The soft, grass-like leaves of Kniphofia angustifolia grow tufted from the base, initially erect then arching. The dull blue-green blades are slightly keeled on their lower surfaces. Leaf dimensions are from 40 cm to 70 cm long by only 2 mm to 3 mm wide. The specific epithet, angustifolia, is derived from the Latin words angustus meaning narrow and folia meaning leaves, referring to the shape of the leaves.
The inflorescence is a loose, erect raceme of short-stalked, tubular flowers around a slender stem. The raceme is from 10 cm to 30 cm long and about 6 cm wide. The pendulous flowers are cylindrical, between 19 mm to 32 mm long. Their bases do not bulge and the tiny lobes around their mouths curve out slightly. The perianth colours vary from red, orange, yellow, cream or white. Flowering happens from late spring to after midautumn (Pooley, 1998; iNaturalist).