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. But from time to time I'll take and post pictures, in part to learn and in part to share what I think I've learned. If you see a mistake, please click on the Contact tab to let me know.
If your "grass" has a stem that's triangular in cross section, it's a sedge.
The images are in alphabetical order by genus and species. Hover over a photo series with your cursor to control the images.
While walking through undistinguished-looking clumps of desert grass, in the Sandia foothills, I noticed one whose seed heads were puffy. My photos may be of cane beardgrass (or cane bluestem), Bothriochloa barbinodis.
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.
There are 14 documented species of Bromus in Bernalillo County alone. I'm already climbing out on a limb by taking the ID to genus, so no way I'm drilling down to species.
Feather Fingergrass, Zacate Lagunero (Chloris virgata)
Bermuda Grass (Cynodon dactylon)
Many lawns in the desert Southwest consist of this species, due to its tolerance of heat, drought, and soil salinity. When kept mowed, its distinctive feature is its runners. Left to itself, it forms low carpets or mounds with flower heads that remind me of one-pole outdoor clothes dryers.
Bermuda grass doesn't come from Bermuda; it's an Old World species. It has escaped into the wild, so is included here.
Orchard Grass (Dactylis glomerata)
Going out on a limb this time. My ID is based on the flower heads, the breadth of the leaves compared to, say, Arizona fescue, and the way the leaves attach (shown to the left). I really like this discussion of how to ID orchard grass (also orchardgrass or cat grass).
Desert Salt Grass (Distichlis spicata)
Also known as coastal salt grass. As the names suggest, these low tufts form in salty soil.
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.
Nodding Wild Rye (Elymus canadensis)
Slender Wheatgrass (Elymus trachycaulus)
Indian Ricegrass (Eriocoma hymenoides)
The airy, branching seed heads, with each "branch" ending in a single obvious seed pod, this native grass is fairly easy to recognize. Indian ricegrass is common on well-drained soils throughout the U.S. West. As its name suggests, Native Americans harvested the seeds for food.
Arizona Fescue (Festuca arizonica)
This seems to be the signature grass of the upper Sandia Mountains, including in the ski runs.
Needle-and-Thread Grass (Hesperostipa comata)
If allowed to grow into healthy stands (as opposed to being eaten to the ground by cows), this grass puts on a show each spring. Each seed-plus-awn bends over, forming a light-catching contrast between the mostly vertical main part of each plant and the mostly horizontal seeds-plus-awns. Examined up close, each seed-plus-awn looks a little like a needle and (stiff) thread. Once the seeds mature, the awns twist and untwist with moisture changes, drilling the seeds into the ground.
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)
My photos document two encounters with what I think is common panic grass. In the open space at the western base of the Sandias, I encountered puffy mounds of grass with airy panicles. In August, the panicles still had a purple tinge; a month later they were dry and brown. In September also found the same grass, still green, among taller wetland plants at the edge of a nature pond. In one picture from the latter set, there appears to be a small cloud in the grass. This effect was produced by dew-covered panicles sparkling in the sun.
Ravenna Grass, Elephant Grass (Saccharum ravennae)
This taller-than-you-are grass is reminiscent of pampas grass (Cortaderia selloana), but is hardier (it is sometimes sold under the name "hardy pampas grass"). One difference is that pampas grass flower/seed stalks barely rise above the clump of leaves, while Ravenna grass flower/seed stalks extend well above the clump of leaves. Ravenna grass is exotic and invasive, and common along the local stretch of the Rio Grande.
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.