There’s more to grass than what you see growing in your lawn.
While they might not look like it, grasses are actually flowering plants. Some grass species are annuals while others are long-lived perennials that have deep, extensive underground root systems that allow them to survive year after year of summer droughts. In the Bay Area, perennial grasses like purple needle grass (Nassella pulchra), red fescue (Festuca rubra), and California oatgrass (Danthonia californica), along with a multitude of other plant species, make up an ecosystem called northern coastal prairie—the most diverse grassland type in North America. This type of grassland once covered large swaths of the California coast, but now just less than one percent remains as a result of farming, land development, and invasive species. Small pockets of coastal prairie can be found in the Golden Gate National Recreation Area and relatively large prairie ecosystems still exist at Point Reyes National Seashore.
Unfortunately, historic and on-going habitat disturbance from over-grazing, frequent fires, brush clearing, and agriculture have made exotic annual grasslands the most common type in the San Francisco Bay Area national parks and surrounding areas. In these areas invasive species like wild oats (Avena barbata and A. fatua), Italian wild rye (Lolium multiflorum) brome grasses (Bromus diandrus, B. hordeaceus, and B. madritensis), and annual fescues (Vulpia myuros and V. bromoides) cover areas that were once wildflower fields, perennial grasslands, shrublands, or even woodlands.