Compare it, point-by-point, with a scientific description. Don't skip any points.

Here's one from Purdue:

"Loose to densely tufted, rather short-lived perennial; culms smooth, 40-150 cm tall, stiffly erect or ascending, bent from a bulbous base to form large clumps; basal nodes generally very short, swollen or bulbous; leaf-blades elongate, flat, 10-30 cm long, 5-8 mm broad, saber-shaped, tapering to a very thin point; top leaf-blade shorter than the other leaves and extending sharply upward, with a longer clinging leaf-sheath; seed-heads bristly, cylindrical, very dense, large, 4-12.5 cm long, 0.6 cm in diameter; spikelets crowded, flattened, covered with stiff hairs; glumes about 3.5 mm long, truncate with a short awn 1 mm long, pectinate-ciliate on the keel; 1 or 2 lower internodes becoming swollen into 'bulbs' or 'corms' which store some carbohydrates until plant blooms; root system fibrous and rather shallow, not spreading laterally. Fl. summer and fall. Seeds 2,000,000 to 2,712,150/kg (Reed, 1976)."