This is widespread in eastern and central North America, but concentrated in the mid-west and largely restricted to remnants of native grassland on calcareous soils. See notes under tetanica and woodii. These species in Section Paniceae can be difficult to distinguish from those in Section Granulares (crawei, granularis), but the descriptions and key in Y are particularly useful. Their perigynia tend to be less tightly packed in the spike; they are pale green to pale brown or nearly white, and often somewhat glaucous (versus green to yellowish-brown); they are widest above the middle and tapered at the base (versus widest at or below middle and more rounded at base), tightly enveloping the fruit (versus loosely). Leaf blades have minute papillae on lower surfaces, at least near the base (versus smooth). Plants consistently have long rhizomes, producing open stands of culms (versus rhizomatous or clumped).