify them. But from time to time I'll take and post pictures, in part to learn and in part to share what I've learned.
If your "grass" has a stem that's triangular in cross section, it's actually a sedge.
If you see a mistake, click on the Contact tab to let me know. The images will be in alphabetical order by genus and species. Hover over a photo series with your cursor to control the images.
Sideoats Grama (Bouteloua curtipendula)
This species puts out stalks from which the flowers (and later the seeds) hang.
Blue Grama (Bouteloua gracilis)
This grama grass puts up a stalk, with the flowering part out to one side (other species of grama grass do the same). A few New Mexicans have created puffy lawns out of this species but its ordinary habit is to grow in discontinuous clumps.
Feather Fingergrass, Zacate Lagunero (Chloris virgata)
Large Barnyard Grass, Zacate de Agua (Echinochloa crus-galli)
Large barnyard grass is an Old World species that has spread around the world. I found clumps of this grass with its distinctly purple panicles (clusters of flowers) along a high-water channel of the Rio Grande, and on the bank of the main channel.
Slender Wheatgrass (Elymus trachycaulus)
Arizona Fescue (Festuca arizonica)
This seems to be the signature grass of the upper Sandia Mountains, including in the ski runs.
Feathertop (Pennisetum villosum)
A non-native species, introduced to the New World from the old as an ornamental. I found it next to a channel of the Rio Grande; presumably the first seed washed downstream.
Carrizo, Common Reed (Phragmites australis)
This patch of carrizo is growing next to an irrigation drainage ditch, itself next to the National Hispanic Cultural Center.
Common Panic Grass, Witch Grass? (Panicum capillare?)
In one of my pictures there appears to be a small cloud in the grass. This effect was produced by dew-covered panicles sparkling in the sun.
Johnson Grass, Johnsongrass (Sorghum halepense)
Johnson grass (one or two words) was imported from the Old World as a source of hay and forage, but is invasive and potentially harmful to cattle. According to the SEINEt web page for this species, it's "commonly found along irrigation ditches and in floodplains in the Southwest." I found this clump at the mouth of Tijeras Arroyo.